Thinger Smart Plug ESP32

Thingler Smart Plug ESP32 is the software controlling the ESP32 microcontroller for a smart plug device. The software is written in C and using the esp-idf library. The microcontroller will connect with AWS IoT and the functionallty of the smart plug can be controlled with help of the AWS IoT service.

Getting started

Requirements

• ESP32 development, for example Thingler ESP32-PICO-D4 Module

• Follow Espressif Systems Getting started instructions to install esp-idf library

• Amazon Web Services (AWS) account

Configure AWS IoT

• Sign into your AWS account

• Select the region you want to work in, e.g. N. Virginia (us-east-1) from the right side on the top menu

• Click in Services in the top meny and select IoT Core

• Create a new thing from Manage --> Things --> Register a thing

• Create a single thing

• Give a name an hit next

• Click on "create certificate"

• Save all certificates including the root CA for AWS IoT and hit activate

• Click Done

• Click on your new thing --> interact and copy the HTTPS rest API enpoint (e.g. someid-ats.iot.us-east-1.amazonaws.com) and store it for later

• From the left hand meny click Secure --> Polices --> Create policy

• Name the policy, enter iot:* for the action field, * for Resource ARN, select the Allow checkbox and hit Create

• Attach the policy to the certificate from Secure --> Certificates, click the three dots on the certificate and select Attatch policy. Select the newly created policy and hit attach

Configure ESP32

Start by cloning the project with submodules

git clone --recurse-submodules https://github.com/thingler/smart-plug-esp32.git

Next copy the certificates that was saved from the AWS console into the directory, smart-plug-esp32/main/certs. The certificates has to be named, aws-root-ca.pem, certificate.pem.crt and private.pem.key.

Compile

Now the software is ready to be compiled. Make sure that the ESP-IDF tools variables has been exported with:

. $HOME/esp/esp-idf/export.sh

Now it is possible to configure the application with:

idf.py menuconfig

• Select Thingler Smart Plug Configuration and edit the values for WiFi SSID and WiFi Password

• Select Component config --> Amazon Web Services IoT Platform and edit the value for AWS IoT Endpoint Hostname. Use the enpoint that was copied in the steps for configuring AWS IoT.

• Hit S for saving the configuration and hit Q for exiting the configurations

Now compile the software with the following command

idf.py build

Flash ESP32

The last step is to flash the software to the ESP32 Module. Connect your ESP32 programmer and flash the software with the following command

idf.py flash

It's also possible to read the serial communication from the ESP32 microcontroller with

idf.py flash monitor

Test ESP32

The easiest way to test the communication between AWS IoT and the ESP32 microcontroller is to

• Sign into your AWS account

• Click in Services in the top meny and select IoT Core

• Click Test from the left hand menu

• Fill in smart/plug in the subscription topic filed and click "Subscribe to topic"

• Power up ESP32. The message "Thing is connected" should appear after a short while in the test window on AWS.

• The defined GPIO_SWITCH pin in the software can be turned on by writing on in the test window and hit "Publish to topic"

• The same pin can be turned off by writing off and publishing it to the topic

License

Released under GNU/GPL Version 3