I’ve been strugling with this issue for quite some time now, so lets see if someone from the forum can help. I used to download the boatloader in an ATMEGA 328P-AU (tqfp 48 package) and then upload sketches.
I tried 3 different resellers and all send the same different chip:
Farnell answers in a reply: right now this chip seems to be replaced by a chip with another inscription with U-TH on the end. (see photo).
I’ve contacted manufacturer but they didn’t respond.
Problem: with this chip the bootloader optiboot_atmega328.hex still goes in, but the uploads from sketches won’t work anymore.
Verbose messages are:
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x15
Maybe someone knows if and which other bootloader is necessary?
Reportedly, package code is no longer marked on the chip.
U-TH means device information, country of origin.
Anyway, you could try to read out the flash to see if the optiboot is there. Optiboot is a part of Arduino SW as HEX for 16MHz. It is standard bootloader for UNO.
There is no problem with uploading the default optiboot_atmega328.hex bootloader. But in contrary to the -AU suffix, these chips stop during the start of the uploading proces...
Also I noticed the chips are replaced on the mini-nano so there should be a way.
Hope someone can help with the next step.
Problem: with this chip the bootloader optiboot_atmega328.hex still goes in,
There is no problem with uploading the default optiboot_atmega328.hex bootloader.
How have you verified that the bootloader has correctly uploaded?
Are you able to upload a test sketch (ie blink) using the external programmer and verified that it is running (ie is the LED blinking?)?
I gather you are using the ATMega on a custom PCB? Please post a schematic and a photo of your populated PCB.
You can also readout the flash and check it if the bootloader is correctly uploaded.
In the end it turned out to be an oscillator problem. Don't know what caused it, but the oscilloscope helped a lot. Thanks for the help guys!
Glad it worked but what was the problem with oscillator? Did you replace crystal or what?
Other people read this forum and maybe it can help so please, be so kind and describe it little more specific.
This would indeed be helpful, as you are not the only one who has reported strange issues that seem to be correlated with the new part number markings.