All Wio Terminal now working except playing audio

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/include/README

@@ -0,0 +1,39 @@
+
+This directory is intended for project header files.
+
+A header file is a file containing C declarations and macro definitions
+to be shared between several project source files. You request the use of a
+header file in your project source file (C, C++, etc) located in `src` folder
+by including it, with the C preprocessing directive `#include'.
+
+```src/main.c
+
+#include "header.h"
+
+int main (void)
+{
+ ...
+}
+```
+
+Including a header file produces the same results as copying the header file
+into each source file that needs it. Such copying would be time-consuming
+and error-prone. With a header file, the related declarations appear
+in only one place. If they need to be changed, they can be changed in one
+place, and programs that include the header file will automatically use the
+new version when next recompiled. The header file eliminates the labor of
+finding and changing all the copies as well as the risk that a failure to
+find one copy will result in inconsistencies within a program.
+
+In C, the usual convention is to give header files names that end with `.h'.
+It is most portable to use only letters, digits, dashes, and underscores in
+header file names, and at most one dot.
+
+Read more about using header files in official GCC documentation:
+
+* Include Syntax
+* Include Operation
+* Once-Only Headers
+* Computed Includes
+
+https://gcc.gnu.org/onlinedocs/cpp/Header-Files.html

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/lib/README

@@ -0,0 +1,46 @@
+
+This directory is intended for project specific (private) libraries.
+PlatformIO will compile them to static libraries and link into executable file.
+
+The source code of each library should be placed in a an own separate directory
+("lib/your_library_name/[here are source files]").
+
+For example, see a structure of the following two libraries `Foo` and `Bar`:
+
+|--lib
+|  |
+|  |--Bar
+|  |  |--docs
+|  |  |--examples
+|  |  |--src
+|  |     |- Bar.c
+|  |     |- Bar.h
+|  |  |- library.json (optional, custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
+|  |
+|  |--Foo
+|  |  |- Foo.c
+|  |  |- Foo.h
+|  |
+|  |- README --> THIS FILE
+|
+|- platformio.ini
+|--src
+   |- main.c
+
+and a contents of `src/main.c`:
+```
+#include <Foo.h>
+#include <Bar.h>
+
+int main (void)
+{
+  ...
+}
+
+```
+
+PlatformIO Library Dependency Finder will find automatically dependent
+libraries scanning project source files.
+
+More information about PlatformIO Library Dependency Finder
+- https://docs.platformio.org/page/librarymanager/ldf.html

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/platformio.ini

@@ -0,0 +1,23 @@
+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+[env:seeed_wio_terminal]
+platform = atmelsam
+board = seeed_wio_terminal
+framework = arduino
+lib_deps =
+    seeed-studio/Seeed Arduino FS @ 2.1.1
+    seeed-studio/Seeed Arduino SFUD @ 2.0.2
+    seeed-studio/Seeed Arduino rpcWiFi @ 1.0.5
+    seeed-studio/Seeed Arduino rpcUnified @ 2.1.3
+    seeed-studio/Seeed_Arduino_mbedtls @ 3.0.1
+    seeed-studio/Seeed Arduino RTC @ 2.0.0
+    bblanchon/ArduinoJson @ 6.17.3
+    contrem/arduino-timer @ 2.3.0

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/src/config.h

@@ -0,0 +1,93 @@
+#pragma once
+
+#define RATE 16000
+#define SAMPLE_LENGTH_SECONDS 4
+#define SAMPLES RATE * SAMPLE_LENGTH_SECONDS
+#define BUFFER_SIZE (SAMPLES * 2) + 44
+#define ADC_BUF_LEN 1600
+
+const char *SSID = "<SSID>";
+const char *PASSWORD = "<PASSWORD>";
+
+const char *SPEECH_API_KEY = "<API_KEY>";
+const char *SPEECH_LOCATION = "<LOCATION>";
+const char *LANGUAGE = "<LANGUAGE>";
+
+const char *TOKEN_URL = "https://%s.api.cognitive.microsoft.com/sts/v1.0/issuetoken";
+const char *SPEECH_URL = "https://%s.stt.speech.microsoft.com/speech/recognition/conversation/cognitiveservices/v1?language=%s";
+
+const char *TEXT_TO_TIMER_FUNCTION_URL = "http://<IP_ADDRESS>:7071/api/text-to-timer";
+const char *GET_VOICES_FUNCTION_URL = "http://<IP_ADDRESS>:7071/api/get-voices";
+const char *TEXT_TO_SPEECH_FUNCTION_URL = "http://<IP_ADDRESS>:7071/api/text-to-speech";
+
+const char *TOKEN_CERTIFICATE =
+    "-----BEGIN CERTIFICATE-----\r\n"
+    "MIIF8zCCBNugAwIBAgIQAueRcfuAIek/4tmDg0xQwDANBgkqhkiG9w0BAQwFADBh\r\n"
+    "MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3\r\n"
+    "d3cuZGlnaWNlcnQuY29tMSAwHgYDVQQDExdEaWdpQ2VydCBHbG9iYWwgUm9vdCBH\r\n"
+    "MjAeFw0yMDA3MjkxMjMwMDBaFw0yNDA2MjcyMzU5NTlaMFkxCzAJBgNVBAYTAlVT\r\n"
+    "MR4wHAYDVQQKExVNaWNyb3NvZnQgQ29ycG9yYXRpb24xKjAoBgNVBAMTIU1pY3Jv\r\n"
+    "c29mdCBBenVyZSBUTFMgSXNzdWluZyBDQSAwNjCCAiIwDQYJKoZIhvcNAQEBBQAD\r\n"
+    "ggIPADCCAgoCggIBALVGARl56bx3KBUSGuPc4H5uoNFkFH4e7pvTCxRi4j/+z+Xb\r\n"
+    "wjEz+5CipDOqjx9/jWjskL5dk7PaQkzItidsAAnDCW1leZBOIi68Lff1bjTeZgMY\r\n"
+    "iwdRd3Y39b/lcGpiuP2d23W95YHkMMT8IlWosYIX0f4kYb62rphyfnAjYb/4Od99\r\n"
+    "ThnhlAxGtfvSbXcBVIKCYfZgqRvV+5lReUnd1aNjRYVzPOoifgSx2fRyy1+pO1Uz\r\n"
+    "aMMNnIOE71bVYW0A1hr19w7kOb0KkJXoALTDDj1ukUEDqQuBfBxReL5mXiu1O7WG\r\n"
+    "0vltg0VZ/SZzctBsdBlx1BkmWYBW261KZgBivrql5ELTKKd8qgtHcLQA5fl6JB0Q\r\n"
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+    "N2oV7vQ17wjMN+LXa2rjj/b4ZlZgXVojDmAjDwIRdDUujQu0RVsJqFLMzSIHpp2C\r\n"
+    "Zp7mIoLrySay2YYBu7SiNwL95X6He2kS8eefBBHjzwW/9FxGqry57i71c2cDAgMB\r\n"
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+    "CCsGAQUFBwEBBGowaDAkBggrBgEFBQcwAYYYaHR0cDovL29jc3AuZGlnaWNlcnQu\r\n"
+    "Y29tMEAGCCsGAQUFBzAChjRodHRwOi8vY2FjZXJ0cy5kaWdpY2VydC5jb20vRGln\r\n"
+    "aUNlcnRHbG9iYWxSb290RzIuY3J0MHsGA1UdHwR0MHIwN6A1oDOGMWh0dHA6Ly9j\r\n"
+    "cmwzLmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEdsb2JhbFJvb3RHMi5jcmwwN6A1oDOG\r\n"
+    "MWh0dHA6Ly9jcmw0LmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEdsb2JhbFJvb3RHMi5j\r\n"
+    "cmwwHQYDVR0gBBYwFDAIBgZngQwBAgEwCAYGZ4EMAQICMBAGCSsGAQQBgjcVAQQD\r\n"
+    "AgEAMA0GCSqGSIb3DQEBDAUAA4IBAQB2oWc93fB8esci/8esixj++N22meiGDjgF\r\n"
+    "+rA2LUK5IOQOgcUSTGKSqF9lYfAxPjrqPjDCUPHCURv+26ad5P/BYtXtbmtxJWu+\r\n"
+    "cS5BhMDPPeG3oPZwXRHBJFAkY4O4AF7RIAAUW6EzDflUoDHKv83zOiPfYGcpHc9s\r\n"
+    "kxAInCedk7QSgXvMARjjOqdakor21DTmNIUotxo8kHv5hwRlGhBJwps6fEVi1Bt0\r\n"
+    "trpM/3wYxlr473WSPUFZPgP1j519kLpWOJ8z09wxay+Br29irPcBYv0GMXlHqThy\r\n"
+    "8y4m/HyTQeI2IMvMrQnwqPpY+rLIXyviI2vLoI+4xKE4Rn38ZZ8m\r\n"
+    "-----END CERTIFICATE-----\r\n";
+
+const char *SPEECH_CERTIFICATE =
+    "-----BEGIN CERTIFICATE-----\r\n"
+    "MIIF8zCCBNugAwIBAgIQCq+mxcpjxFFB6jvh98dTFzANBgkqhkiG9w0BAQwFADBh\r\n"
+    "MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3\r\n"
+    "d3cuZGlnaWNlcnQuY29tMSAwHgYDVQQDExdEaWdpQ2VydCBHbG9iYWwgUm9vdCBH\r\n"
+    "MjAeFw0yMDA3MjkxMjMwMDBaFw0yNDA2MjcyMzU5NTlaMFkxCzAJBgNVBAYTAlVT\r\n"
+    "MR4wHAYDVQQKExVNaWNyb3NvZnQgQ29ycG9yYXRpb24xKjAoBgNVBAMTIU1pY3Jv\r\n"
+    "c29mdCBBenVyZSBUTFMgSXNzdWluZyBDQSAwMTCCAiIwDQYJKoZIhvcNAQEBBQAD\r\n"
+    "ggIPADCCAgoCggIBAMedcDrkXufP7pxVm1FHLDNA9IjwHaMoaY8arqqZ4Gff4xyr\r\n"
+    "RygnavXL7g12MPAx8Q6Dd9hfBzrfWxkF0Br2wIvlvkzW01naNVSkHp+OS3hL3W6n\r\n"
+    "l/jYvZnVeJXjtsKYcXIf/6WtspcF5awlQ9LZJcjwaH7KoZuK+THpXCMtzD8XNVdm\r\n"
+    "GW/JI0C/7U/E7evXn9XDio8SYkGSM63aLO5BtLCv092+1d4GGBSQYolRq+7Pd1kR\r\n"
+    "EkWBPm0ywZ2Vb8GIS5DLrjelEkBnKCyy3B0yQud9dpVsiUeE7F5sY8Me96WVxQcb\r\n"
+    "OyYdEY/j/9UpDlOG+vA+YgOvBhkKEjiqygVpP8EZoMMijephzg43b5Qi9r5UrvYo\r\n"
+    "o19oR/8pf4HJNDPF0/FJwFVMW8PmCBLGstin3NE1+NeWTkGt0TzpHjgKyfaDP2tO\r\n"
+    "4bCk1G7pP2kDFT7SYfc8xbgCkFQ2UCEXsaH/f5YmpLn4YPiNFCeeIida7xnfTvc4\r\n"
+    "7IxyVccHHq1FzGygOqemrxEETKh8hvDR6eBdrBwmCHVgZrnAqnn93JtGyPLi6+cj\r\n"
+    "WGVGtMZHwzVvX1HvSFG771sskcEjJxiQNQDQRWHEh3NxvNb7kFlAXnVdRkkvhjpR\r\n"
+    "GchFhTAzqmwltdWhWDEyCMKC2x/mSZvZtlZGY+g37Y72qHzidwtyW7rBetZJAgMB\r\n"
+    "AAGjggGtMIIBqTAdBgNVHQ4EFgQUDyBd16FXlduSzyvQx8J3BM5ygHYwHwYDVR0j\r\n"
+    "BBgwFoAUTiJUIBiV5uNu5g/6+rkS7QYXjzkwDgYDVR0PAQH/BAQDAgGGMB0GA1Ud\r\n"
+    "JQQWMBQGCCsGAQUFBwMBBggrBgEFBQcDAjASBgNVHRMBAf8ECDAGAQH/AgEAMHYG\r\n"
+    "CCsGAQUFBwEBBGowaDAkBggrBgEFBQcwAYYYaHR0cDovL29jc3AuZGlnaWNlcnQu\r\n"
+    "Y29tMEAGCCsGAQUFBzAChjRodHRwOi8vY2FjZXJ0cy5kaWdpY2VydC5jb20vRGln\r\n"
+    "aUNlcnRHbG9iYWxSb290RzIuY3J0MHsGA1UdHwR0MHIwN6A1oDOGMWh0dHA6Ly9j\r\n"
+    "cmwzLmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEdsb2JhbFJvb3RHMi5jcmwwN6A1oDOG\r\n"
+    "MWh0dHA6Ly9jcmw0LmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEdsb2JhbFJvb3RHMi5j\r\n"
+    "cmwwHQYDVR0gBBYwFDAIBgZngQwBAgEwCAYGZ4EMAQICMBAGCSsGAQQBgjcVAQQD\r\n"
+    "AgEAMA0GCSqGSIb3DQEBDAUAA4IBAQAlFvNh7QgXVLAZSsNR2XRmIn9iS8OHFCBA\r\n"
+    "WxKJoi8YYQafpMTkMqeuzoL3HWb1pYEipsDkhiMnrpfeYZEA7Lz7yqEEtfgHcEBs\r\n"
+    "K9KcStQGGZRfmWU07hPXHnFz+5gTXqzCE2PBMlRgVUYJiA25mJPXfB00gDvGhtYa\r\n"
+    "+mENwM9Bq1B9YYLyLjRtUz8cyGsdyTIG/bBM/Q9jcV8JGqMU/UjAdh1pFyTnnHEl\r\n"
+    "Y59Npi7F87ZqYYJEHJM2LGD+le8VsHjgeWX2CJQko7klXvcizuZvUEDTjHaQcs2J\r\n"
+    "+kPgfyMIOY1DMJ21NxOJ2xPRC/wAh/hzSBRVtoAnyuxtkZ4VjIOh\r\n"
+    "-----END CERTIFICATE-----\r\n";

