Some ugly C code to capture different measures (like: timestamp, input voltage, iteration, scale reading, ...), store up to a few kB of them in ESP8266 memory, and then flush periodically to an SD card.
The data collector consists of:
- microcontroller - ESP8266 - had lying it around & needed internet based timestamp for post processing
- ADS1115 - 4channel, 16bit ADC to read reference voltages
- BME280 - I2C/SPI temperature, humidity, pressure sensor
- SD card - to store captured data
- [optionally] small fan to distribute heat evenly in the environment
- [optionally] designated reference voltage for cell sensor ADC
- [variation of] different power supplies
- [variation of] different ADC sensors (HX711, NAU7802)
- shoe box with a lid, some wood, and a bunch of wires
For more details go to: Researching weight scales - hardware and firmware.