I have added a disclaimer page, see the pages section on the right to view.
Don’t worry folks, I haven’t left the z80 camp and joined the CNC/Fabber camp. I know there haven’t been any z80 updates in … uh a long time but I promise they will come. The building of the CNC machine is a long way off (few months to years) anyhow. I think as soon as I can get a mostly working design in my head, I’ll put the CNC Machine down and get to work on other things. Hopefully I can take some pictures of the LCD Tester and get back to work on it. I’ll try to keep the updates more regular.
Hi,
Take a look at this site. You may find it of interest.
http://homepages.tesco.net/~steve.lawther/steve/charlcd.htm
This code simply checks an LCD and wiring is working correctly, and indicates on an LED what faults were found. Tests any character LCD display based on the HD44780 or compatible controller.
Compatibles believed to be, but not tested:-
* Samsung KS0066
* Sanyo LC7985 NA
* Epson SED1278
* UMC UM3881B
* OKI MSM6222
* Toshiba T7934-0000 (has extra characters in CG ROM )
* NewJapanRadio NJU64xx (various)
Indications repeated every 4 seconds :-
* constantly on or off – PIC not running, or not programmed correctly, or LED not wired up correctly
* 1 x 1/2 sec flash – all GOOD – LCD working correctly.
(if display not readable, alter contrast)
* 2 x 1/2 sec flashes – Pins shorted / wired wrong.
(After setting the signals to the LCD, they read back differently)
* 3 x 1/2 sec flashes – LCD busy too long or no display attached.
(After waiting long enough for an LCD instruction to have finished, the busy flag still reads as busy)
* 4 x 1/2 sec flashes – address readback incorrect – check data wiring.
(After setting LCD to auto increment character address, read back character address is different to that expected)
When correctly connected, and contrast set correctly, part of the character set will be displayed on the LCD.
Comment by Brian — November 25, 2007 @ 7:20 pm
Hi Brian,
Thank you for taking the time to leave a comment, I appreciate it. That is indeed of interest to me. Using this code could very well make interfacing a LCD panel to a uP much easier. When I get around to building my microprocessor system, I will definitely use this code with it. Thanks for bringing to my attention.
Comment by Toad — November 26, 2007 @ 12:22 am