Tech^Cellfish

My LCD is a Shelly 41602THB-G display. 16x4 backlit display. It has 15pins and a HD44780 chip.

I have wired it up like OcMods show here. With no resistor and the contrast is directly wired to ground.

My problem is that NOTHING showes up on the display. I got LCDisplayer to work, and LCDPRINT.EXE seems to work ok.

While checking the data lines, it seems like D7 (Paralell port pin9, LCD pin 14) never hits 5V like the other data lines that changes between 0V and 5V. D7 changes between 0 and 1,5V.

I thought my port was messed up and wired up a printer card. The card showed up win98 and both programs stated above seem to work. But nothing shows up on the display. All wires goes through my printer cable / DB25 connector. BTW: the backlight works!

Any ideas what could be wrong??

__________________
Car: 1995 Saab 900S 2.0 ,Sapphire GPS ,Mini-Mag WiFi antenna
HU: Pioneer DEH-P7100R AMP: XM-4060GTX Sub: XS-L121P5
Old car that got stolen: 1984 Nissan Cherry (Pulsar), PII-400,64MB Ram,35GB HD,Keypad,CF 634 Display

MP3Car.com

 

Rob

First don't worry about D7, the data sent to the LCD is all in ascii, and the highest value you'll use is, z which is 122 or 01111010

Also when it's powered up, and there's no control software running, do you get black boxes on the screen, if you don't then it's going to be a problem with the contrast.

I hope that helps, a bit.

Rob

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Tech^Cellfish

I get no black boxes. Is that standard on all HD44780 displays?

Maybe I'm able to dig up a potmeter to try and adjust the contrast. Thanks for the help.

__________________
Car: 1995 Saab 900S 2.0 ,Sapphire GPS ,Mini-Mag WiFi antenna
HU: Pioneer DEH-P7100R AMP: XM-4060GTX Sub: XS-L121P5
Old car that got stolen: 1984 Nissan Cherry (Pulsar), PII-400,64MB Ram,35GB HD,Keypad,CF 634 Display

Machs_FueL

I know this is completly off topic, but whats a Nissan Cherry?

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Tech^Cellfish

It's my car. a Nissan Cherry. (earlier models are made by Datsun, but thank god mine is a Nissan). My sig is wrong, because it is a 1984 model, not 1986 as I first thought.

__________________
Car: 1995 Saab 900S 2.0 ,Sapphire GPS ,Mini-Mag WiFi antenna
HU: Pioneer DEH-P7100R AMP: XM-4060GTX Sub: XS-L121P5
Old car that got stolen: 1984 Nissan Cherry (Pulsar), PII-400,64MB Ram,35GB HD,Keypad,CF 634 Display

Meatballman

In the United States it is known as the Nissan/Datsun Pulsar:

http://www.cherry.nsb.pl/?l=en
http://www.geocities.com/motorcity/1415/

[ 02-04-2002: Message edited by: Meatballman ]

Tech^Cellfish

I tried to solder on a potmeter. It didn't change how things worked. I did also try to feed the display with 5V/Ground through regular cables, instead of through the signal cable. But it didn't help..

Seems strange that nothing is visible on the display. I don't think it is broken, as I bought it new off eBay.

Anyone have any ideas?

__________________
Car: 1995 Saab 900S 2.0 ,Sapphire GPS ,Mini-Mag WiFi antenna
HU: Pioneer DEH-P7100R AMP: XM-4060GTX Sub: XS-L121P5
Old car that got stolen: 1984 Nissan Cherry (Pulsar), PII-400,64MB Ram,35GB HD,Keypad,CF 634 Display

MP3Car.com