How to build an interactive device with 4 panel display and basic add/subtract function for counting

Thread Starter


Joined Dec 7, 2017
I just wanted to know the feasibility of making this basic device. Would just want the device to count up and down by pressing the arrows on either side of the device. Would want the device to be about 2"x2" or 2"x3" and encased in flexible plastic so it could have some bend. Can I have the separate display panels so both sides can count up to 99? At the bottom center I would want a reset button that would resent all panels to zeros, is that possible? My knowledge of circuitry and programming is limited and I wanted to know how complicated it would be to make something like this. Any help would be appreciated. device.png


Joined Aug 1, 2013
In terms of parts count and assembly effort, the simplest approach is a small microcontroller (uC) like a PIC. If you don't need exceptional brightness, the PIC can drive the displays directly, accept all 5 switch inputs, fold your laundry, etc. BUT, you're looking at a couple of weeks of program, debug, and test effort for a pro, longer for an amateur, much longer if this is your first uC project. And you need a development system.

Separate from that, this can be done in all hardware (counters, gates, display drivers - chips). The body count is a bit high because I think the up/down requirement limits you to only one digit's counting per chip.
4 - BCD up/down counters
4 - display decoder/drivers
4 - debounce circuits (Rs and Cs, no chips) (the reset switch does not need to be debounced)