Pseudonymous maker "keatonatron" has put together a Wi-Fi-connected desk thermometer with a difference: its components are left on display, mounted in a transparent housing for all to see.
"I couldn't find a Wi-Fi thermometer with the features I wanted, so I made my own! The design concept was 'exposed components mounted in glass,'" keatonatron explains of their creation. "I designed three layers of laser-cut acrylic panels that are tinted to look like glass. The middle layer [has] cut-outs for the wires and components. At night the whole thing glows green, due to the power LED on the back of the display."
The heart of the system is an Adafruit QT Py ESP32-C3 development board, built for a small footprint while still including a USB Type-C connector for data and power. A temperature sensor breakout provides live readings through a window cut in the front acrylic panel, which is read out on a pair of three-digit seven-segment displays — as well as being reported over the ESP32's Wi-Fi radio.
"I built my own 'smart thermostat,' which consists of a Wi-Fi-controlled relay that can turn my heating on and off as needed. So, I also need to know the temperature in the room to decide if the heat needs to go on or off," keatonatron explains. "I'm using Tasmota to control all of the Wi-Fi chips. Both devices use MQTT to talk to a server running Home Assistant, which receives the temperature, uses the logic I've specified to determine if the heat needs to be on or not, and sends a command to the heat controller."
"The other products I already purchased and tried out would only report once the temp changed a certain amount and/or five minutes had passed," keatonatron continues. "I now have the value reported once per minute, even if it hasn't changed. Pretty sure I could increase the resolution as well (but I'm sticking with one decimal place for now)."
More information on the build is available on keatonatron's Reddit post.