ast-can485 avrdude: verification error: content mismatch

I have an ast-can485 board. I built it into an electric vehicle last year, (April 2019) and it’s been working fine. Recently, I wanted to update the program, but I get the following error when I try to upload the program:

avrdude: verification error, first mismatch at byte 0x0000

0x14 != 0x0c

avrdude: verification error; content mismatch

avrdude: verification error; content mismatch

I tried uploading some very simple test programs including the sample code from Sparkfun but I always get this same error.

Nothing has chanced on my end. Same computer, same cables etc.

I did some research and saw something about bootloader but I’m not sure exactly how to fix this problem. I see someone else reported the same error with this same board but didn’t get a reply. I see a few other posts regarding this error but with other hardware and they don’t make a lot of sense of to me.

I turned on verbose mode and I can see the program uploads fine; I see the lights flash but the verification fails. After the message included above it says:

the selected serial port

does not exist or your board is not connected

But that can’t be correct. The program uploads OK and I see the lights flashing etc.

Does anyone know what might have happened and how it can be fixed? Any help is greatly appreciated.

Hello, did you ever get this fixed? I am having a similar issue on my side.