32205Project: Low-Cost Hex Displays
- Aug 28, 2013I've been working on actually finishing a project I started three years ago: creating a Microchip PIC based display driver for displaying hex digits on multiplexed 7-segment LED displays. Here's my progress so far:
I acquired a large quantity of the bubble-magnified displays seen above by accident -- bought what I thought was a lot of 20, but it was a lot of /20 bags of 10/, plus some loose displays! I thought they would make a nice retro-looking alternative to expensive/harder-to-get smart displays like the TIL311. They also draw a /lot/ less current -- 100 mA with all segments on for 8 characters.
Anyway, the prototype seems to work well! It will take data as 24 parallel bits and display six hex characters. The display is fully driven so the blanks are just 0x00 in the display buffer. Since it's implemented with a bitmapped buffer, it's possible to alter the firmware to take input from other devices on the PIC (i2c, SPI, parallel slave port, RS-232, et c.).
I'm currently assessing interest in a run of PC boards for this project. Point-to-point wiring fills my needs, but I'd imagine that other hobbyists are interested in cheap hex displays too!
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