POE BaseStation

Base station for connecting remote sensors to Thingsboard.

Remote sensors use PJON over LoRa radio to communicate. The Thingsboard Gateway MQTT API is used to connect on the Thingsboard side.

See here for other sensors and more information on the system.

Written by Jotham Gates August 2023

Photos

Getting started

The Github repository containing all design files and code is here.

1. Install Platform IO.
2. Open the project in the BaseStationCode directory.
3. Create a copy of BaseStationCode/credentials.example.ini and name this credentials.ini. Fill out the settings in this file for the WiFi network to connect to, MQTT broker, Thingsboard credentials and Over The Air (OTA) update settings.
4. Upload the code to the ESP32.
5. Assemble the electronics as shown in the schematics and optionally place inside a case.
6. Test with other sensors and the Thingsboard server.

Updating using OTA updates

Over the air (OTA) updates can be used to update the software on the base station once it has been programmed for the first time. To do this:

1. Edit the upload port and auth flags in credentials.ini to match those currently set on the device.
2. Change the active Platform IO environment to Tardis-OTA from its default Tardis environment (likewise for the TVAnt environemnt for ethernet).
3. Compile and upload code as normal.

Schematics

The base station uses an ESP32 development board as its base. An SX1278 LoRa radio module breakout board is connected via jumper leads. LEDs are soldered along with their respective current limiting resistors to wires that can be plugged into the ESP32 board. An audio amplifier and speaker can also be connected for alarm functionality. I salvaged this from the sound effects module of a broken children's ride on toy car.

Fun part / experiments

I originally planned to use the build in DAC of the ESP32 to play sounds on alarm conditions. At this point I haven't succeded in this (currently using the TunePlayer library to play simple monotonic songs instead). I did come across the ESP32-A2DP library that allows the use of this unit as a terrible sounding bluetooth speaker.

This sketch is the bt_music_receiver_to_internal_dac example from the ESP32-A2DP library with the addition of flashing lights.