Hi,
I connected 2x16 LCD today to my working CORE module, however the LCD showed no signs of working, no black lines, nothing. When the underside began to overheat. So I de-soldered it and now the core module isn’t sending or recieving midi signals.
Any help would be greatly appreciated!
doh!
Grab the schematics and your LCD’s datasheet and make sure you wired it right. When you find the mistake (sorry but I think you will find a mistake, given what you said) then post it here and maybe we can figure out what got fried :-\
Good luck mate!
How i love that even binary designs have a mind of their own.
sorry about the previous post, i was on my way out and i really needed to know what was wrong with thec core. Mainly for my sanity.
I came home tonight and suddenly when i tried the core, everything worked perfectly. so i will try the LCD again, following all instructions of course.
thanks stryd.
I’m still not having any luck with the LCD. I can’t find the datasheet anywhere, though I have a small reference sheet that came with it. I connected just VSS, VDD and V0 as Thorsten mentioned in another thread to see if i saw anything, but still nothing, even when i changed the contrast trimpot. The LCD just gets hotter and hotter on the two black circles on the underside.
Any ideas? ???
Those black dots have the driver IC’s under them so that’s bad 
Hard to say what’s wrong, if you know you’ve connected power to it correctly, then perhaps it was DOA?
In my last efforts, i switched around VSS and VDD and for some reason, the LCD works but is just displaying black blocks.
It was just strange. It says 1 and 2 are VSS and VDD respectivley, but for some reason 2 is VSS and is VDD. Just plain strange. It’s probably something wrong with how i did it.
Any ideas on the black blocks? should i reverse all wires like with 1 and 2? I’ve tried changing the trimpots but that just fades them out.
black blocks are correct until you load up mios, when it should say ‘Ready.’.
I had an issue with 4x20 LCD. I swapped data lines with power/enable/… lines.
The one “black dot” got heated up…and I have never ever got any good response from that LCD afterwards. Hey, at least now I know where the Paralel interface logic is without tracing.
You are lucky that your LCD is probably ok. To be sure, you’ll have to connect all comm lines and upload MIOS. Only when you “READY.” onscreen, you can be sure that all is well.
Sorry i should’ve already stated that i have loaded the MIOS and a program. The core sends a bunch of random midi messages as per usual if there are no pots/buttons present
I’ve quadruple checked all solder junctions, unsoldered them and resoldered them a few times and i am positive that everything is as it should be. MIOS is installed and the MB64 program loaded in. But still i get the top bar of black blocks and half the lower blocks black. They disappear when i move the contrast pot a bit. I checked between VDD and the other points on the core with a multimeter, all except pin5 (r/w) and B+ read as 5.14V
I found out that the company i bought it from sent me the wrong pin sheet, so i was right with the gnd and vdd switched around.
Any help would be greatly appreciated! ???
There is a lcd_interconnection test available at the MIOS download page which helps you to find out, if the cables between core and LCD are wired correctly. It doesn’t ensure if the pinning is correct (thats not possible), but it might give you a hint
Best Regards, Thorsten.
Thanks Thorsten I will give that a try. 
Just to make sure that the MIOS was infact installed correctly, i reuploaded the mios_v1_9c_pic18f452.hex file. Firstly it would say "Starting upload of mios_v1_9c_pic18f452.hex
Hex file contains code in MIOS range, forcing reboot!" But then it would not progress from there. So i put it on manual mode, which then said:
Sending block 00000400-000004FF
Sending block 00000500-000005FF
Sending block 00000600-000006FF
Sending block 00000700-000007FF
Sending block 00000800-000008FF
Sending block 00000900-000009FF
Sending block 00000A00-00000AFF
Sending block 00000B00-00000BFF
Sending block 00000C00-00000CFF
Sending block 00000D00-00000DFF
Sending block 00000E00-00000EFF
Sending block 00000F00-00000FFF
Sending block 00001000-000010FF
Sending block 00001100-000011FF
Sending block 00001200-000012FF
Sending block 00001300-000013FF
Sending block 00001400-000014FF
Sending block 00001500-000015FF
Sending block 00001600-000016FF
Sending block 00001700-000017FF
