www.megadrum.info

Hi!

I've built the 56i one board and I can not make it to being recognized by windows. The Atmega is a protected one I ordered from dmitri long time ago (bulk order #2). More data to complete the case:

- Atmega644 with protected bootloader.
- 20 and 12 mhz crystals both in right place.
- So far, everything but the USB seems to work OK: LCD screen show the activity bars and they move if a connect and hit a piezo.
- Cheked USB wire (Ok).

I'm able to program the PIC18F2550 with WinPic without problems/errors and I tried changing the 15k (R28) for a 47k in order to try the alternative USB MIDI Firmware, but got the same result: USB device not recognized in windows.

Some pics (last two shots were taken without all components soldered):




Besides shorts and breaks in traces, what else can I check ?

Thanks in advance!

Possible causes:
1. Wrong firmware programmed into PIC.
2. Wrong PIC crystal frequency.
3. Wrong USB wiring.
4. Bad USB cable.
5. Bad USB socket.
6. Bad soldering, shorts/breaks on the board.
7. Wrong components around PIC.

i've just noticed that USB device is perfectly recognized when I remove the Atmega, does it mean something?

It does. Soldering problems on the board, most probable shorts somewhere.

there was a short!! thanks dmitri.