My first go at creating a simple battery powered temperature sensor was really interesting and fun to do, but, like any project, there are always way to make it better!
For my Mark II sensor, there were a few things I wanted to improve:
- Use of mesh networking – Wifi Mesh or Bluetooth mesh
- Capture more data (humidity)
- Support MQTT discovery in Hass.io
- Longer batter life
- Better housing of the electronics
- Custom PCB to mount the components
- Low battery notifications
I’m interesting in exploring the concept of mesh networking. Within the Expressif family of devices, there are two flavors that I’m aware of; WiFi mesh and Bluetooth Low Energy Mesh. The ESP32 platform supports both of these. My current Temperature Sensor is built upon the ESP8266, but moving to the ESP32 should be straight forward.
In Progress – .
Mk I of my sensor was a simple temperature probe. I wanted to expand on this after I found the Bosch BME280 sensor. This little sensor can capture temperature, pressure and humidity. The boards I ordered work on the I2C protocol, so I’ll have to figure that out.
I use the Hass.io platform to manage my automation at home. It supports a simple MQTT interface for receiving data and sending commands. Typically, you would configure the devices within a config file, but it does support a discovery protocol, which allows devices to make themselves known to Hass and to provide all the information required for Hass to use them.
I would like my temperature sensors to support this mode, so that when they fire themselves up for the first time, they would register themselves automatically.
I’d like to enclose my sensor in a nice case, so that I can mount them on the wall in way that doesn’t look completely ugly!
Low battery notifications