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/src/flash_stream.h

@@ -0,0 +1,69 @@
+#pragma once
+
+#include <Arduino.h>
+#include <HTTPClient.h>
+#include <sfud.h>
+
+#include "config.h"
+
+class FlashStream : public Stream
+{
+public:
+    FlashStream()
+    {
+        _pos = 0;
+        _flash_address = 0;
+        _flash = sfud_get_device_table() + 0;
+        
+        populateBuffer();
+    }
+
+    virtual size_t write(uint8_t val)
+    {
+        return 0;
+    }
+
+    virtual int available()
+    {
+        int remaining = BUFFER_SIZE - ((_flash_address - HTTP_TCP_BUFFER_SIZE) + _pos);
+        int bytes_available = min(HTTP_TCP_BUFFER_SIZE, remaining);
+
+        if (bytes_available == 0)
+        {
+            bytes_available = -1;
+        }
+
+        return bytes_available;
+    }
+
+    virtual int read()
+    {
+        int retVal = _buffer[_pos++];
+
+        if (_pos == HTTP_TCP_BUFFER_SIZE)
+        {
+            populateBuffer();
+        }
+
+        return retVal;
+    }
+
+    virtual int peek()
+    {
+        return _buffer[_pos];
+    }
+
+private:
+    void populateBuffer()
+    {
+        sfud_read(_flash, _flash_address, HTTP_TCP_BUFFER_SIZE, _buffer);
+        _flash_address += HTTP_TCP_BUFFER_SIZE;
+        _pos = 0;
+    }
+    
+    size_t _pos;
+    size_t _flash_address;
+    const sfud_flash *_flash;
+
+    byte _buffer[HTTP_TCP_BUFFER_SIZE];
+};

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/src/flash_writer.h

@@ -0,0 +1,60 @@
+#pragma once
+
+#include <Arduino.h>
+#include <sfud.h>
+
+class FlashWriter
+{
+public:
+    void init()
+    {
+        _flash = sfud_get_device_table() + 0;
+        _sfudBufferSize = _flash->chip.erase_gran;
+        _sfudBuffer = new byte[_sfudBufferSize];
+        _sfudBufferPos = 0;
+        _sfudBufferWritePos = 0;
+    }
+
+    void reset()
+    {
+        _sfudBufferPos = 0;
+        _sfudBufferWritePos = 0;
+    }
+
+    void writeSfudBuffer(byte b)
+    {
+        _sfudBuffer[_sfudBufferPos++] = b;
+        if (_sfudBufferPos == _sfudBufferSize)
+        {
+            sfud_erase_write(_flash, _sfudBufferWritePos, _sfudBufferSize, _sfudBuffer);
+            _sfudBufferWritePos += _sfudBufferSize;
+            _sfudBufferPos = 0;
+        }
+    }
+
+    void flushSfudBuffer()
+    {
+        if (_sfudBufferPos > 0)
+        {
+            sfud_erase_write(_flash, _sfudBufferWritePos, _sfudBufferSize, _sfudBuffer);
+            _sfudBufferWritePos += _sfudBufferSize;
+            _sfudBufferPos = 0;
+        }
+    }
+
+    void writeSfudBuffer(byte *b, size_t len)
+    {
+        for (size_t i = 0; i < len; ++i)
+        {
+            writeSfudBuffer(b[i]);
+        }
+    }
+
+private:
+    byte *_sfudBuffer;
+    size_t _sfudBufferSize;
+    size_t _sfudBufferPos;
+    size_t _sfudBufferWritePos;
+
+    const sfud_flash *_flash;
+};

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/src/language_understanding.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <Arduino.h>
+#include <ArduinoJson.h>
+#include <HTTPClient.h>
+#include <WiFiClient.h>
+
+#include "config.h"
+
+class LanguageUnderstanding
+{
+public:
+    int GetTimerDuration(String text)
+    {
+        DynamicJsonDocument doc(1024);
+        doc["text"] = text;
+
+        String body;
+        serializeJson(doc, body);
+
+        HTTPClient httpClient;
+        httpClient.begin(_client, TEXT_TO_TIMER_FUNCTION_URL);
+
+        int httpResponseCode = httpClient.POST(body);
+
+        int seconds = 0;
+        if (httpResponseCode == 200)
+        {
+            String result = httpClient.getString();
+            Serial.println(result);
+
+            DynamicJsonDocument doc(1024);
+            deserializeJson(doc, result.c_str());
+
+            JsonObject obj = doc.as<JsonObject>();
+            seconds = obj["seconds"].as<int>();
+        }
+        else
+        {
+            Serial.print("Failed to understand text - error ");
+            Serial.println(httpResponseCode);
+        }
+
+        httpClient.end();
+
+        return seconds;
+    }
+
+private:
+    WiFiClient _client;
+};
+
+LanguageUnderstanding languageUnderstanding;

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/src/main.cpp

@@ -0,0 +1,130 @@
+#include <Arduino.h>
+#include <arduino-timer.h>
+#include <rpcWiFi.h>
+#include <sfud.h>
+#include <SPI.h>
+
+#include "config.h"
+#include "language_understanding.h"
+#include "mic.h"
+#include "speech_to_text.h"
+#include "text_to_speech.h"
+
+void connectWiFi()
+{
+    while (WiFi.status() != WL_CONNECTED)
+    {
+        Serial.println("Connecting to WiFi..");
+        WiFi.begin(SSID, PASSWORD);
+        delay(500);
+    }
+
+    Serial.println("Connected!");
+}
+
+void setup()
+{
+    Serial.begin(9600);
+
+    while (!Serial)
+        ; // Wait for Serial to be ready
+
+    delay(1000);
+
+    connectWiFi();
+
+    while (!(sfud_init() == SFUD_SUCCESS))
+        ;
+
+    sfud_qspi_fast_read_enable(sfud_get_device(SFUD_W25Q32_DEVICE_INDEX), 2);
+
+    pinMode(WIO_KEY_C, INPUT_PULLUP);
+
+    mic.init();
+
+    speechToText.init();
+    textToSpeech.init();
+
+    Serial.println("Ready.");
+}
+
+auto timer = timer_create_default();
+
+void say(String text)
+{
+    Serial.println(text);
+    textToSpeech.convertTextToSpeech(text);
+}
+
+bool timerExpired(void *announcement)
+{
+    say((char *)announcement);
+    return false;
+}
+
+void processAudio()
+{
+    String text = speechToText.convertSpeechToText();
+    Serial.println(text);
+
+    int total_seconds = languageUnderstanding.GetTimerDuration(text);
+    if (total_seconds == 0)
+    {
+        return;
+    }
+
+    int minutes = total_seconds / 60;
+    int seconds = total_seconds % 60;
+
+    String begin_message;
+    if (minutes > 0)
+    {
+        begin_message += minutes;
+        begin_message += " minute ";
+    }
+    if (seconds > 0)
+    {
+        begin_message += seconds;
+        begin_message += " second ";
+    }
+
+    begin_message += "timer started.";
+
+    String end_message("Times up on your ");
+    if (minutes > 0)
+    {
+        end_message += minutes;
+        end_message += " minute ";
+    }
+    if (seconds > 0)
+    {
+        end_message += seconds;
+        end_message += " second ";
+    }
+
+    end_message += "timer.";
+
+    say(begin_message);
+
+    timer.in(total_seconds * 1000, timerExpired, (void *)(end_message.c_str()));
+}
+
+void loop()
+{
+    if (digitalRead(WIO_KEY_C) == LOW && !mic.isRecording())
+    {
+        Serial.println("Starting recording...");
+        mic.startRecording();
+    }
+
+    if (!mic.isRecording() && mic.isRecordingReady())
+    {
+        Serial.println("Finished recording");
+
+        processAudio();
+
+        mic.reset();
+    }
+
+    timer.tick();
+}

