Simple LCD code not working..

[sayzer]

As an apprentice, I , respect masters always.



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[davewanna]

Thanks all for the replies.. I originally had the TRISB = 0, but removed it to simplify, added it back in, no difference. Added the cammandus & dataus lines, still no difference.

I'm using the 16F84a for now, so no A/D, no LVP, I've made sure it has XT OSC.

And have fiddled the contrast pot, I know it's right now tho, as the blocks come up on the first line, and then when I LCDOUT $fe,1.... The screen clears.

I even measured continuity between the data pins on my pic, and the pins on the LCD incase I had a problem on my breadboard.

I think I'm going to have to get another LCD panel to rule that out as being the problem...

Any more suggestions I'd be happy to hear, but I now presume it's a hardware fault, seeings how it doesn't seem I stuffed up any of the code.

Thanks again,

Dave

edit - R/W is also tied low... I know this as when I first connected it, I tied it high, and nothing happened, when I tied it low, it now clears...

[davewanna]

Just a follow up...

I got another LCD the same, connected it, it came up with crazy characters on the screen... In desperation I swapped the cable I was using (IDE HDD cable) and low and behold it works.

On closer inspection, the cable I was using originally, has more conductors in it than pins on the plug. I pulled the plug apart, and there is a big copper bus-bar that connects certain pins to each other, and also I assume to ground. Must give some kind of shielding effect.

Anyway all sorted.

Thanks to everyone that helped...

Cheers
Dave

[skimask]

On closer inspection, the cable I was using originally, has more conductors in it than pins on the plug. I pulled the plug apart, and there is a big copper bus-bar that connects certain pins to each other, and also I assume to ground. Must give some kind of shielding effect.

Info you: Older IDE cables had 40 pins, newer ones have 80 pins, 40 normal + 40 grounds/shields, for use with the higher DMA speeds and transfer rates in the newer ATA spec's.