(Topic changed to better described the problem and let others know it got fixed.)
Hi all! I just ebayed what was called "NEW ATmega2560-16AU CH340G MEGA 2560 R3 Board" and am having some troubles with it. (I suspect it being a clone since it doesn't have the six-pin header near the USB port, only a six-pin ICSP header next to the main Atmel chip.)
When I first got it, I uploaded the 'Blink' sketch just to test it. That worked well. After that, I can't upload sketches anymore!
However, if I connect an USBasp to the ICSP header and choose 'Burn Bootloader' from the Arduino IDE, then that seems to always succeed, and the next time I plug in the Arduino via the USB port, again I can program and upload ONE sketch - it refuses to accept new sketches after that.
I can seemingly repeat this over and over.. re-burning the bootloader and then being able to upload a single sketch through the CH340G chip/USB port. (It doesn't matter if it's the same sketch that just worked, that I try to upload again - it's only the first time I upload that will work, all subsequent tries gives 'timeout' from avrdude.)
Any help on this, please? Is there a particular bootloader binary I should put on this board that will work better than what's in my Arduino IDE? (Arduino 1.6.6/Linux 32-bit, if that helps.)
The baffling part is, how come the first upload works without problems but after that I'm "locked out" even though I'm using all the same settings? :/
Board Arduino Mega, Processor Mega 2560, Programmer AVRISP mkII, avrdude says this while programming the first sketch: Using Port : /dev/ttyUSB0 Using Programmer : wiring Overriding Baud Rate : 115200 AVR Part : ATmega2560 Chip Erase delay : 9000 us PAGEL : PD7 BS2 : PA0 RESET disposition : dedicated RETRY pulse : SCK serial program mode : yes parallel program mode : yes Timeout : 200 StabDelay : 100 CmdexeDelay : 25 SyncLoops : 32 ByteDelay : 0 PollIndex : 3 PollValue : 0x53 Memory Detail :
Something just hit me - can it be so evil that the Mega2560 chip also has the bootloader on it, and when I upload my first sketch, I also overwrite the bootloader?? That would certainly explain why it won't respond to further upload attempts, since the Blink example code doesn't include a fresh bootloader.. :P But if that's the case, how do I keep from erasing the bootloader when uploading new sketches? Or should I resign to just upload via the ICSP port and skip "the easy way" of upload-and-testing through the USB port?