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/src/mic.h

@@ -0,0 +1,242 @@
+#pragma once
+
+#include <Arduino.h>
+
+#include "config.h"
+#include "flash_writer.h"
+
+class Mic
+{
+public:
+    Mic()
+    {
+        _isRecording = false;
+        _isRecordingReady = false;
+    }
+
+    void startRecording()
+    {
+        _isRecording = true;
+        _isRecordingReady = false;
+    }
+
+    bool isRecording()
+    {
+        return _isRecording;
+    }
+
+    bool isRecordingReady()
+    {
+        return _isRecordingReady;
+    }
+
+    void init()
+    {
+        analogReference(AR_INTERNAL2V23);
+        
+        _writer.init();
+
+        initBufferHeader();
+        configureDmaAdc();
+    }
+
+    void reset()
+    {
+        _isRecordingReady = false;
+        _isRecording = false;
+
+        _writer.reset();
+
+        initBufferHeader();
+    }
+
+    void dmaHandler()
+    {
+        static uint8_t count = 0;
+
+        if (DMAC->Channel[1].CHINTFLAG.bit.SUSP)
+        {
+            DMAC->Channel[1].CHCTRLB.reg = DMAC_CHCTRLB_CMD_RESUME;
+            DMAC->Channel[1].CHINTFLAG.bit.SUSP = 1;
+
+            if (count)
+            {
+                audioCallback(_adc_buf_0, ADC_BUF_LEN);
+            }
+            else
+            {
+                audioCallback(_adc_buf_1, ADC_BUF_LEN);
+            }
+
+            count = (count + 1) % 2;
+        }
+    }
+
+private:
+    volatile bool _isRecording;
+    volatile bool _isRecordingReady;
+    FlashWriter _writer;
+
+typedef struct
+    {
+        uint16_t btctrl;
+        uint16_t btcnt;
+        uint32_t srcaddr;
+        uint32_t dstaddr;
+        uint32_t descaddr;
+    } dmacdescriptor;
+
+    // Globals - DMA and ADC
+    volatile dmacdescriptor _wrb[DMAC_CH_NUM] __attribute__((aligned(16)));
+    dmacdescriptor _descriptor_section[DMAC_CH_NUM] __attribute__((aligned(16)));
+    dmacdescriptor _descriptor __attribute__((aligned(16)));
+
+    void configureDmaAdc()
+    {
+        // Configure DMA to sample from ADC at a regular interval (triggered by timer/counter)
+        DMAC->BASEADDR.reg = (uint32_t)_descriptor_section;                    // Specify the location of the descriptors
+        DMAC->WRBADDR.reg = (uint32_t)_wrb;                                    // Specify the location of the write back descriptors
+        DMAC->CTRL.reg = DMAC_CTRL_DMAENABLE | DMAC_CTRL_LVLEN(0xf);           // Enable the DMAC peripheral
+        DMAC->Channel[1].CHCTRLA.reg = DMAC_CHCTRLA_TRIGSRC(TC5_DMAC_ID_OVF) | // Set DMAC to trigger on TC5 timer overflow
+                                       DMAC_CHCTRLA_TRIGACT_BURST;             // DMAC burst transfer
+
+        _descriptor.descaddr = (uint32_t)&_descriptor_section[1];                    // Set up a circular descriptor
+        _descriptor.srcaddr = (uint32_t)&ADC1->RESULT.reg;                           // Take the result from the ADC0 RESULT register
+        _descriptor.dstaddr = (uint32_t)_adc_buf_0 + sizeof(uint16_t) * ADC_BUF_LEN; // Place it in the adc_buf_0 array
+        _descriptor.btcnt = ADC_BUF_LEN;                                             // Beat count
+        _descriptor.btctrl = DMAC_BTCTRL_BEATSIZE_HWORD |                            // Beat size is HWORD (16-bits)
+                             DMAC_BTCTRL_DSTINC |                                    // Increment the destination address
+                             DMAC_BTCTRL_VALID |                                     // Descriptor is valid
+                             DMAC_BTCTRL_BLOCKACT_SUSPEND;                           // Suspend DMAC channel 0 after block transfer
+        memcpy(&_descriptor_section[0], &_descriptor, sizeof(_descriptor));          // Copy the descriptor to the descriptor section
+
+        _descriptor.descaddr = (uint32_t)&_descriptor_section[0];                    // Set up a circular descriptor
+        _descriptor.srcaddr = (uint32_t)&ADC1->RESULT.reg;                           // Take the result from the ADC0 RESULT register
+        _descriptor.dstaddr = (uint32_t)_adc_buf_1 + sizeof(uint16_t) * ADC_BUF_LEN; // Place it in the adc_buf_1 array
+        _descriptor.btcnt = ADC_BUF_LEN;                                             // Beat count
+        _descriptor.btctrl = DMAC_BTCTRL_BEATSIZE_HWORD |                            // Beat size is HWORD (16-bits)
+                             DMAC_BTCTRL_DSTINC |                                    // Increment the destination address
+                             DMAC_BTCTRL_VALID |                                     // Descriptor is valid
+                             DMAC_BTCTRL_BLOCKACT_SUSPEND;                           // Suspend DMAC channel 0 after block transfer
+        memcpy(&_descriptor_section[1], &_descriptor, sizeof(_descriptor));          // Copy the descriptor to the descriptor section
+
+        // Configure NVIC
+        NVIC_SetPriority(DMAC_1_IRQn, 0); // Set the Nested Vector Interrupt Controller (NVIC) priority for DMAC1 to 0 (highest)
+        NVIC_EnableIRQ(DMAC_1_IRQn);      // Connect DMAC1 to Nested Vector Interrupt Controller (NVIC)
+
+        // Activate the suspend (SUSP) interrupt on DMAC channel 1
+        DMAC->Channel[1].CHINTENSET.reg = DMAC_CHINTENSET_SUSP;
+
+        // Configure ADC
+        ADC1->INPUTCTRL.bit.MUXPOS = ADC_INPUTCTRL_MUXPOS_AIN12_Val; // Set the analog input to ADC0/AIN2 (PB08 - A4 on Metro M4)
+        while (ADC1->SYNCBUSY.bit.INPUTCTRL)
+            ;                              // Wait for synchronization
+        ADC1->SAMPCTRL.bit.SAMPLEN = 0x00; // Set max Sampling Time Length to half divided ADC clock pulse (2.66us)
+        while (ADC1->SYNCBUSY.bit.SAMPCTRL)
+            ;                                         // Wait for synchronization
+        ADC1->CTRLA.reg = ADC_CTRLA_PRESCALER_DIV128; // Divide Clock ADC GCLK by 128 (48MHz/128 = 375kHz)
+        ADC1->CTRLB.reg = ADC_CTRLB_RESSEL_12BIT |    // Set ADC resolution to 12 bits
+                          ADC_CTRLB_FREERUN;          // Set ADC to free run mode
+        while (ADC1->SYNCBUSY.bit.CTRLB)
+            ;                       // Wait for synchronization
+        ADC1->CTRLA.bit.ENABLE = 1; // Enable the ADC
+        while (ADC1->SYNCBUSY.bit.ENABLE)
+            ;                       // Wait for synchronization
+        ADC1->SWTRIG.bit.START = 1; // Initiate a software trigger to start an ADC conversion
+        while (ADC1->SYNCBUSY.bit.SWTRIG)
+            ; // Wait for synchronization
+
+        // Enable DMA channel 1
+        DMAC->Channel[1].CHCTRLA.bit.ENABLE = 1;
+
+        // Configure Timer/Counter 5
+        GCLK->PCHCTRL[TC5_GCLK_ID].reg = GCLK_PCHCTRL_CHEN |     // Enable perhipheral channel for TC5
+                                         GCLK_PCHCTRL_GEN_GCLK1; // Connect generic clock 0 at 48MHz
+
+        TC5->COUNT16.WAVE.reg = TC_WAVE_WAVEGEN_MFRQ; // Set TC5 to Match Frequency (MFRQ) mode
+        TC5->COUNT16.CC[0].reg = 3000 - 1;            // Set the trigger to 16 kHz: (4Mhz / 16000) - 1
+        while (TC5->COUNT16.SYNCBUSY.bit.CC0)
+            ; // Wait for synchronization
+
+        // Start Timer/Counter 5
+        TC5->COUNT16.CTRLA.bit.ENABLE = 1; // Enable the TC5 timer
+        while (TC5->COUNT16.SYNCBUSY.bit.ENABLE)
+            ; // Wait for synchronization
+    }
+
+    uint16_t _adc_buf_0[ADC_BUF_LEN];
+    uint16_t _adc_buf_1[ADC_BUF_LEN];
+
+    // WAV files have a header. This struct defines that header
+    struct wavFileHeader
+    {
+        char riff[4];         /* "RIFF"                                  */
+        long flength;         /* file length in bytes                    */
+        char wave[4];         /* "WAVE"                                  */
+        char fmt[4];          /* "fmt "                                  */
+        long chunk_size;      /* size of FMT chunk in bytes (usually 16) */
+        short format_tag;     /* 1=PCM, 257=Mu-Law, 258=A-Law, 259=ADPCM */
+        short num_chans;      /* 1=mono, 2=stereo                        */
+        long srate;           /* Sampling rate in samples per second     */
+        long bytes_per_sec;   /* bytes per second = srate*bytes_per_samp */
+        short bytes_per_samp; /* 2=16-bit mono, 4=16-bit stereo          */
+        short bits_per_samp;  /* Number of bits per sample               */
+        char data[4];         /* "data"                                  */
+        long dlength;         /* data length in bytes (filelength - 44)  */
+    };
+
+    void initBufferHeader()
+    {
+        wavFileHeader wavh;
+
+        strncpy(wavh.riff, "RIFF", 4);
+        strncpy(wavh.wave, "WAVE", 4);
+        strncpy(wavh.fmt, "fmt ", 4);
+        strncpy(wavh.data, "data", 4);
+
+        wavh.chunk_size = 16;
+        wavh.format_tag = 1; // PCM
+        wavh.num_chans = 1;  // mono
+        wavh.srate = RATE;
+        wavh.bytes_per_sec = (RATE * 1 * 16 * 1) / 8;
+        wavh.bytes_per_samp = 2;
+        wavh.bits_per_samp = 16;
+        wavh.dlength = RATE * 2 * 1 * 16 / 2;
+        wavh.flength = wavh.dlength + 44;
+
+        _writer.writeSfudBuffer((byte *)&wavh, 44);
+    }
+
+    void audioCallback(uint16_t *buf, uint32_t buf_len)
+    {
+        static uint32_t idx = 44;
+
+        if (_isRecording)
+        {
+            for (uint32_t i = 0; i < buf_len; i++)
+            {
+                int16_t audio_value = ((int16_t)buf[i] - 2048) * 16;
+
+                _writer.writeSfudBuffer(audio_value & 0xFF);
+                _writer.writeSfudBuffer((audio_value >> 8) & 0xFF);
+            }
+
+            idx += buf_len;
+                
+            if (idx >= BUFFER_SIZE)
+            {
+                _writer.flushSfudBuffer();
+                idx = 44;
+                _isRecording = false;
+                _isRecordingReady = true;
+            }
+        }
+    }
+};
+
+Mic mic;
+
+void DMAC_1_Handler()
+{
+    mic.dmaHandler();
+}

