now i have a strange problem.
Two boards with M128 assembled i wanted to reprogram using a serial programmer - all like i´m doing every day. (I´m no nobee)
I erased the AVR´s and wanted to reprogram it. This failed.
Because the program doesn´t run anymore i think they are erased.
every time i want to access the AVR the avrisp says "not accessable - check power and clock..."
power is OK, connection is OK.
So my first thought was that the fuse bits are wrong.
But I can´t read the bits.
When i check the device ID then it says "000102". that´s wrong, it must be "1E...." after every 10-20 tries it shows the correct ID. Once.
After RESET the ID is (almost?) allways correct.
So i tried immediately after reset to program the fuse bits. The AVRISP says that programming was OK. (So it must have been a good communication- or not? When i disconnect and try to programm it gives an error)
I thought of a bad connection. But with a third board (i dont like to erase until the problem is solved) i have no communication problems. I can read everything.
I tried AVRISP and AVRDUDE. - no change
I changed the cable. no change
I can read the device ID only once immediately after reset.
I tried to supply the AVR with external clock - no change.
What else can I try??
Thanks alot for your ideas.