Little LCD tester

April 2nd, 2011 | Categories: Electronics | Tags: , , ,

Well, after some playing around and getting my electronics feet back, I’ve finally rediscovered some passion. This little project is something I’ve wanted to do for quite some time. Basically it’s an HD44780 LCD tester. A very simple device but if you’re like me, when you receive an LCD in the mail, you want to be able to see the device in it’s glory.

The board inside the LCD tester

The board inside the LCD tester

I just made it with a PIC16F690 MCU and some random components. The output is of course the LCD but also two LEDs. The unit has provisions for the backlight though it’s just straight 5v out, you have to worry about resistances when you hook it up.

The button on the back of the unit basically prints extra 20 character long strings so you can see how the memory is addressed and see how things scroll over in printing.

Anyways, here are pics:

Finished unit from the back

Finished unit from the back. 5v barrel connector and a toggle switch for power

The unit from the front

The unit from the front. just the LEDs and the pinouts. Also note the knob on the top for the pot. that's for adjusting contrast.

The text out

The text out. this one on a 2004 lcd

Well, there we go. This will be a handy little device for testing whether any of them are any good.

  1. Ron
    December 20th, 2011 at 06:18
    Reply | Quote | #1


    I’ve been looking for something like this..Can you share the schematic/codes etc…and is it possible to used other PIC devices like 16F84 or 16F628A?


  2. smackaay
    December 21st, 2011 at 15:11
    Reply | Quote | #2

    I don’t have the schematics since I just put it together from my head but I may make a new one for shits and giggles and make some easy to read instructions. You can use pretty much any PIC 14 pin and over. 7 IO are for the LCD. 2 IO for the LED. and one for the button. so 10 usable IO are required. Also, you may need a bit of ROM and RAM space so a pic16f550 may be insufficient.

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