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/src/speech_to_text.h

@@ -0,0 +1,102 @@
+#pragma once
+
+#include <Arduino.h>
+#include <ArduinoJson.h>
+#include <HTTPClient.h>
+#include <WiFiClientSecure.h>
+
+#include "config.h"
+#include "flash_stream.h"
+
+class SpeechToText
+{
+public:
+    void init()
+    {
+        _token_client.setCACert(TOKEN_CERTIFICATE);
+        _speech_client.setCACert(SPEECH_CERTIFICATE);
+        _access_token = getAccessToken();
+    }
+
+    String convertSpeechToText()
+    {
+        char url[128];
+        sprintf(url, SPEECH_URL, SPEECH_LOCATION, LANGUAGE);
+
+        HTTPClient httpClient;
+        httpClient.begin(_speech_client, url);
+
+        httpClient.addHeader("Authorization", String("Bearer ") + _access_token);
+        httpClient.addHeader("Content-Type", String("audio/wav; codecs=audio/pcm; samplerate=") + String(RATE));
+        httpClient.addHeader("Accept", "application/json;text/xml");
+
+        Serial.println("Sending speech...");
+
+        FlashStream stream;
+        int httpResponseCode = httpClient.sendRequest("POST", &stream, BUFFER_SIZE);
+
+        Serial.println("Speech sent!");
+
+        String text = "";
+
+        if (httpResponseCode == 200)
+        {
+            String result = httpClient.getString();
+            Serial.println(result);
+
+            DynamicJsonDocument doc(1024);
+            deserializeJson(doc, result.c_str());
+
+            JsonObject obj = doc.as<JsonObject>();
+            text = obj["DisplayText"].as<String>();
+        }
+        else if (httpResponseCode == 401)
+        {
+            Serial.println("Access token expired, trying again with a new token");
+            _access_token = getAccessToken();
+            return convertSpeechToText();
+        }
+        else
+        {
+            Serial.print("Failed to convert text to speech - error ");
+            Serial.println(httpResponseCode);
+        }
+
+        httpClient.end();
+
+        return text;
+    }
+
+private:
+    String getAccessToken()
+    {
+        char url[128];
+        sprintf(url, TOKEN_URL, SPEECH_LOCATION);
+
+        HTTPClient httpClient;
+        httpClient.begin(_token_client, url);
+
+        httpClient.addHeader("Ocp-Apim-Subscription-Key", SPEECH_API_KEY);
+        int httpResultCode = httpClient.POST("{}");
+
+        if (httpResultCode != 200)
+        {
+            Serial.println("Error getting access token, trying again...");
+            delay(10000);
+            return getAccessToken();
+        }
+
+        Serial.println("Got access token.");
+        String result = httpClient.getString();
+
+        httpClient.end();
+
+        return result;
+    }
+
+    WiFiClientSecure _token_client;
+    WiFiClientSecure _speech_client;
+    String _access_token;
+};
+
+SpeechToText speechToText;

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/src/text_to_speech.h

@@ -0,0 +1,86 @@
+#pragma once
+
+#include <Arduino.h>
+#include <ArduinoJson.h>
+#include <HTTPClient.h>
+#include <Seeed_FS.h>
+#include <SD/Seeed_SD.h>
+#include <WiFiClient.h>
+#include <WiFiClientSecure.h>
+
+#include "config.h"
+
+class TextToSpeech
+{
+public:
+    void init()
+    {
+        DynamicJsonDocument doc(1024);
+        doc["language"] = LANGUAGE;
+
+        String body;
+        serializeJson(doc, body);
+
+        HTTPClient httpClient;
+        httpClient.begin(_client, GET_VOICES_FUNCTION_URL);
+
+        int httpResponseCode = httpClient.POST(body);
+
+        if (httpResponseCode == 200)
+        {
+            String result = httpClient.getString();
+            Serial.println(result);
+
+            DynamicJsonDocument doc(1024);
+            deserializeJson(doc, result.c_str());
+
+            JsonArray obj = doc.as<JsonArray>();
+            _voice = obj[0].as<String>();
+
+            Serial.print("Using voice ");
+            Serial.println(_voice);
+        }
+        else
+        {
+            Serial.print("Failed to get voices - error ");
+            Serial.println(httpResponseCode);
+        }
+
+        httpClient.end();
+    }
+
+    void convertTextToSpeech(String text)
+    {
+        DynamicJsonDocument doc(1024);
+        doc["language"] = LANGUAGE;
+        doc["voice"] = _voice;
+        doc["text"] = text;
+
+        String body;
+        serializeJson(doc, body);
+
+        HTTPClient httpClient;
+        httpClient.begin(_client, TEXT_TO_SPEECH_FUNCTION_URL);
+
+        int httpResponseCode = httpClient.POST(body);
+
+        if (httpResponseCode == 200)
+        {            
+            File wav_file = SD.open("SPEECH.WAV", FILE_WRITE);
+            httpClient.writeToStream(&wav_file);
+            wav_file.close();
+        }
+        else
+        {
+            Serial.print("Failed to get speech - error ");
+            Serial.println(httpResponseCode);
+        }
+
+        httpClient.end();
+    }
+private:
+    WiFiClient _client;
+    String _voice;
+};
+
+TextToSpeech textToSpeech;

6-consumer/lessons/3-spoken-feedback/code-spoken-response/wio-terminal/smart-timer/test/README

@@ -0,0 +1,11 @@
+
+This directory is intended for PlatformIO Unit Testing and project tests.
+
+Unit Testing is a software testing method by which individual units of
+source code, sets of one or more MCU program modules together with associated
+control data, usage procedures, and operating procedures, are tested to
+determine whether they are fit for use. Unit testing finds problems early
+in the development cycle.
+
+More information about PlatformIO Unit Testing:
+- https://docs.platformio.org/page/plus/unit-testing.html

6-consumer/lessons/3-spoken-feedback/code-timer/wio-terminal/smart-timer/src/config.h

@@ -16,7 +16,7 @@ const char *LANGUAGE = "<LANGUAGE>";
 const char *TOKEN_URL = "https://%s.api.cognitive.microsoft.com/sts/v1.0/issuetoken";
 const char *SPEECH_URL = "https://%s.stt.speech.microsoft.com/speech/recognition/conversation/cognitiveservices/v1?language=%s";
 
-const char *TEXT_TO_TIMER_FUNCTION_URL = "<URL>";
+const char *TEXT_TO_TIMER_FUNCTION_URL = "http://<IP_ADDRESS>:7071/api/text-to-timer";
 
 const char *TOKEN_CERTIFICATE =
     "-----BEGIN CERTIFICATE-----\r\n"

6-consumer/lessons/3-spoken-feedback/wio-terminal-set-timer.md

@@ -49,13 +49,11 @@ Microcontrollers don't natively have support for multiple threads in Arduino, so
     LanguageUnderstanding languageUnderstanding;
     ```
 
-1. To call your functions app, you need to declare a WiFi client. 
+1. To call your functions app, you need to declare a WiFi client. Add the following to the `private` section of the class:
 
-    * If you are running the function app locally, add the following to the `private` section of the class:
+    ```cpp
-
+    WiFiClient _client;
-        ```cpp
+    ```
-        WiFiClient _client;
-        ```
 
 1. In the `public` section, declare a method called `GetTimerDuration` to call the functions app:
 

6-consumer/lessons/3-spoken-feedback/wio-terminal-text-to-speech.md

@@ -98,7 +98,9 @@ Instead of downloading and decoding this entire list on your microcontroller, yo
 1. Run your function app locally. You can then call this using a tool like curl in the same way that you tested your `text-to-timer` HTTP trigger. Make sure to pass your language as a JSON body:
 
     ```json
-    {"language":"<language>"}
+    {
+        "language":"<language>"
+    }
     ```
 
     Replace `<language>` with your language, such as `en-GB`, or `zh-CN`.
@@ -148,28 +150,11 @@ Instead of downloading and decoding this entire list on your microcontroller, yo
     TextToSpeech textToSpeech;
     ```
 
-1. To call your functions app, you need to declare a WiFi client. The type you need depends on whether you are accessing the function app locally or deployed to the cloud.
+1. To call your functions app, you need to declare a WiFi client. Add the following to the `private` section of the class:
-
-    * If you are running the function app locally, add the following to the `private` section of the class:
-
-        ```cpp
-        WiFiClient _client;
-        ```
-
-    * If you are running the function app in the cloud, add the following to the `private` section of the class:
-
-        ```cpp
-        WiFiClientSecure _client;
-        ```
-
-      You will also need to set the certificate on this class, so add the following constructor to the `public` section:
 
-        ```cpp
+    ```cpp
-        TextToSpeech()
+    WiFiClient _client;
-        {
+    ```
-            _client.setCACert(FUNCTIONS_CERTIFICATE);
-        }
-        ```
 
 1. In the `private` section, add a field for the selected voice:
 
@@ -469,6 +454,12 @@ When needing to manipulate data like this, it is often better to use serverless
     httpClient.end();
     ```
 
