Hello guys,
I recently blocked an atmega328p by setting the wrong fuse, after much googling around i found this https://mightyohm.com/blog/2008/09/arduino-based-avr-high-voltage-programmer/, Jeff has made an awesome cheap recovering tool and is selling the thing all build, but i only built the first version and downloaded the .pde file for arduino.
I built this since i had all the material around and don't want to wait ordering one, the only thing i didn't had was the transistor, i replaced the 2N3903 for a BC546 and checked all connections and also changed on the source code the HFUSE to match the default atmega328p, my circuit has nothing wrong but still doesn't work, when i pressed the button the light goes off and cames after a while so aparently the behaviour is whats expected.
I would like to know if someone has built this and experienced any problem ? also im using the Arduino Duemilanove.
Look at the pins on their datasheets:
1) The pins on the 2N3903 are lettered E, B, C.
2) The pins on the BC546 are lettered C, B, E.
Connected backwards, the emitter-base junction might be fried.
Well, sorry for the post since i tested it again and it is working , i was aware of the pinout of the bc546 but its a good point Audioguru, i believe the problem was maybe my 12V power supply current limit was in the minimum even thought this circuit is not really consuming much current.
Anyway i can confirm the circuit and the arduino sketch works like a charm .