A weblog focused on interesting circuits, ideas, schematics and other information about microelectronics and microcontrollers.
Arduino-based AVR High Voltage Programmer
How to "unbrick" bad fused AVR? You need an AVR high-voltage programmer. Build your own with an Arduino.
When you're programming an AVR with SPI (called Low-voltage, LVP or in-system), you should disable the RESET pin. This makes the device impossible to reflash with SPI. This is particularly frustrating because the device is still 100% functional, just completely deaf to ordinary serial programmers. The only way to recover the device is using what Atmel calls “High Voltage Parallel Programming Mode” which very few programmers support.
Here is a cure for this situation: A simple high-voltage fuse unblocker.