HT1632 LED matrix driver

This article covers how to connect HT1632 LED driver to Carambola using only it's own peripherals and how to display real-time clock.

I have used my own custom made board to drive LED's, but there are some popular options in ebay (just enter "HT1632") if you do not wish to make PCB's and solder (though code will drive circuit, but you have to adjust a bit). In my case it was a bit challenging because of small (2x2cm) LED matrix. Anyway, there is schematics.

I did not created source code from scratch, instead modified this one. Modified source code can be found here. Full sources as Carambola package will be released soon. Full sources as a package can be found here

I have mapped pins to Carambola like this:

• GPIO9 → CS
• GPIO7 → WR
• GPIO13 → DATA

Just add

* * * * * /usr/sbin/led_matrix_test

to crontab and once a minute you have updated time on your display.