Megadrum 56i single board setup issues

[Chunky Kev]

If i run it without pic can I just ignore it or does it need to be removed?

Just ignore it.

Any other ideas why it doesn't seem to be getting anything from my Midi USB cable, or don't I need this either, should it run with just the USB cable connected to the board

You need the Midi usb cable to send and receive midi data. The usb cable is providing power, so you'll need that plugged in too.

My PC does not seem to be recognising it though?

Recognising what? The midi-usb cable or the MD->PC usb cable? As stated, unless the pic has the firmware the PC will not recognise it. If your PC does not detect the midi-usb cable then that is probably the cause of your problems and is likely an issue with the cable itself or with drivers on your PC. Does the midi-usb cable have a LED that lights up when midi notes are sent? Most do, so if it blinks when you hit pads, the problem is probably in the PC, and if not, you'll need to check for faults on the board because your MD might not be sending any midi notes.

Hi ignotus,

thanks for getting an answer to me. I get nothing on LEDs on my Midi cable, so that makes it sound like an issue with my board. Back to checking everything through and seeing if there are any faults I guess. Any suggestions where there might be something, or is it a case of could be anywhere?

[ignotus]

Check the traces and components that are related to midi in and out; from pins 14 & 15 of the atmega out to the midi ports.

[dmitri]

Also, if Atmega's fuses are not programmed correctly or there is a mismatch between the firmware and Atmega's crystal then MegaDrum won't produce MIDI signal with exact speed of 31250 Bit/s.

[Chunky Kev]

Also, if Atmega's fuses are not programmed correctly or there is a mismatch between the firmware and Atmega's crystal then MegaDrum won't produce MIDI signal with exact speed of 31250 Bit/s.

Hi Dmitri, the Atmega came from you a couple of weeks ago, preinstalled with firmware 20130612 20MHz. I have done nothing but plug it into board since it arrived. Which crystal do you refer to, is it one on the board?
How do I know if fuses are programmed correctly?

[dmitri]

If the chip came from me than it has all the fuses programmed correctly. You should use a 20MHz crystal with it.

[Chunky Kev]

There are 2 crystals on the board, the one next to Atmega is a 20Mhz and the other is a 12Mhz. That is correct isnt it.

[dmitri]

Yes, that' correct.

[Chunky Kev]

Good, that's narrowing things down at least. I am away for a while and will then start trying to check on these pin outs 14 and 15 to see if there are any issues along their way. I did have a couple of capacitors in the wrong polarity, could they have done any more damage than just to themselves?

[Chunky Kev]

Right, spent quite a bit of time going through soldering joints, and traces and tidied up a few bits, still nothing happening on USB connectivity to PC. I did notice the LCD display backlight stayed on after switching Megadrum off, when I wiggled board it went off, so I have re-soldered USB and tidied a few other bits. Now it fades and goes off when I turn Megadrum off, but after about 10 seconds fades back up to a dim glow. Any ideas if this might signify something that could be the cause of both issues?

[Chunky Kev]

Anyone got any thoughts or ideas on previous post and what might be wrong, need help please.