“This is my multiple-category project/productivity timer with RGB keys (real keyboard switches and keycaps!) and a colorful RGB backlit LCD.
It’s a device I couldn’t buy for any price.
I’ve tried software timers (and have made several) for desktop and phones. But when tasks start switching quickly (exactly when I want to track them the most), it’s always been too much of a hassle to operate a software timer. I really wanted to be able to hit a single key to switch timer categories.
My device is perhaps extreme overkill, but didn’t really cost all that much to make. It could have been made much cheaper. I happily paid more for components that were intended to make life easier for hobby-level makers such as myself. Almost all hardware communication uses the 2-wire I2C protocol. The keypad and LCD both come with their own microcontrollers to facilitate this, which means this timer actually has at least three computers onboard.
Hardware components
Off-the-shelf hardware:
Raspberry Pi Pico microcontroller (RP2040 32-bit dual ARM Cortex-M0+)
Adafruit NeoKey 1x4 QT I2C Breakout (Cherry-compatible keypad + NeoPixels)
SparkFun SerLCD (RGB 16x2 LCD + AVR microcontroller with I2C, etc.)
Qwiic (Sparkfun) aka STEMMA QT (Adafruit) 4 Pin JST SH connector mini-breakout”