ESP32 - Azure IoT Device with OTA

This project aims to demonstrate how we can use ESP32 with Azure IoT Hub and implement OTA features through the platform.

Prerequisites

To work with this library, you will have to follow some prerequisites sets that are described at the wiki: https://github.com/kbeaugrand/ESP32_AzureIoT_OTA/wiki.

Getting Started

Install this repository as an Arduino Library

In this section, you install this repository as an Arduino Library on your computer.

1. Download the library from the releases on github: https://github.com/kbeaugrand/ESP32_AzureIoT_OTA/releases

2. Extract the release to Arduino Library (see: https://www.arduino.cc/en/Guide/Libraries#manual-installation)

Configure the device settings

In this section you create a new sketch called "Device Initiator" that helps you to configure the device settings. This sketch will create a new partition scheme on the device storage, and create the device settings file on that storage.

Note

Storing those settings enables the possibility to work with Firmware update Over The Air without storing the device identity with the Firmware.

1. Start a new sketch from an example

   • Open VS Code and press F1 or Ctrl + Shift + P to open command palette
   • Select Ardiuno: Examples command
   • On Arduino Examples Window, select Examples from Custom Libraries > ESP32_AzureIoT_OTA > ESP32_Device_Initiator

2. Configure your ESP 32 board from VSCode

   • Open VS Code and press F1 or Ctrl + Shift + P to open command palette
   • Select Ardiuno: Board Config command
   • On Arduino Board Configuration Window select the Minimal SPIFFS Partition Scheme

3. On ESP32_Device_Initiator, type your device connection settings

   const char *connectionString = "Type your Device Connection String";
   const char *ssid = "Type here your WiFi SSID";
   const char *password = "Type here your WiFi shared Key";

4. Upload this sketch to Arduino ESP32

   • Alt + Cmd + U or Alt + Ctrl + U

Note

Once this sketch is uploaded on the ESP 32, the integrated LED will be high.

Create the device Firmware

In this section, you create the device firmware code.

1. Start a new sketch from an example

   • Open VS Code and press F1 or Ctrl + Shift + P to open command palette
   • Select Ardiuno: Examples command
   • On Arduino Examples Window, select Examples from Custom Libraries > ESP32_AzureIoT_OTA > ESP32_Device_OTA

2. Configure your ESP 32 board from VSCode

   • Open VS Code and press F1 or Ctrl + Shift + P to open command palette
   • Select Ardiuno: Board Config command
   • On Arduino Board Configuration Window select the Minimal SPIFFS Partition Scheme

   [!NOTE] This sketch will use the device settings file previously created to get its credentials and connect to WiFi and IoT Hub. You will have to update the device logic on this one.

3. Configure the Arduino build output for this sketch

   • Open the .vscode/arduino.json

   • Update the settings file with this line:

     {
         "output": "./.build"
     }

4. Upload this sketch to Arduino ESP32

   • Alt + Cmd + U or Alt + Ctrl + U

Upload the device firmware to a Cloud Storage

In this section, you create a cloud storage account and upload you device firmware to it.

Build the firmware binary

1. Open the sketch repository with VS Code

2. Update the FIRMWARE_VERSION

   #define FIRMWARE_VERSION "0.0.2"

3. Build the firmware

   • Alt + Cmd + R or Alt + Ctrl + R

Upload the binary to your storage account container

1. Navigate to your new storage account container in the Azure portal.
2. Select the Upload button.
3. Click on the Select file button.
4. On the OpenWindow, select the firmware binary from the sketch build directory ./.build/.The default name is ESP32_Device_OTA.ino.bin.

Create a Firmware update OTA with device Twin

In this section, you update your device twin to set a firmware update from the cloud portal.

1. In your IoT hub navigation menu, open IoT Devices, then select the IoT device you created.

2. Select the Device Twin button.

3. Use the twin editor to update your device twin with this following statements

   {
   "properties": {
       "desired": {
         "firmware": {
           "version": "0.0.2",
           "source": "https://<storage_account_name>.blob.core.windows.net/<container_name>/ESP32_Device_OTA.ino.bin"
         }
       }
   }

4. Select the Save button.

5. Select the Refresh button to review the reported properties and verify once the device successfully applied the firmware update

   {
       "properties": {
           "reported": {
             "firmware": {
               "version": "0.0.2"
             }
       }
   }

Note

On device Serial Monitor, you may see the device update done Open VS Code and press F1 or Ctrl + Shift + P to open command palette Select Arduino: Open Serial Monitor command

> Debug: Begin request for: https://<storage_account_name>.blob.core.windows.net/<container_name>/ESP32_Device_OTA.ino.bin
> Debug: Trying to start OTA with 1040864 bytes
> Info: Begin OTA. This may take 2 - 5 mins to complete. Things might be quite for a while.. Patience!
> Info: Written: 1040864 successfully
> Info: OTA done!
> Info: Update successfully completed. Rebooting.