Until recently, I was keeping track of my body weight with an excel sheet, manually writing down the readings of my scale on a new cell each time. Those times are over: My scale now does it automatically for me.
I took apart my scale and removed all of its electronics apart from its load cells and replaced them with an HX711 load cell amplifier, Wemos D1 mini (ESP8266 breakout board) and SSD1306 OLED display. With this setup, the ESP8266 reads measurements from the load cells, converts it into the appropriate value in kilograms and sends it via rest API call using Wi-Fi to a server of my choice. I designed a simple Node.js app to respond to those API calls, store the measurements in a MongoDB colleaction and display them on a webpage.
Note: The video was taken a while ago and the scale was uploading results to thingspeak instead of the Node.js app
The source code for thefirmware running on the scale is available on GitHub here. It relies on the following libraries: