Firmware keeps disapearing

[CyberFly]

I have a 2.8 Synthex kit with a firmware problem. When I turn the MD off the firmware disappears. I have to upload the firmware via midi ox every time I use the MD.

I power the MD via usb only, there are no parts on it for external power supply.
Should I build in a battery like on a pc's mainboard?

Please help.

[Firelord]

When I turn the MD off the firmware disappears.

Please provide more details on this. What do you mean by 'Firmware disappears'? MegaDrum doesn't boot anymore after powering it down? Blank LCD? Persistent bootloader mode?

[jman 31]

Should I build in a battery like on a pc's mainboard?

Please help.

No. The atmega does not lose it's info when their is no power present. Like Firelord said we need more info.

[CyberFly]

I did a few more tests, here are the results.
Every second time I start my MD the firmware is gone. It asks for updating firmware without pressing the left button during start up.

Here is how its goes:
I upload the firmware to the MD.
The MD works as it should.
I turn off the MD.
I turn the MD on, it works as it should.
Second time I turn on the MD the firmware is gone and it wants to update.

[Firelord]

Second time I turn on the MD the firmware is gone and it wants to update.

I assume MD goes into firmware update mode. Are all of MegaDrum's controls functioning properly? I would recommend checking the connection between your controls and the PCB. There might be a short or wiring problem or something similar.

And I specifically stress the following: the firmware does not go away. It is still there, it's just that the bootloader is activated during MD boot for some reason.

[dmitri]

A few notes:
1. MegaDrum enters a bootloader mode only if button LEFT is pressed during powering up or if there is no MegaDrum firmware programmed (or it has been erased) and LEFT button is pressed after powering up.
2. Two last versions of the bootloader have protection from accidentally erasing MegaDrum firmware. In the old versions of the bootloader it was possible to accidentally erase MegaDrum firmware by just pressing buttons in a bootloader mode.

[CyberFly]

I did a few more test without the buttons connected. Also, there is no short circuit on the pcb. If there was the MD should constantly respond to button input, shouldn't it?

After ''losing'' the firmware I restart the MD. Now it shows a row of black blocks on the top line of the LCD. I turn the MD off and on again. It asks me to upload firmware. (Please note that I don't press any button, they are not connected.)

Can the boat loader become broken?

[dmitri]

I cannot think of anything. Even with if it enters the bootloader, because it thinks the LEFT key is pressed (short circuit, excessive flux) with the latest firmware it won't erase MegaDrum firmware just because it entered the bootloader, you should be able to restart and get into MegaDrum firmware at least from time to time.

[Firelord]

Can the boat loader become broken?

Yes, it can. Although unlikely, this has happened to some of MD users without an apparent reason. The only solution in this case is to reprogram ATMega via ISP. That's what I would try in your case.

Did MegaDrum work for you properly at all? Had this problem with F/W been effective right from the start (~ after you finished the assembly)?

Also, if you provide pictures of your PCBs, maybe we can rule H/W problems out.

[CyberFly]

While checking the solder joints on the pcb I didn't find any short circuits or broken joints. Then my friend noticed that the atmega wasn't placed in the socket correctly. After pressing it firmly in the socket the problem was solved.
I must have been too careful while placing the atmega in the socket.

Thanks for the advice and help.