+1. The text to be spoken can now be converted to audio. In the `main.cpp` file, add the following line to the end of the `say` function to convert the text to say into audio:
+
+    ```cpp
+    textToSpeech.convertTextToSpeech(text);
+    ```
+
 ### Task - play audio from your Wio Terminal
 
 **Coming soon**

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/include/README

@@ -0,0 +1,39 @@
+
+This directory is intended for project header files.
+
+A header file is a file containing C declarations and macro definitions
+to be shared between several project source files. You request the use of a
+header file in your project source file (C, C++, etc) located in `src` folder
+by including it, with the C preprocessing directive `#include'.
+
+```src/main.c
+
+#include "header.h"
+
+int main (void)
+{
+ ...
+}
+```
+
+Including a header file produces the same results as copying the header file
+into each source file that needs it. Such copying would be time-consuming
+and error-prone. With a header file, the related declarations appear
+in only one place. If they need to be changed, they can be changed in one
+place, and programs that include the header file will automatically use the
+new version when next recompiled. The header file eliminates the labor of
+finding and changing all the copies as well as the risk that a failure to
+find one copy will result in inconsistencies within a program.
+
+In C, the usual convention is to give header files names that end with `.h'.
+It is most portable to use only letters, digits, dashes, and underscores in
+header file names, and at most one dot.
+
+Read more about using header files in official GCC documentation:
+
+* Include Syntax
+* Include Operation
+* Once-Only Headers
+* Computed Includes
+
+https://gcc.gnu.org/onlinedocs/cpp/Header-Files.html

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/lib/README

@@ -0,0 +1,46 @@
+
+This directory is intended for project specific (private) libraries.
+PlatformIO will compile them to static libraries and link into executable file.
+
+The source code of each library should be placed in a an own separate directory
+("lib/your_library_name/[here are source files]").
+
+For example, see a structure of the following two libraries `Foo` and `Bar`:
+
+|--lib
+|  |
+|  |--Bar
+|  |  |--docs
+|  |  |--examples
+|  |  |--src
+|  |     |- Bar.c
+|  |     |- Bar.h
+|  |  |- library.json (optional, custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
+|  |
+|  |--Foo
+|  |  |- Foo.c
+|  |  |- Foo.h
+|  |
+|  |- README --> THIS FILE
+|
+|- platformio.ini
+|--src
+   |- main.c
+
+and a contents of `src/main.c`:
+```
+#include <Foo.h>
+#include <Bar.h>
+
+int main (void)
+{
+  ...
+}
+
+```
+
+PlatformIO Library Dependency Finder will find automatically dependent
+libraries scanning project source files.
+
+More information about PlatformIO Library Dependency Finder
+- https://docs.platformio.org/page/librarymanager/ldf.html

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/platformio.ini

@@ -0,0 +1,23 @@
+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+[env:seeed_wio_terminal]
+platform = atmelsam
+board = seeed_wio_terminal
+framework = arduino
+lib_deps =
+    seeed-studio/Seeed Arduino FS @ 2.1.1
+    seeed-studio/Seeed Arduino SFUD @ 2.0.2
+    seeed-studio/Seeed Arduino rpcWiFi @ 1.0.5
+    seeed-studio/Seeed Arduino rpcUnified @ 2.1.3
+    seeed-studio/Seeed_Arduino_mbedtls @ 3.0.1
+    seeed-studio/Seeed Arduino RTC @ 2.0.0
+    bblanchon/ArduinoJson @ 6.17.3
+    contrem/arduino-timer @ 2.3.0

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/src/config.h

@@ -0,0 +1,95 @@
+#pragma once
+
+#define RATE 16000
+#define SAMPLE_LENGTH_SECONDS 4
+#define SAMPLES RATE * SAMPLE_LENGTH_SECONDS
+#define BUFFER_SIZE (SAMPLES * 2) + 44
+#define ADC_BUF_LEN 1600
+
+const char *SSID = "<SSID>";
+const char *PASSWORD = "<PASSWORD>";
+
+const char *SPEECH_API_KEY = "<API_KEY>";
+const char *SPEECH_LOCATION = "<LOCATION>";
+const char *LANGUAGE = "<LANGUAGE>";
+const char *SERVER_LANGUAGE = "<LANGUAGE>";
+
+const char *TOKEN_URL = "https://%s.api.cognitive.microsoft.com/sts/v1.0/issuetoken";
+const char *SPEECH_URL = "https://%s.stt.speech.microsoft.com/speech/recognition/conversation/cognitiveservices/v1?language=%s";
+
+const char *TEXT_TO_TIMER_FUNCTION_URL = "http://<IP_ADDRESS>:7071/api/text-to-timer";
+const char *GET_VOICES_FUNCTION_URL = "http://<IP_ADDRESS>:7071/api/get-voices";
+const char *TEXT_TO_SPEECH_FUNCTION_URL = "http://<IP_ADDRESS>:7071/api/text-to-speech";
+const char *TRANSLATE_FUNCTION_URL = "http://<IP_ADDRESS>:7071/api/translate-text";
+
+const char *TOKEN_CERTIFICATE =
+    "-----BEGIN CERTIFICATE-----\r\n"
+    "MIIF8zCCBNugAwIBAgIQAueRcfuAIek/4tmDg0xQwDANBgkqhkiG9w0BAQwFADBh\r\n"
+    "MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3\r\n"
+    "d3cuZGlnaWNlcnQuY29tMSAwHgYDVQQDExdEaWdpQ2VydCBHbG9iYWwgUm9vdCBH\r\n"
+    "MjAeFw0yMDA3MjkxMjMwMDBaFw0yNDA2MjcyMzU5NTlaMFkxCzAJBgNVBAYTAlVT\r\n"
+    "MR4wHAYDVQQKExVNaWNyb3NvZnQgQ29ycG9yYXRpb24xKjAoBgNVBAMTIU1pY3Jv\r\n"
+    "c29mdCBBenVyZSBUTFMgSXNzdWluZyBDQSAwNjCCAiIwDQYJKoZIhvcNAQEBBQAD\r\n"
+    "ggIPADCCAgoCggIBALVGARl56bx3KBUSGuPc4H5uoNFkFH4e7pvTCxRi4j/+z+Xb\r\n"
+    "wjEz+5CipDOqjx9/jWjskL5dk7PaQkzItidsAAnDCW1leZBOIi68Lff1bjTeZgMY\r\n"
+    "iwdRd3Y39b/lcGpiuP2d23W95YHkMMT8IlWosYIX0f4kYb62rphyfnAjYb/4Od99\r\n"
+    "ThnhlAxGtfvSbXcBVIKCYfZgqRvV+5lReUnd1aNjRYVzPOoifgSx2fRyy1+pO1Uz\r\n"
+    "aMMNnIOE71bVYW0A1hr19w7kOb0KkJXoALTDDj1ukUEDqQuBfBxReL5mXiu1O7WG\r\n"
+    "0vltg0VZ/SZzctBsdBlx1BkmWYBW261KZgBivrql5ELTKKd8qgtHcLQA5fl6JB0Q\r\n"
+    "gs5XDaWehN86Gps5JW8ArjGtjcWAIP+X8CQaWfaCnuRm6Bk/03PQWhgdi84qwA0s\r\n"
+    "sRfFJwHUPTNSnE8EiGVk2frt0u8PG1pwSQsFuNJfcYIHEv1vOzP7uEOuDydsmCjh\r\n"
+    "lxuoK2n5/2aVR3BMTu+p4+gl8alXoBycyLmj3J/PUgqD8SL5fTCUegGsdia/Sa60\r\n"
+    "N2oV7vQ17wjMN+LXa2rjj/b4ZlZgXVojDmAjDwIRdDUujQu0RVsJqFLMzSIHpp2C\r\n"
+    "Zp7mIoLrySay2YYBu7SiNwL95X6He2kS8eefBBHjzwW/9FxGqry57i71c2cDAgMB\r\n"
+    "AAGjggGtMIIBqTAdBgNVHQ4EFgQU1cFnOsKjnfR3UltZEjgp5lVou6UwHwYDVR0j\r\n"
+    "BBgwFoAUTiJUIBiV5uNu5g/6+rkS7QYXjzkwDgYDVR0PAQH/BAQDAgGGMB0GA1Ud\r\n"
+    "JQQWMBQGCCsGAQUFBwMBBggrBgEFBQcDAjASBgNVHRMBAf8ECDAGAQH/AgEAMHYG\r\n"
+    "CCsGAQUFBwEBBGowaDAkBggrBgEFBQcwAYYYaHR0cDovL29jc3AuZGlnaWNlcnQu\r\n"
+    "Y29tMEAGCCsGAQUFBzAChjRodHRwOi8vY2FjZXJ0cy5kaWdpY2VydC5jb20vRGln\r\n"
+    "aUNlcnRHbG9iYWxSb290RzIuY3J0MHsGA1UdHwR0MHIwN6A1oDOGMWh0dHA6Ly9j\r\n"
+    "cmwzLmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEdsb2JhbFJvb3RHMi5jcmwwN6A1oDOG\r\n"
+    "MWh0dHA6Ly9jcmw0LmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEdsb2JhbFJvb3RHMi5j\r\n"
+    "cmwwHQYDVR0gBBYwFDAIBgZngQwBAgEwCAYGZ4EMAQICMBAGCSsGAQQBgjcVAQQD\r\n"
+    "AgEAMA0GCSqGSIb3DQEBDAUAA4IBAQB2oWc93fB8esci/8esixj++N22meiGDjgF\r\n"
+    "+rA2LUK5IOQOgcUSTGKSqF9lYfAxPjrqPjDCUPHCURv+26ad5P/BYtXtbmtxJWu+\r\n"
+    "cS5BhMDPPeG3oPZwXRHBJFAkY4O4AF7RIAAUW6EzDflUoDHKv83zOiPfYGcpHc9s\r\n"
+    "kxAInCedk7QSgXvMARjjOqdakor21DTmNIUotxo8kHv5hwRlGhBJwps6fEVi1Bt0\r\n"
+    "trpM/3wYxlr473WSPUFZPgP1j519kLpWOJ8z09wxay+Br29irPcBYv0GMXlHqThy\r\n"
+    "8y4m/HyTQeI2IMvMrQnwqPpY+rLIXyviI2vLoI+4xKE4Rn38ZZ8m\r\n"
+    "-----END CERTIFICATE-----\r\n";
+
+const char *SPEECH_CERTIFICATE =
+    "-----BEGIN CERTIFICATE-----\r\n"
+    "MIIF8zCCBNugAwIBAgIQCq+mxcpjxFFB6jvh98dTFzANBgkqhkiG9w0BAQwFADBh\r\n"
+    "MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3\r\n"
+    "d3cuZGlnaWNlcnQuY29tMSAwHgYDVQQDExdEaWdpQ2VydCBHbG9iYWwgUm9vdCBH\r\n"
+    "MjAeFw0yMDA3MjkxMjMwMDBaFw0yNDA2MjcyMzU5NTlaMFkxCzAJBgNVBAYTAlVT\r\n"
+    "MR4wHAYDVQQKExVNaWNyb3NvZnQgQ29ycG9yYXRpb24xKjAoBgNVBAMTIU1pY3Jv\r\n"
+    "c29mdCBBenVyZSBUTFMgSXNzdWluZyBDQSAwMTCCAiIwDQYJKoZIhvcNAQEBBQAD\r\n"
+    "ggIPADCCAgoCggIBAMedcDrkXufP7pxVm1FHLDNA9IjwHaMoaY8arqqZ4Gff4xyr\r\n"
+    "RygnavXL7g12MPAx8Q6Dd9hfBzrfWxkF0Br2wIvlvkzW01naNVSkHp+OS3hL3W6n\r\n"
+    "l/jYvZnVeJXjtsKYcXIf/6WtspcF5awlQ9LZJcjwaH7KoZuK+THpXCMtzD8XNVdm\r\n"
+    "GW/JI0C/7U/E7evXn9XDio8SYkGSM63aLO5BtLCv092+1d4GGBSQYolRq+7Pd1kR\r\n"
+    "EkWBPm0ywZ2Vb8GIS5DLrjelEkBnKCyy3B0yQud9dpVsiUeE7F5sY8Me96WVxQcb\r\n"
+    "OyYdEY/j/9UpDlOG+vA+YgOvBhkKEjiqygVpP8EZoMMijephzg43b5Qi9r5UrvYo\r\n"
+    "o19oR/8pf4HJNDPF0/FJwFVMW8PmCBLGstin3NE1+NeWTkGt0TzpHjgKyfaDP2tO\r\n"
+    "4bCk1G7pP2kDFT7SYfc8xbgCkFQ2UCEXsaH/f5YmpLn4YPiNFCeeIida7xnfTvc4\r\n"
+    "7IxyVccHHq1FzGygOqemrxEETKh8hvDR6eBdrBwmCHVgZrnAqnn93JtGyPLi6+cj\r\n"
+    "WGVGtMZHwzVvX1HvSFG771sskcEjJxiQNQDQRWHEh3NxvNb7kFlAXnVdRkkvhjpR\r\n"
+    "GchFhTAzqmwltdWhWDEyCMKC2x/mSZvZtlZGY+g37Y72qHzidwtyW7rBetZJAgMB\r\n"
+    "AAGjggGtMIIBqTAdBgNVHQ4EFgQUDyBd16FXlduSzyvQx8J3BM5ygHYwHwYDVR0j\r\n"
+    "BBgwFoAUTiJUIBiV5uNu5g/6+rkS7QYXjzkwDgYDVR0PAQH/BAQDAgGGMB0GA1Ud\r\n"
+    "JQQWMBQGCCsGAQUFBwMBBggrBgEFBQcDAjASBgNVHRMBAf8ECDAGAQH/AgEAMHYG\r\n"
+    "CCsGAQUFBwEBBGowaDAkBggrBgEFBQcwAYYYaHR0cDovL29jc3AuZGlnaWNlcnQu\r\n"
+    "Y29tMEAGCCsGAQUFBzAChjRodHRwOi8vY2FjZXJ0cy5kaWdpY2VydC5jb20vRGln\r\n"
+    "aUNlcnRHbG9iYWxSb290RzIuY3J0MHsGA1UdHwR0MHIwN6A1oDOGMWh0dHA6Ly9j\r\n"
+    "cmwzLmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEdsb2JhbFJvb3RHMi5jcmwwN6A1oDOG\r\n"
+    "MWh0dHA6Ly9jcmw0LmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEdsb2JhbFJvb3RHMi5j\r\n"
+    "cmwwHQYDVR0gBBYwFDAIBgZngQwBAgEwCAYGZ4EMAQICMBAGCSsGAQQBgjcVAQQD\r\n"
+    "AgEAMA0GCSqGSIb3DQEBDAUAA4IBAQAlFvNh7QgXVLAZSsNR2XRmIn9iS8OHFCBA\r\n"
+    "WxKJoi8YYQafpMTkMqeuzoL3HWb1pYEipsDkhiMnrpfeYZEA7Lz7yqEEtfgHcEBs\r\n"
+    "K9KcStQGGZRfmWU07hPXHnFz+5gTXqzCE2PBMlRgVUYJiA25mJPXfB00gDvGhtYa\r\n"
+    "+mENwM9Bq1B9YYLyLjRtUz8cyGsdyTIG/bBM/Q9jcV8JGqMU/UjAdh1pFyTnnHEl\r\n"
+    "Y59Npi7F87ZqYYJEHJM2LGD+le8VsHjgeWX2CJQko7klXvcizuZvUEDTjHaQcs2J\r\n"
+    "+kPgfyMIOY1DMJ21NxOJ2xPRC/wAh/hzSBRVtoAnyuxtkZ4VjIOh\r\n"
+    "-----END CERTIFICATE-----\r\n";

