ESP32 with WiFi and BLE
This circuit will serve as the communication circuit using the ESP32, a microcontroller with WiFi and BLE (Bluetooth Low Energy) capabilities. This circuit will send all sensor data to the IoT platform or the MQTT broker over WiFi and to the mobile app over BLE. It will receive control signals from the mobile app over BLE and remotely via MQTT over WiFi.
The ESP32 circuit will exchange data with the Nano 1 and Pico circuits over UART and with the Nano 2 circuit over LoRa.
In this step we will add the OLED display and the LED module.
See the OLED physical-computing guide.
We will pick this circuit up again later and update the program to enable data exchange with the MQTT Broker over WiFi and data exchange with the IoT App over BLE.
In the Node-RED variant of the solution the Nano and Pico circuits will be directly connected with USB cables to the computer running Node-RED which will exchange data with the MQTT broker. In this scenario, the ESP32 circuit is not required. However, if the ESP32 circuit is not included, the Node-RED variant will also not support BLE communication with the mobile app.