coffee-scales

Kitchen scales, built for drip coffee brewing:

• 0.1 gram precision
• Very quick response
• Very quick tare
• Auto-starting brew timer
• Auto-off after 5 minutes

Current prototype looks something like this:

Firmware

Setup:

1. Install PlatformIO Core and shell commands
2. Install Just

Usage:

cd firmware
just --list

to list all recipes.

Hardware

• Adafruit Feather 328P
• Load cell: 1 kg straight bar
• HX711 load cell amplifier
• Two 4-digit 7-segment displays with TM1637 drivers
• LiPo battery (1200 mAh)
• Push button for taring

Development and debugging

Log raw data to CSV with the logging recipe. Then process the data with firmware/logs/process.m. Look at the processed CSV in e.g. PlotJuggler.

Here's the state diagram: