This application uses a Raspberry Pico, potmeter (or other analog input), and HT16K33 7-segment display to display the current time. The application is written in C++ and uses the pico_sdk as it's only dependency. You will also need the compiler for the Raspberry Pico. You can read how you can install this here.

The Analog input must be connected to gpio 28, ADC_VREF, and ADC_GND. The HT16K33 must be connected to the default I2C pins (SDA to GPIO4, SCL to GPIO5), 3V3, and a GND of the Raspberry Pico.

Can run for more than 2 days on a small powerbank.