Hi, I’m building my own board on Atmega328pb-u on 3.3V.
I tried to upload bootloader via Arduino UNO to Atmega328pb with no success.
Selected board: Arduino Pro or Pro Mini - Atmeha328p (3.3V 8Mhz)
Programmer: Arduino as ISP
Target board is connected to Arduino via ICSP connection and RESET pin is connected to 4.
Status LEDs connected to programmer show error (red LED) and IDE prints error like this:
avrdude: Device signature = 0x000000 avrdude: Yikes! Invalid device signature. Double check connections and try again, or use -F to override this check.
I have seen other topics explaining that this might be the cause missing of on-board oscillator but mine has one at 8MHz (schematics in the attachemts).
I also tried to upload Optiboot bootloader but avrdude shows the same error.
Switching Atmega328p signatures to Atmega328pb in avrdude config didn’t worked too.
I think it might be fault of oscillator, here is link to it:
I haven’t used external capacitors because schematic symbol showed them as part of the object. Probably that’s the cause of problem so I tried to upload bootloader with fuses set to internal oscillator (it does not matter for me) but I couldn’t find any information about it.
If somebody knows how to do it or have other clues please comment.
Note! RESET pin on schematic is connected to GND with 0R resistor - in reality this resistor is missing and I use it’s pads to make connection with jumper wire when I want to reset the board.