LED Alpha-display (Serial)



Ok, there are a lot of LCDs around using the standard driver IC, I wanted something a little brighter. Backlighting didnt do it for me so I built this. Using 4 LED displays, each with 4 digits and a pic to control them all I built a replacement for the standard 1line 16char lcd.


It was quite hard to make up a 2 layer PCB, but as the displays use a parallel interface there were so many connections it was needed. An RS232 driver is onboard so standard Serial can be used, the PIC translates it and displays the text on the LED display. The small 3 pin header is for power, regulated 5v. I tend to take this from a spare USB port.
I guess it would have been better to put a USB to serial IC onboard and have the whole thing USB powered, but I wanted to be able to connect any serial device rather than just USB to a PC.

The PCB was made by printing the design onto transparency and doing UV exposure on a double sided copper board. Standard chemical etching. Trust me when I say its a PAIN to line up the two sides so the through holes meet each other!

A pic 16f84 with 4mghz ceramic resonator does all the work with the help of a serial to parallel convertor to get enough IO for all 4 displays.
The displays (four of them) were labelled DL1414, it wasn’t too hard to dig up info on them. They were salvaged parts and as such I do not know how to source more. However I now have a LOAD of better ones, 8 character dot matrix 5*7 LED displays! Im working on a design now.

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