Sending block 00001800-000018FF
Sending block 00001900-000019FF
Sending block 00001A00-00001AFF
Sending block 00001B00-00001BFF
Sending block 00001C00-00001CFF
Sending block 00001D00-00001DFF
Sending block 00001E00-00001EFF
Sending block 00001F00-00001FFF
Sending block 00002000-000020FF
Sending block 00002100-000021FF
Sending block 00002200-000022FF
Sending block 00002300-000023FF
Sending block 00002400-000024FF
Sending block 00002500-000025FF
Sending block 00002600-000026FF
Sending block 00002700-000027FF
Sending block 00002800-000028FF
Sending block 00002900-000029FF
Sending block 00002A00-00002AFF
Sending block 00002B00-00002BFF
Sending block 00002C00-00002CFF
Sending block 00002D00-00002DFF
Sending block 00002E00-00002EFF
Sending block 00002F00-00002FFF
Sending block 00003000-000030FF
Sending block 00003100-000031FF
Sending block 00003200-000032FF
Sending block 00003300-000033FF
Sending block 00007C00-00007CFF
Sending block 00007D00-00007DFF
Sending block 00007E00-00007EFF
Sending block 00007F00-00007FFF
Upload process complete
So i thought all was good. However when i reboot the core, it sends alot of sysex messages followed soon after by the random midi messages (as the unused pins are not clamped to ground)
This is what the midi in box says:
Sysex message: F0 00 00 7E 40 00 0E 0B 01 F7
00000000018160 ms | Sysex message: F0 00 00 7E 40 00 0E 0B 01 F7
00000000018164 ms | Sysex message: F0 00 00 7E 40 00 01 F7
00000000018166 ms | Sysex message: F0 00 00 7E 40 00 0E 0B 01 F7
00000000018170 ms | Sysex message: F0 00 00 7E 40 00 01 F7
00000000018175 ms | Sysex message: F0 00 00 7E 40 00 01 F7
00000000018187 ms | Sysex message: F0 00 00 7E 40 00 01 F7
00000000018190 ms | Sysex message: F0 00 00 7E 40 00 0E 0B 01 F7
00000000018193 ms | Sysex message: F0 00 00 7E 40 00 01 F7
00000000018195 ms | Sysex message: F0 00 00 7E 40 00 0E 0B 01 F7
00000000018199 ms | Sysex message: F0 00 00 7E 40 00 01 F7
00000000018201 ms | Sysex message: F0 00 00 7E 40 00 0E 0B 01 F7
00000000018205 ms | Sysex message: F0 00 00 7E 40 00 01 F7
00000000018207 ms | Sysex message: F0 00 00 7E 40 00 0E 0B 01 F7
00000000018210 ms | Sysex message: F0 00 00 7E 40 00 01 F7
00000000018213 ms | Sysex message: F0 00 00 7E 40 00 0E 0B 01 F7
repeat for a while then:
00000000026219 ms | [D0 00 00] Channel 1: Channel Pressure value: 0
00000000026220 ms | [D0 00 00] Channel 1: Channel Pressure value: 0
00000000026220 ms | [D0 7E 00] Channel 1: Channel Pressure value: 126
00000000026220 ms | [D0 40 00] Channel 1: Channel Pressure value: 64
00000000026221 ms | [D0 00 00] Channel 1: Channel Pressure value: 0
00000000026221 ms | [D0 01 00] Channel 1: Channel Pressure value: 1
00000000027470 ms | [82 00 00] Channel 3: Note Off C-1 velocity: 0
00000000027471 ms | [82 7E 40] Channel 3: Note Off F#9 velocity: 64
00000000027471 ms | [82 00 01] Channel 3: Note Off C-1 velocity: 1
00000000028719 ms | [F6] Tune Request
00000000030470 ms | [C0 00 00] Channel 1: Program Change no: 0
00000000030470 ms | [C0 00 00] Channel 1: Program Change no: 0
00000000030470 ms | [C0 7E 00] Channel 1: Program Change no: 126
00000000030470 ms | [C0 40 00] Channel 1: Program Change no: 64
00000000030471 ms | [C0 00 00] Channel 1: Program Change no: 0
00000000030471 ms | [C0 0E 00] Channel 1: Program Change no: 14
00000000030471 ms | [C0 0B 00] Channel 1: Program Change no: 11
00000000030472 ms | [C0 01 00] Channel 1: Program Change no: 1
00000000035219 ms | [90 00 00] Channel 1: Note On C-1 velocity: 0
00000000035219 ms | [90 7E 40] Channel 1: Note On F#9 velocity: 64
00000000035220 ms | [90 00 0E] Channel 1: Note On C-1 velocity: 14
00000000035221 ms | [90 0B 01] Channel 1: Note On B-1 velocity: 1
I hope i haven’t blown the pic up
If I move sliders or pots on my midi keyboard (through which the core is routed) it comes up correctly in the midi in section.
Does this all look ok?
Thanks again.
Under such unstable conditions, always upload code with the “feedback from core” option. Where the bootloader doesn’t continue until a successfull response has been received. Without this mechanism, it can happen that invalid code will be executed, which can do a lot of random, but also dangerous stuff (e.g. erasing the flash)
Best Regards, Thorsten.
Turns out i had a bit of a midi loop going on, so that was fixed and MIOS uploaded successfully as well as the MB64 program. I unplugged the LTC module as i found out it was causing the random sysex messages, so i’ll have to work that one out. Still no LCD though.