This application required more flexibility than the LM3914 offers, and it uses a circuit based on an Atmel AVR-family ATTiny13 microcontroller, which features 1 kbyte of program memory; a four-channel ...
[Oleg] found himself in possession of a Stamps.com Model 510 5lb digital scale. It’s a great scale, but only works as a USB HID device. In other words, it’s a digital scale without a digital display.