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/src/flash_stream.h

@@ -0,0 +1,69 @@
+#pragma once
+
+#include <Arduino.h>
+#include <HTTPClient.h>
+#include <sfud.h>
+
+#include "config.h"
+
+class FlashStream : public Stream
+{
+public:
+    FlashStream()
+    {
+        _pos = 0;
+        _flash_address = 0;
+        _flash = sfud_get_device_table() + 0;
+        
+        populateBuffer();
+    }
+
+    virtual size_t write(uint8_t val)
+    {
+        return 0;
+    }
+
+    virtual int available()
+    {
+        int remaining = BUFFER_SIZE - ((_flash_address - HTTP_TCP_BUFFER_SIZE) + _pos);
+        int bytes_available = min(HTTP_TCP_BUFFER_SIZE, remaining);
+
+        if (bytes_available == 0)
+        {
+            bytes_available = -1;
+        }
+
+        return bytes_available;
+    }
+
+    virtual int read()
+    {
+        int retVal = _buffer[_pos++];
+
+        if (_pos == HTTP_TCP_BUFFER_SIZE)
+        {
+            populateBuffer();
+        }
+
+        return retVal;
+    }
+
+    virtual int peek()
+    {
+        return _buffer[_pos];
+    }
+
+private:
+    void populateBuffer()
+    {
+        sfud_read(_flash, _flash_address, HTTP_TCP_BUFFER_SIZE, _buffer);
+        _flash_address += HTTP_TCP_BUFFER_SIZE;
+        _pos = 0;
+    }
+    
+    size_t _pos;
+    size_t _flash_address;
+    const sfud_flash *_flash;
+
+    byte _buffer[HTTP_TCP_BUFFER_SIZE];
+};

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/src/flash_writer.h

@@ -0,0 +1,60 @@
+#pragma once
+
+#include <Arduino.h>
+#include <sfud.h>
+
+class FlashWriter
+{
+public:
+    void init()
+    {
+        _flash = sfud_get_device_table() + 0;
+        _sfudBufferSize = _flash->chip.erase_gran;
+        _sfudBuffer = new byte[_sfudBufferSize];
+        _sfudBufferPos = 0;
+        _sfudBufferWritePos = 0;
+    }
+
+    void reset()
+    {
+        _sfudBufferPos = 0;
+        _sfudBufferWritePos = 0;
+    }
+
+    void writeSfudBuffer(byte b)
+    {
+        _sfudBuffer[_sfudBufferPos++] = b;
+        if (_sfudBufferPos == _sfudBufferSize)
+        {
+            sfud_erase_write(_flash, _sfudBufferWritePos, _sfudBufferSize, _sfudBuffer);
+            _sfudBufferWritePos += _sfudBufferSize;
+            _sfudBufferPos = 0;
+        }
+    }
+
+    void flushSfudBuffer()
+    {
+        if (_sfudBufferPos > 0)
+        {
+            sfud_erase_write(_flash, _sfudBufferWritePos, _sfudBufferSize, _sfudBuffer);
+            _sfudBufferWritePos += _sfudBufferSize;
+            _sfudBufferPos = 0;
+        }
+    }
+
+    void writeSfudBuffer(byte *b, size_t len)
+    {
+        for (size_t i = 0; i < len; ++i)
+        {
+            writeSfudBuffer(b[i]);
+        }
+    }
+
+private:
+    byte *_sfudBuffer;
+    size_t _sfudBufferSize;
+    size_t _sfudBufferPos;
+    size_t _sfudBufferWritePos;
+
+    const sfud_flash *_flash;
+};

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/src/language_understanding.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <Arduino.h>
+#include <ArduinoJson.h>
+#include <HTTPClient.h>
+#include <WiFiClient.h>
+
+#include "config.h"
+
+class LanguageUnderstanding
+{
+public:
+    int GetTimerDuration(String text)
+    {
+        DynamicJsonDocument doc(1024);
+        doc["text"] = text;
+
+        String body;
+        serializeJson(doc, body);
+
+        HTTPClient httpClient;
+        httpClient.begin(_client, TEXT_TO_TIMER_FUNCTION_URL);
+
+        int httpResponseCode = httpClient.POST(body);
+
+        int seconds = 0;
+        if (httpResponseCode == 200)
+        {
+            String result = httpClient.getString();
+            Serial.println(result);
+
+            DynamicJsonDocument doc(1024);
+            deserializeJson(doc, result.c_str());
+
+            JsonObject obj = doc.as<JsonObject>();
+            seconds = obj["seconds"].as<int>();
+        }
+        else
+        {
+            Serial.print("Failed to understand text - error ");
+            Serial.println(httpResponseCode);
+        }
+
+        httpClient.end();
+
+        return seconds;
+    }
+
+private:
+    WiFiClient _client;
+};
+
+LanguageUnderstanding languageUnderstanding;

