Author Topic: ATmega8 stopped responding ! (Read 1023 times)

Swaroop 21 · « **on:** July 22, 2024, 11:18:46 am »

I have a Atmega8 on a sensor board which contains a Accelerometer (MMA7361L). The ATmega8 doesn't have any crystal osc. and when I first soldered it, I burned the bootloader using a USBASP programmer for running on internal 8Mhz Freq. and uploaded a simple ADC sketch to print the X,Y,Z values. It worked fine but then the other day I was playing around with ATMega328PB and then I switched back to my sensor board with ATmega8, got in the tools section and I believe that when I burn the bootloader again it defaulted to its normal configuration i.e. External 16Mhz in the tools option and I didn't catch it which after that it stopped responding. I tried to burn the bootloader again and it said no target found. I haven't burnt any wrong bootloader. I used the MiniCORE boards manager. Is there a way to retrieve it without the external crystal or is there other problem which can't be fixed ? I don't think I killed it as I didn't misconnect anything. So what can be the reason for it to not detect neither burn a bootloader.

mikerj · « **Reply #1 on:** July 22, 2024, 12:28:55 pm »

After programming the fuses for an external clock you will need to apply a clock to the XTAL1 pin to enable any further programming. It doesn't need to be a crystal or resonator, you could use e.g. a 555 timer or use your Mega328 to supply a suitable temporary clock until you reset the fuses to the correct value. You must set the programmer clock to 1/4 or less of the AVR clock frequency e.g. if you apply a 1 MHz clock, set the USBASP to 250kHz or lower.