Flashing firmware problems


I had problems with my 4PM Shruthi. It kept restarting itself on various events, for example pressing the encoder button, or sending midi events, but it was kind of random and not reproducible. I checked everything on the hardware side and all seems good, so I thought maybe theres something wrong with the firmware and tried reflashing it.

When I run “make bake_all” I always get:

avrdude: Device signature = 0x000000
avrdude: Yikes! Invalid device signature.
Double check connections and try again, or use -F to override
this check.

I can flash other Shruthis just fine with the same procedure, I’m using an Atmel AVR ISP MKII programmer.

Could there be something wrong with the Atmega644P?


I don’t think you’d be getting a message like that with a chip that can boot and display the splash screen. Are you sure it’s not a problem with the ISP connector instead?

Hmm I don’t think so. I tried swapping in another Atmega644P, and now I get a different wrong ID:

avrdude: Device signature = 0x0f0102
avrdude: Expected signature for ATMEGA644P is 1E 96 0A
Double check chip, or use -F to override this check.

After the unsuccessful flashing, there is no bootscreen anymore, just one row of blocks, like on an empty Atmega.

Have you tried using another working board as your flashing rig?

Yes, on another working Shruthi, the same procedure works fine.

I now tried flashing the chip that gives Device signature = 0x000000 with another digital board and it also works fine.

You definitively have some bad power, sockets/connections or cold solder joints issues.
Did you try the working control board with the 4PM filter board?

Yes, works fine.

I checked all the solder joints and everything seems good. Only the ones beneath the LCD are hard to check, and I would rather not desolder the LCD :confused:

Checked, or re-heated ?
While I so far haven’t managed to ever get the cold solder joint experience, I know from the forums that they are apparently very difficult to detect -So, if you haven’t re-heated all the relevant connections, please do so :slight_smile:

I think the relevant connections are mostly the Atmega socket, and thats completely under the LCD :confused: I think I may have to desolder it after all. Are there some points not under the LCD worth checking?

Why don’t you just grab another Digital Board. No need to pretend you only have one…

Hm I could build another one… But this is the nice white special edition :confused:

Cut the pin header for the lcd, desolder, reheat pins on socket, put in lcd again :slight_smile:

Or remove the Plastic from the ISP Header, reheat, pray.

I don’t think its just the ISP header. All the random crashes must be linked to this too…

Alright, I managed to remove the LCD without totally destroying everything somehow (man, I HATE desoldering…). The solder joints all looked OK, but I reheated all of them and its now working fine. Thanks everyone!