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/src/main.cpp

@@ -0,0 +1,133 @@
+#include <Arduino.h>
+#include <arduino-timer.h>
+#include <rpcWiFi.h>
+#include <sfud.h>
+#include <SPI.h>
+
+#include "config.h"
+#include "language_understanding.h"
+#include "mic.h"
+#include "speech_to_text.h"
+#include "text_to_speech.h"
+#include "text_translator.h"
+
+void connectWiFi()
+{
+    while (WiFi.status() != WL_CONNECTED)
+    {
+        Serial.println("Connecting to WiFi..");
+        WiFi.begin(SSID, PASSWORD);
+        delay(500);
+    }
+
+    Serial.println("Connected!");
+}
+
+void setup()
+{
+    Serial.begin(9600);
+
+    while (!Serial)
+        ; // Wait for Serial to be ready
+
+    delay(1000);
+
+    connectWiFi();
+
+    while (!(sfud_init() == SFUD_SUCCESS))
+        ;
+
+    sfud_qspi_fast_read_enable(sfud_get_device(SFUD_W25Q32_DEVICE_INDEX), 2);
+
+    pinMode(WIO_KEY_C, INPUT_PULLUP);
+
+    mic.init();
+
+    speechToText.init();
+    textToSpeech.init();
+
+    Serial.println("Ready.");
+}
+
+auto timer = timer_create_default();
+
+void say(String text)
+{
+    text = textTranslator.translateText(text, SERVER_LANGUAGE, LANGUAGE);
+    Serial.println(text);
+    textToSpeech.convertTextToSpeech(text);
+}
+
+bool timerExpired(void *announcement)
+{
+    say((char *)announcement);
+    return false;
+}
+
+void processAudio()
+{
+    String text = speechToText.convertSpeechToText();
+    text = textTranslator.translateText(text, LANGUAGE, SERVER_LANGUAGE);
+    Serial.println(text);
+
+    int total_seconds = languageUnderstanding.GetTimerDuration(text);
+    if (total_seconds == 0)
+    {
+        return;
+    }
+
+    int minutes = total_seconds / 60;
+    int seconds = total_seconds % 60;
+
+    String begin_message;
+    if (minutes > 0)
+    {
+        begin_message += minutes;
+        begin_message += " minute ";
+    }
+    if (seconds > 0)
+    {
+        begin_message += seconds;
+        begin_message += " second ";
+    }
+
+    begin_message += "timer started.";
+
+    String end_message("Times up on your ");
+    if (minutes > 0)
+    {
+        end_message += minutes;
+        end_message += " minute ";
+    }
+    if (seconds > 0)
+    {
+        end_message += seconds;
+        end_message += " second ";
+    }
+
+    end_message += "timer.";
+
+    say(begin_message);
+
+    timer.in(total_seconds * 1000, timerExpired, (void *)(end_message.c_str()));
+}
+
+void loop()
+{
+    if (digitalRead(WIO_KEY_C) == LOW && !mic.isRecording())
+    {
+        Serial.println("Starting recording...");
+        mic.startRecording();
+    }
+
+    if (!mic.isRecording() && mic.isRecordingReady())
+    {
+        Serial.println("Finished recording");
+
+        processAudio();
+
+        mic.reset();
+    }
+
+    timer.tick();
+}

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/src/mic.h

@@ -0,0 +1,242 @@
+#pragma once
+
+#include <Arduino.h>
+
+#include "config.h"
+#include "flash_writer.h"
+
+class Mic
+{
+public:
+    Mic()
+    {
+        _isRecording = false;
+        _isRecordingReady = false;
+    }
+
+    void startRecording()
+    {
+        _isRecording = true;
+        _isRecordingReady = false;
+    }
+
+    bool isRecording()
+    {
+        return _isRecording;
+    }
+
+    bool isRecordingReady()
+    {
+        return _isRecordingReady;
+    }
+
+    void init()
+    {
+        analogReference(AR_INTERNAL2V23);
+        
+        _writer.init();
+
+        initBufferHeader();
+        configureDmaAdc();
+    }
+
+    void reset()
+    {
+        _isRecordingReady = false;
+        _isRecording = false;
+
+        _writer.reset();
+
+        initBufferHeader();
+    }
+
+    void dmaHandler()
+    {
+        static uint8_t count = 0;
+
+        if (DMAC->Channel[1].CHINTFLAG.bit.SUSP)
+        {
+            DMAC->Channel[1].CHCTRLB.reg = DMAC_CHCTRLB_CMD_RESUME;
+            DMAC->Channel[1].CHINTFLAG.bit.SUSP = 1;
+
+            if (count)
+            {
+                audioCallback(_adc_buf_0, ADC_BUF_LEN);
+            }
+            else
+            {
+                audioCallback(_adc_buf_1, ADC_BUF_LEN);
+            }
+
+            count = (count + 1) % 2;
+        }
+    }
+
+private:
+    volatile bool _isRecording;
+    volatile bool _isRecordingReady;
+    FlashWriter _writer;
+
+typedef struct
+    {
+        uint16_t btctrl;
+        uint16_t btcnt;
+        uint32_t srcaddr;
+        uint32_t dstaddr;
+        uint32_t descaddr;
+    } dmacdescriptor;
+
+    // Globals - DMA and ADC
+    volatile dmacdescriptor _wrb[DMAC_CH_NUM] __attribute__((aligned(16)));
+    dmacdescriptor _descriptor_section[DMAC_CH_NUM] __attribute__((aligned(16)));
+    dmacdescriptor _descriptor __attribute__((aligned(16)));
+
+    void configureDmaAdc()
+    {
+        // Configure DMA to sample from ADC at a regular interval (triggered by timer/counter)
+        DMAC->BASEADDR.reg = (uint32_t)_descriptor_section;                    // Specify the location of the descriptors
+        DMAC->WRBADDR.reg = (uint32_t)_wrb;                                    // Specify the location of the write back descriptors
+        DMAC->CTRL.reg = DMAC_CTRL_DMAENABLE | DMAC_CTRL_LVLEN(0xf);           // Enable the DMAC peripheral
+        DMAC->Channel[1].CHCTRLA.reg = DMAC_CHCTRLA_TRIGSRC(TC5_DMAC_ID_OVF) | // Set DMAC to trigger on TC5 timer overflow
+                                       DMAC_CHCTRLA_TRIGACT_BURST;             // DMAC burst transfer
+
+        _descriptor.descaddr = (uint32_t)&_descriptor_section[1];                    // Set up a circular descriptor
+        _descriptor.srcaddr = (uint32_t)&ADC1->RESULT.reg;                           // Take the result from the ADC0 RESULT register
+        _descriptor.dstaddr = (uint32_t)_adc_buf_0 + sizeof(uint16_t) * ADC_BUF_LEN; // Place it in the adc_buf_0 array
+        _descriptor.btcnt = ADC_BUF_LEN;                                             // Beat count
+        _descriptor.btctrl = DMAC_BTCTRL_BEATSIZE_HWORD |                            // Beat size is HWORD (16-bits)
+                             DMAC_BTCTRL_DSTINC |                                    // Increment the destination address
+                             DMAC_BTCTRL_VALID |                                     // Descriptor is valid
+                             DMAC_BTCTRL_BLOCKACT_SUSPEND;                           // Suspend DMAC channel 0 after block transfer
+        memcpy(&_descriptor_section[0], &_descriptor, sizeof(_descriptor));          // Copy the descriptor to the descriptor section
+
+        _descriptor.descaddr = (uint32_t)&_descriptor_section[0];                    // Set up a circular descriptor
+        _descriptor.srcaddr = (uint32_t)&ADC1->RESULT.reg;                           // Take the result from the ADC0 RESULT register
+        _descriptor.dstaddr = (uint32_t)_adc_buf_1 + sizeof(uint16_t) * ADC_BUF_LEN; // Place it in the adc_buf_1 array
+        _descriptor.btcnt = ADC_BUF_LEN;                                             // Beat count
+        _descriptor.btctrl = DMAC_BTCTRL_BEATSIZE_HWORD |                            // Beat size is HWORD (16-bits)
+                             DMAC_BTCTRL_DSTINC |                                    // Increment the destination address
+                             DMAC_BTCTRL_VALID |                                     // Descriptor is valid
+                             DMAC_BTCTRL_BLOCKACT_SUSPEND;                           // Suspend DMAC channel 0 after block transfer
+        memcpy(&_descriptor_section[1], &_descriptor, sizeof(_descriptor));          // Copy the descriptor to the descriptor section
+
+        // Configure NVIC
+        NVIC_SetPriority(DMAC_1_IRQn, 0); // Set the Nested Vector Interrupt Controller (NVIC) priority for DMAC1 to 0 (highest)
+        NVIC_EnableIRQ(DMAC_1_IRQn);      // Connect DMAC1 to Nested Vector Interrupt Controller (NVIC)
+
+        // Activate the suspend (SUSP) interrupt on DMAC channel 1
+        DMAC->Channel[1].CHINTENSET.reg = DMAC_CHINTENSET_SUSP;
+
+        // Configure ADC
+        ADC1->INPUTCTRL.bit.MUXPOS = ADC_INPUTCTRL_MUXPOS_AIN12_Val; // Set the analog input to ADC0/AIN2 (PB08 - A4 on Metro M4)
+        while (ADC1->SYNCBUSY.bit.INPUTCTRL)
+            ;                              // Wait for synchronization
+        ADC1->SAMPCTRL.bit.SAMPLEN = 0x00; // Set max Sampling Time Length to half divided ADC clock pulse (2.66us)
+        while (ADC1->SYNCBUSY.bit.SAMPCTRL)
+            ;                                         // Wait for synchronization
+        ADC1->CTRLA.reg = ADC_CTRLA_PRESCALER_DIV128; // Divide Clock ADC GCLK by 128 (48MHz/128 = 375kHz)
+        ADC1->CTRLB.reg = ADC_CTRLB_RESSEL_12BIT |    // Set ADC resolution to 12 bits
+                          ADC_CTRLB_FREERUN;          // Set ADC to free run mode
+        while (ADC1->SYNCBUSY.bit.CTRLB)
+            ;                       // Wait for synchronization
+        ADC1->CTRLA.bit.ENABLE = 1; // Enable the ADC
+        while (ADC1->SYNCBUSY.bit.ENABLE)
+            ;                       // Wait for synchronization
+        ADC1->SWTRIG.bit.START = 1; // Initiate a software trigger to start an ADC conversion
+        while (ADC1->SYNCBUSY.bit.SWTRIG)
+            ; // Wait for synchronization
+
+        // Enable DMA channel 1
+        DMAC->Channel[1].CHCTRLA.bit.ENABLE = 1;
+
+        // Configure Timer/Counter 5
+        GCLK->PCHCTRL[TC5_GCLK_ID].reg = GCLK_PCHCTRL_CHEN |     // Enable perhipheral channel for TC5
+                                         GCLK_PCHCTRL_GEN_GCLK1; // Connect generic clock 0 at 48MHz
+
+        TC5->COUNT16.WAVE.reg = TC_WAVE_WAVEGEN_MFRQ; // Set TC5 to Match Frequency (MFRQ) mode
+        TC5->COUNT16.CC[0].reg = 3000 - 1;            // Set the trigger to 16 kHz: (4Mhz / 16000) - 1
+        while (TC5->COUNT16.SYNCBUSY.bit.CC0)
+            ; // Wait for synchronization
+
+        // Start Timer/Counter 5
+        TC5->COUNT16.CTRLA.bit.ENABLE = 1; // Enable the TC5 timer
+        while (TC5->COUNT16.SYNCBUSY.bit.ENABLE)
+            ; // Wait for synchronization
+    }
+
+    uint16_t _adc_buf_0[ADC_BUF_LEN];
+    uint16_t _adc_buf_1[ADC_BUF_LEN];
+
+    // WAV files have a header. This struct defines that header
+    struct wavFileHeader
+    {
+        char riff[4];         /* "RIFF"                                  */
+        long flength;         /* file length in bytes                    */
+        char wave[4];         /* "WAVE"                                  */
+        char fmt[4];          /* "fmt "                                  */
+        long chunk_size;      /* size of FMT chunk in bytes (usually 16) */
+        short format_tag;     /* 1=PCM, 257=Mu-Law, 258=A-Law, 259=ADPCM */
+        short num_chans;      /* 1=mono, 2=stereo                        */
+        long srate;           /* Sampling rate in samples per second     */
+        long bytes_per_sec;   /* bytes per second = srate*bytes_per_samp */
+        short bytes_per_samp; /* 2=16-bit mono, 4=16-bit stereo          */
+        short bits_per_samp;  /* Number of bits per sample               */
+        char data[4];         /* "data"                                  */
+        long dlength;         /* data length in bytes (filelength - 44)  */
+    };
+
+    void initBufferHeader()
+    {
+        wavFileHeader wavh;
+
+        strncpy(wavh.riff, "RIFF", 4);
+        strncpy(wavh.wave, "WAVE", 4);
+        strncpy(wavh.fmt, "fmt ", 4);
+        strncpy(wavh.data, "data", 4);
+
+        wavh.chunk_size = 16;
+        wavh.format_tag = 1; // PCM
+        wavh.num_chans = 1;  // mono
+        wavh.srate = RATE;
+        wavh.bytes_per_sec = (RATE * 1 * 16 * 1) / 8;
+        wavh.bytes_per_samp = 2;
+        wavh.bits_per_samp = 16;
+        wavh.dlength = RATE * 2 * 1 * 16 / 2;
+        wavh.flength = wavh.dlength + 44;
+
+        _writer.writeSfudBuffer((byte *)&wavh, 44);
+    }
+
+    void audioCallback(uint16_t *buf, uint32_t buf_len)
+    {
+        static uint32_t idx = 44;
+
+        if (_isRecording)
+        {
+            for (uint32_t i = 0; i < buf_len; i++)
+            {
+                int16_t audio_value = ((int16_t)buf[i] - 2048) * 16;
+
+                _writer.writeSfudBuffer(audio_value & 0xFF);
+                _writer.writeSfudBuffer((audio_value >> 8) & 0xFF);
+            }
+
+            idx += buf_len;
+                
+            if (idx >= BUFFER_SIZE)
+            {
+                _writer.flushSfudBuffer();
+                idx = 44;
+                _isRecording = false;
+                _isRecordingReady = true;
+            }
+        }
+    }
+};
+
+Mic mic;
+
+void DMAC_1_Handler()
+{
+    mic.dmaHandler();
+}

