LCD issues

[dmitri]

Might this be why my LCD doesn't work?

It might. Also read "7. Having LCD problems?" in MegaDrum FAQ. Read it before posting in this forum!

[operators123]

Yeah I've read that and tried everything, I've narrowed it down the the atmega having a problem since the wiring, voltages and LCD are working correctly.
The problem is I can't reprogram the fuses, as the chip isn't being read properly by my computer, although it worked before.

[dmitri]

If you programmed incorrect fuses then you either
1. have to use recovery. viewtopic.php?f=3&t=42&p=278
or
2. use proper Atmega programmer
or
3. get a new blank Atmega.

[operators123]

Ok, if I get a proper programmer, can I use the ISCP header on the board? (the 5 pin one for atmega)

[dmitri]

You can, but the ISP header on the MegaDrum board has non-standard pinout so you will have to use a non-standard cable between the MegaDrum board and the programmer.

[operators123]

I think I might have spotted a potential error, I bought this 16mhz crystal from maplin http://www.maplin.co.uk/general-purpose ... case-31822 since I accidentally ordered the wrong one from farnell.
The description says it needs 32pf load capacitors. Where as usually you'd use 22pf as I have.
Might this be a problem?

[dmitri]

I doubt very much.

[operators123]

Sorry to bump, but I can't get my LCD to work for some reason. Here's what information I can give,
connections between atmega and LCD are functioning, atmega is programmed with last unencrypted firmware with correct .hex file, crystal and capacitors are correct, values of resistors and capactior around pin 3 of LCD correct, download/file.php?id=1491 fuse bits set with ponyprog (managed to get an atmega644), backlight is working, +5V between pins 1-2 of LCD, pin 3-GND is 4.7V (too high), tried using buttons to adjust - no luck, and shorting pin 3 to ground - I see black boxes.
And I've checked for shorts/breaks.

Any ideas

EDIT: strangly when I power up MD, the led stays light for about a minute then turns off.

[dmitri]

Seems like you expect some magic tip. I'm afraid I cannot give you one. I gave you the link where I described troubleshooting LCD and you should follow it thoroughly.

[operators123]

Alright, I've reprogrammed atmega and fixed up a tiny soldering joint, and well the problem's solved. I thank you for your patience

Anyway, the display is fine, but all the VU meters are on full, also on some of the settings, (for example 'all channels') I change, it says done, but then I go back to that setting, and it's on 'NO'.
Is this likely to be a hardware or atmega issue? Because as far as I know the digital board should be fine. I've also connected the analogue board, but the results are the same.
Thanks in advance