MB-6582 LCD wiring question

[Labelwhore]

I'm putting together a MIDIBox SID using the MB-6582 baseboard, and have a question about wiring the LCD. Are the pins at J15, the same as described here? I assume they are, but just wanted to be sure.

[Wilba]

It's the same, that's why I linked to that PDF from here.

For extra clarity, J15 is identical in position and pinout to the standard Core, so you can refer to the Core module schematic diagram here.

[Labelwhore]

I figured that was the case. Thanks a lot for confirming my suspicion :) I searched ucapps, the wiki, and the forums for about an hour and a half last night and couldn't find anything that would confirm that for me.

...another stupid but related question ;) do I wire up my LCD like a 4 bit display in the same way I would with the standard core? or use all 8 data lines? again, sorry for the stupid question but I come from the school that believes the only truly stupid question is the one that goes unasked.

Edited June 10, 2010 by Labelwhore

[Wilba]

There are no stupid questions, only stupid people. :wink:

Quote from here:

*Note* Please see Wilbas post here, for advice on how to connect the LCD to the control surface.

It doesn't go into specifics of the 4-bit vs. 8-bit thing.

Since the two PIC18F4685 pins for the CAN bus are the same as have been used by MIDIbox Core modules for J15, then by default, MIOS on PIC18F4685 uses 4-bit. Conveniently, this means you only need to leave four pins of J15 open and then the same cable you would use for 8-bit will also work... i.e. if the unused 4 data lines are left open at Core:J15, then the LCD will work in 4-bit mode. This is what I've done on the MB-6582 PCB.

So you should just make the cable as if it's intended for 8-bit, according to the "older" wiring diagrams. Since you'll probably be using a 16-wire ribbon cable anyway, it doesn't make much difference, and it's easier to follow the wiring diagram if you forget about which four wires won't be used.

[Labelwhore]

Thank you sir! You're a gentleman and a scholar. :thumbsup:

[neilbaldwin]

I have a question regarding the pin numbering of J15 on Rev 2 boards (only saying that in case it's relevant - I don't have a Rev 1 to compare)

 

The information and Jim's PDF suggest that the numbering of the pins on J15 goes in a left-right sequence:

 

1 - 2

3 - 4

5 - 6

.......

15 - 16

 

whereas on the PCB the pins have numbers on them, #1 being the pin closest to the top-right of the core PIC then #8 being the corner below that, #9 being opposite and #16 in the opposite corner:

 

1    9

...  ...

8    16

 

which doesn't match up with the pins show in Jim's PDF.

 

Which is the right pin layout for J15 (Rev2)? Jim's PDF or the unusual numbering system suggested on the board printing?

 

Thanks,

 

Neil

 

(Oh, yeah, of course, I followed Jim's wiring and I'm just getting two rows of white squares on my LCD, hence the question. The contrast and brightness trimmers work so something is connected up right  :smile: )

[neilbaldwin]

Anyone?  :no:

[freddy]

Two rows of squares sound like a contrast issue to me. Try messing with the trimmer to see if it helps.

[neilbaldwin]

It turned out to be the fact that at that point I'd still not managed to upload MIOS properly. I have now and the LCD is working fine  :smile: