Recently I have got some ATMEGA8L chips that cannot be read nor programmed through USBASP. I was wondering whether these chips are usable or totally broken.
I have read the datasheet of chip and realized that the chip may not be able to read if it is locked and/or the fuse settings are wrong.
It also mentioned that High Voltage Parallel Programming (HVPP) can be used to rescue the chip. Therefore I build this to test it out.
You can make one to rescue your chips as well.
Step 1: Build the Circuit
You need following items:
1. One working ATMEGA micro controller (ATMEGA8/88/168/328, I have used a ATMEGA168PA board)
2. One 28 pins DIP socket for the target chip (You may use ZIP socket if you have one)
3. One NPN transistor (2N3904 or 2N2222 etc, I have used 2N3904 here)
4. Two 1K resistor
5. One 150R resistor (To limit current for red LED, you need 100R for green or blue LED)
6. One LED for +12V indicator (I have used red LED)
7. A 12V battery (A23) or a step-up module (I have used MT3608 step-up module in this project)
Solder them all together based on the Schematic.
Step 2: Program the Configurator Micro Controller
Load the source code in Arduino IDE, select your board and update the chip.
Or you can program the chip directly by using my pre-compiled HEX files.
Step 3: Configure the Problem Chip
Now, everything is ready. It is time to fix the problem chip.
You can use command through the Serial Monitor in Arduino IDE (BAUD 57600) to configure the chip. The full menu can be found inside the Arduino source code.
Alternatively, you can use the windows GUI to communicate with the configurator. The GUI has included all the functions that the configurator provide.
You may download the executable file or source code from my github and compile it yourself.
Step 4: Final Words
I have successfully rescue these un-readable chip and they all working fine after I have erase the chip and reset the fuse settings.
You can fix your problem chips as well.
To get more information and the full source code for the project, please visit my github.