www.megadrum.info

Hey everyone,

I've hit (yet another) weird problem. When I power the MegaDrum up, it goes straight to the editing menu for CH07 (RideE), and flickers between that one and CH03 (Hi-HatE). I think those are the channels anyway, it flicks between them incredibly fast.

I can use the keypad to switch which options I am editing (Curve, Gain etc) but it constantly flicks between those two channels. Its as if I have an incredibly fast drummer hitting the two pads at the same time! The MegaDrum also does this when not connected to a pad :S

At the same time, it developed the fault that my laptop would not recognise it (USB Device Not Recognised) unless the Atmega was not connected (USB Running off Synthex's All in one V2.3). Same problem with multiplexers removed, and MIDI LED is on constantly! I do not have the MIDI ports connected so I cannot test the output, as the USB will not work either with the Atmega in place!

Using a simple voltmeter ( ) I can't see any data going into the Atmega from the Multiplexers, am I right in thinking that my Atmega has just lost it? I cant seem to find anything wrong with the rest, I mean this was my first project, and although I have learnt masses along the way, the first bits I soldered are... a real botch job really but it seems to be in working order... apart from it doesn't work!

Is it worth buying a new Atmega? Probably the 644 from Synthex laptops need that bootloader!

Great thanks to everyone thats helped me so far by the way

Cheers, ohawker

ohawker wrote:I've hit (yet another) weird problem. When I power the MegaDrum up, it goes straight to the editing menu for CH07 (RideE), and flickers between that one and CH03 (Hi-HatE). I think those are the channels anyway, it flicks between them incredibly fast.

I can use the keypad to switch which options I am editing (Curve, Gain etc) but it constantly flicks between those two channels. Its as if I have an incredibly fast drummer hitting the two pads at the same time! The MegaDrum also does this when not connected to a pad :S

1. Is the HiHat pedal connected?
2. Power up MegaDrum while holding key RIGHT pressed (loads defaults). Is flickering still there?

1. I have no hi-hat pedal haven't built the actual kit yet just loose piezos to test!

2. Doesn't seem to make a difference, I don't even see the splash screen. Just jumps between the two channels

I can't see any issue :S it randomly started! Any other suggestions?

Thanks

Have you checked your welds ?
No short-circuit ?

Do you make pullup resistor modification for keyboard ?

ohawker wrote:1. I have no hi-hat pedal haven't built the actual kit yet just loose piezos to test!

When pedal is not present MegaDrum thinks the pedal is pressed. When in the menu and the pedal is pressed MegaDrum uses quick menu jumps, i.e. it jumps to a channels corresponding to a pad last hit. If, for any reason - e.g. parasite signals, bad soldering, too low threshold - several channels constantly register hits MegaDrum starts to jump around those channels. As a temporary workaround while you don't have a pedal, connect the HiHat pedal input over a 1k-10k resistor to +5.

I remember having had some flickering when I upgraded firmware. The old configuration settings could not be interpreted correctly and I had some really strange behaviour. Setting 'autoload config' to 'no' solved it.

With USB: Did you try using another usb port? This sometimes helps for me when I encounter USB related problems.

Synthex wrote:Do you make pullup resistor modification for keyboard ?

Happens with or without keyboard attached. Can't find any short circuits, like I said, the fault just randomly developed:(

UPDATE: The issue seems to have totally resolved itself. Well, the flashing anyway. Removing the Atmega and replacing it seemed to do the trick I have tried that but it never worked before! I get the feeling something else is wrong though, as my laptop does not seem to recognise it still. I am now afraid to remove the Atmega in case that has something to do with it!

Why would USB work without Atmega but not with? I thought that the power supply may not be powerful enough, but it seems ok! And these IC's hardly leech much power

Thanks for your help so far

ohawker

Beamtreetaker wrote:With USB: Did you try using another usb port? This sometimes helps for me when I encounter USB related problems.

Yep, with no joy

What is the voltage of USB with and without the atmega?

Open USB: 5.04V
Atmega: 4.985V
Atmega + USB PIC: 4.97V
USB PIC: 5.00V

Not much variation there! £3.50 multimeter probably