IoT-For-Beginners/6-consumer/lessons/3-spoken-feedback

Set a timer and provide spoken feedback

Add a sketchnote if possible/appropriate

Pre-lecture quiz

Pre-lecture quiz

Introduction

Smart assistants are not one-way communication devices. You speak to them, and they respond:

"Alexa, set a 3 minute timer"

"Ok, your timer is set for 3 minutes"

In the last 2 lessons you learned how to take speech and create text, then extract a set timer request from that text. In this lesson you will learn how to set the timer on the IoT device, responding to the user with spoken words confirming their timer, and alerting them when their timer is finished.

In this lesson we'll cover:

• Text to speech
• Set the timer
• Convert text to speech

Text to speech

Set the timer

The timer can be set by sending a command from the serverless code, instructing the IoT device to set the timer. This command will contain the time in seconds till the timer needs to go off.

Task - set the timer using a command

1. In your serverless code, add code to send a direct method request to your IoT device

   ⚠️ You can refer to the instructions for sending direct method requests in lesson 5 of the farm project if needed.

   You will need to set up the connection string for the IoT Hub with the service policy (NOT the device) in your local.settings.json file and add the azure-iot-hub pip package to your requirements.txt file. The device ID can be extracted from the event.

2. The direct method you send needs to be called set-timer, and will need to send the length of the timer as a JSON property called time. Use the following code to build the CloudToDeviceMethod using the total_time calculated from the data extracted by LUIS:

   payload = {
       'time': total_time
   }
   direct_method = CloudToDeviceMethod(method_name='set-timer', payload=json.dumps(payload))
   

💁 You can find this code in the code-command/functions folder.

Task - respond to the command on the IoT device

1. On your IoT device, respond to the command.

   ⚠️ You can refer to the instructions for handling direct method requests from IoT devices in lesson 4 of the farm project if needed.

2. Work through the relevant guide to set a timer for the required time:

• Arduino - Wio Terminal
• Single-board computer - Raspberry Pi/Virtual IoT device

💁 You can find this code in the code-command/wio-terminal, code-command/virtual-device, or code-command/pi folder.

Convert text to speech

The same speech service you used to convert speech to text can be used to convert text back into speech, and this can be played through a microphone on your IoT device.

Task - convert text to speech

Work through the relevant guide to convert text to speech using your IoT device:

• Arduino - Wio Terminal
• Single-board computer - Raspberry Pi
• Single-board computer - Virtual device

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🚀 Challenge

Post-lecture quiz

Post-lecture quiz

Review & Self Study

Assignment