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/src/speech_to_text.h

@@ -0,0 +1,102 @@
+#pragma once
+
+#include <Arduino.h>
+#include <ArduinoJson.h>
+#include <HTTPClient.h>
+#include <WiFiClientSecure.h>
+
+#include "config.h"
+#include "flash_stream.h"
+
+class SpeechToText
+{
+public:
+    void init()
+    {
+        _token_client.setCACert(TOKEN_CERTIFICATE);
+        _speech_client.setCACert(SPEECH_CERTIFICATE);
+        _access_token = getAccessToken();
+    }
+
+    String convertSpeechToText()
+    {
+        char url[128];
+        sprintf(url, SPEECH_URL, SPEECH_LOCATION, LANGUAGE);
+
+        HTTPClient httpClient;
+        httpClient.begin(_speech_client, url);
+
+        httpClient.addHeader("Authorization", String("Bearer ") + _access_token);
+        httpClient.addHeader("Content-Type", String("audio/wav; codecs=audio/pcm; samplerate=") + String(RATE));
+        httpClient.addHeader("Accept", "application/json;text/xml");
+
+        Serial.println("Sending speech...");
+
+        FlashStream stream;
+        int httpResponseCode = httpClient.sendRequest("POST", &stream, BUFFER_SIZE);
+
+        Serial.println("Speech sent!");
+
+        String text = "";
+
+        if (httpResponseCode == 200)
+        {
+            String result = httpClient.getString();
+            Serial.println(result);
+
+            DynamicJsonDocument doc(1024);
+            deserializeJson(doc, result.c_str());
+
+            JsonObject obj = doc.as<JsonObject>();
+            text = obj["DisplayText"].as<String>();
+        }
+        else if (httpResponseCode == 401)
+        {
+            Serial.println("Access token expired, trying again with a new token");
+            _access_token = getAccessToken();
+            return convertSpeechToText();
+        }
+        else
+        {
+            Serial.print("Failed to convert text to speech - error ");
+            Serial.println(httpResponseCode);
+        }
+
+        httpClient.end();
+
+        return text;
+    }
+
+private:
+    String getAccessToken()
+    {
+        char url[128];
+        sprintf(url, TOKEN_URL, SPEECH_LOCATION);
+
+        HTTPClient httpClient;
+        httpClient.begin(_token_client, url);
+
+        httpClient.addHeader("Ocp-Apim-Subscription-Key", SPEECH_API_KEY);
+        int httpResultCode = httpClient.POST("{}");
+
+        if (httpResultCode != 200)
+        {
+            Serial.println("Error getting access token, trying again...");
+            delay(10000);
+            return getAccessToken();
+        }
+
+        Serial.println("Got access token.");
+        String result = httpClient.getString();
+
+        httpClient.end();
+
+        return result;
+    }
+
+    WiFiClientSecure _token_client;
+    WiFiClientSecure _speech_client;
+    String _access_token;
+};
+
+SpeechToText speechToText;

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/src/text_to_speech.h

@@ -0,0 +1,86 @@
+#pragma once
+
+#include <Arduino.h>
+#include <ArduinoJson.h>
+#include <HTTPClient.h>
+#include <Seeed_FS.h>
+#include <SD/Seeed_SD.h>
+#include <WiFiClient.h>
+#include <WiFiClientSecure.h>
+
+#include "config.h"
+
+class TextToSpeech
+{
+public:
+    void init()
+    {
+        DynamicJsonDocument doc(1024);
+        doc["language"] = LANGUAGE;
+
+        String body;
+        serializeJson(doc, body);
+
+        HTTPClient httpClient;
+        httpClient.begin(_client, GET_VOICES_FUNCTION_URL);
+
+        int httpResponseCode = httpClient.POST(body);
+
+        if (httpResponseCode == 200)
+        {
+            String result = httpClient.getString();
+            Serial.println(result);
+
+            DynamicJsonDocument doc(1024);
+            deserializeJson(doc, result.c_str());
+
+            JsonArray obj = doc.as<JsonArray>();
+            _voice = obj[0].as<String>();
+
+            Serial.print("Using voice ");
+            Serial.println(_voice);
+        }
+        else
+        {
+            Serial.print("Failed to get voices - error ");
+            Serial.println(httpResponseCode);
+        }
+
+        httpClient.end();
+    }
+
+    void convertTextToSpeech(String text)
+    {
+        DynamicJsonDocument doc(1024);
+        doc["language"] = LANGUAGE;
+        doc["voice"] = _voice;
+        doc["text"] = text;
+
+        String body;
+        serializeJson(doc, body);
+
+        HTTPClient httpClient;
+        httpClient.begin(_client, TEXT_TO_SPEECH_FUNCTION_URL);
+
+        int httpResponseCode = httpClient.POST(body);
+
+        if (httpResponseCode == 200)
+        {            
+            File wav_file = SD.open("SPEECH.WAV", FILE_WRITE);
+            httpClient.writeToStream(&wav_file);
+            wav_file.close();
+        }
+        else
+        {
+            Serial.print("Failed to get speech - error ");
+            Serial.println(httpResponseCode);
+        }
+
+        httpClient.end();
+    }
+private:
+    WiFiClient _client;
+    String _voice;
+};
+
+TextToSpeech textToSpeech;

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/src/text_translator.h

@@ -0,0 +1,58 @@
+#pragma once
+
+#include <Arduino.h>
+#include <ArduinoJson.h>
+#include <HTTPClient.h>
+#include <WiFiClient.h>
+
+#include "config.h"
+
+class TextTranslator
+{
+public:
+    String translateText(String text, String from_language, String to_language)
+    {
+        DynamicJsonDocument doc(1024);
+        doc["text"] = text;
+        doc["from_language"] = from_language;
+        doc["to_language"] = to_language;
+
+        String body;
+        serializeJson(doc, body);
+
+        Serial.print("Translating ");
+        Serial.print(text);
+        Serial.print(" from ");
+        Serial.print(from_language);
+        Serial.print(" to ");
+        Serial.println(to_language);
+
+        HTTPClient httpClient;
+        httpClient.begin(_client, TRANSLATE_FUNCTION_URL);
+
+        int httpResponseCode = httpClient.POST(body);
+
+        String translated_text = "";
+
+        if (httpResponseCode == 200)
+        {
+            translated_text = httpClient.getString();
+            Serial.print("Translated: ");
+            Serial.println(translated_text);
+        }
+        else
+        {
+            Serial.print("Failed to translate text - error ");
+            Serial.println(httpResponseCode);
+        }
+
+        httpClient.end();
+
+        return translated_text;
+    }
+
+private:
+    WiFiClient _client;
+};
+
+TextTranslator textTranslator;

6-consumer/lessons/4-multiple-language-support/code/wio-terminal/smart-timer/test/README

@@ -0,0 +1,11 @@
+
+This directory is intended for PlatformIO Unit Testing and project tests.
+
+Unit Testing is a software testing method by which individual units of
+source code, sets of one or more MCU program modules together with associated
+control data, usage procedures, and operating procedures, are tested to
+determine whether they are fit for use. Unit testing finds problems early
+in the development cycle.
+
+More information about PlatformIO Unit Testing:
+- https://docs.platformio.org/page/plus/unit-testing.html