I made a PCB with an Atmega32U4 that I'd like to program using Arduino to do some serial communication. I've read the first step is to burn it with the Arduino bootloader, there seem to be a few versions online that are board-specific, like caterina, optiboot, sparkfun's Pro Micro, this one by Adafruit, etc.
None of the ones I've tried installing work, and I get errors like this:
avrdude: verification error, first mismatch at byte 0x7000
0x00 != 0x55
I'm using the Atmel AVR mkII ICSP that I've connected properly, and I power the MCU with USB while trying to burn the bootloader. I've been using the Arduino mac application for the process.
I haven't been able to find good sources by googling, does anyone know how to solve this issue? thanks!
The Arduino Micro bootloader is probably the only one which will work on that particular chip. I imagine it's identical to the Pro Micro.
That error says that the programmer couldn't program the chip. It is trying to verify that the program was written correctly and it is finding that it was not written. It doesn't matter which bootloader you choose - this error is a fundamental problem with the ISP, not the bootloader itself.
Do you have anything else connected to the ISP lines during programming? Can you power the board through the ISP header and not USB?
MorganS:
The Arduino Micro bootloader is probably the only one which will work on that particular chip. I imagine it's identical to the Pro Micro.
That error says that the programmer couldn't program the chip. It is trying to verify that the program was written correctly and it is finding that it was not written. It doesn't matter which bootloader you choose - this error is a fundamental problem with the ISP, not the bootloader itself.
Do you have anything else connected to the ISP lines during programming? Can you power the board through the ISP header and not USB?
You are right, powering the circuit off a battery instead of USB allowed the bootloader to burn.
Slightly different newbie issue now: after the bootloader has been burnt, and the circuit plugged through USB, it doesn't appear in the Arduino app under the list of serial ports in "port" (as normally would when an arduino board is connected via USB). I'd like to be able to communicate with the Atmega32U4 and see output in the serial monitor etc, do you know how to do this?