USB

[dmitri]

In the bootloader did you choose 16MHz?

[efbe]

In the bootloader did you choose 16MHz?

I received the Atmega from sysex, so I presume with bootloader.

But which ??

EFBE

[dmitri]

Does the bootloader in your Atmega have an option to choose crystal frequency?
If it doesn't, then your bootloader is fixed at 20MHz and you either have to
a) (recommended) program it with a new bootloader which support crystal frequency selection using ISP cable and an LPT port on a PC
or
b) (not recommended) try to program it with a 16MHz firmware while using a 20MHz crystal and after successful programming change back to the 16MHz crystal

[efbe]

Does the bootloader in your Atmega have an option to choose crystal frequency?
If it doesn't, then your bootloader is fixed at 20MHz and you either have to
a) (recommended) program it with a new bootloader which support crystal frequency selection using ISP cable and an LPT port on a PC
or
b) (not recommended) try to program it with a 16MHz firmware while using a 20MHz crystal and after successful programming change back to the 16MHz crystal

I did something else, I replaced the cristal again with the 20 MHz and could now up-date the Firmware.
The USB issue still remains. At least I can use the MIDI in / out again, untill I find out the other things.

Thanks,
EFBE

[dmitri]

Does the bootloader in your Atmega have an option to choose crystal frequency?
If it doesn't, then your bootloader is fixed at 20MHz and you either have to
a) (recommended) program it with a new bootloader which support crystal frequency selection using ISP cable and an LPT port on a PC
or
b) (not recommended) try to program it with a 16MHz firmware while using a 20MHz crystal and after successful programming change back to the 16MHz crystal

I did something else, I replaced the cristal again with the 20 MHz and could now up-date the Firmware.
The USB issue still remains. At least I can use the MIDI in / out again, untill I find out the other things.

Your Atmega is overclocked. Until it is overclocked you will not "find out the other things" which will
fix any other issues. Your Atmega can even overheat, explode and start a chain reaction.

[Synthex]

Your Atmega can even overheat, explode and start a chain reaction.

... Overclocked Atmega works well.

[dmitri]

It may, it may not work well. See my comments on the bootloader thread. I myself sometime experience issues with 'overclocked Atmega32/USB' combination, e.g. USB not being detected or MegaDrum restarts unexpectedly when doing two way sysex communication.
When I downclock to 16MHz I don't experience any such issues at all.

[efbe]

It may, it may not work well. See my comments on the bootloader thread. I myself sometime experience issues with 'overclocked Atmega32/USB' combination, e.g. USB not being detected or MegaDrum restarts unexpectedly when doing two way sysex communication.
When I downclock to 16MHz I don't experience any such issues at all.

\\

O.K.

Despite of all, at the moment everything works again, even USB.

I will keep You informed if the thing explodes and or create maybe a black hole.

Thanks anyway.

EFBE

[CairnsFella]

Just want to say.. very very nice looking megadrum.

I was reluctant to post any pics of my build as I knew mine looks quite poor.. but yours makes me feel like throwing mine in the bin

... well.. not quite, as it does work at least... but very well done anyway.

[gyro]

It might be that your USB ports on the pc don't have enough power to feed your Megadrum. As you probably know, one USB port can deliver 500mA max. You can try with a powered hub to see if it works or you can change your megadrum to be powered from an external power supply and cut the power lines to your usb cable. Be warned : if you don't know how to do it that way, ask ! Otherwise you can ruin some of the more expensive parts. I received my pcb today, but as I'm a busy bee, it might take a while to assemble and test things (have to make my pads and cymbals also ...)

My 2 cents,
Gyro.