Summary of AVR High Voltage Programmer Using Arduino AVR microcontroller
AVR microcontrollers use fuse bits to configure features like the watchdog timer and internal oscillator speed. Most fuses can be toggled via SPI programmers, but some—such as RSTDISBL—cannot be reversed that way. If RSTDISBL is set, the chip requires a high-voltage programmer (e.g., STK500) to restore functionality. An alternative is building an AVR High Voltage Programmer using an Arduino, as demonstrated by Jeff Keyzer; the recovery process is straightforward.
Parts used in theAVR High Voltage Programmer Using Arduino:
- Arduino (as HV programmer controller)
- AVR microcontroller target chip
- Resistors
- Capacitors
- Transistors or MOSFETs (for high-voltage switching)
- Zener diode or voltage regulator (for protection)
- High-voltage supply (12V)
- Connecting wires and breadboard or PCB
- ISP header or socket for target AVR
AVR microcontroller uses fuse bits to set its operational parameters like watchdog timer settings and change speed of the internal oscillator. Most fuse bits can be set or reset without worry. You can flash it into one state and then flashed back again using an SPI programmer.
However, some fuse bits like RSTDISBL fuse are irreversible using SPI programmer. Once the RSTDISBL fuse is set you need a high voltage programmer like the STK500, which is costly, to bring alive the chip. If you don’t have STK500 you can try to build your own AVR High Voltage Programmer using Arduino like Jeff Keyzer did. The recovery fuse programming process is easy.
For more detail: AVR High Voltage Programmer Using Arduino AVR microcontroller
- What are fuse bits used for in AVR microcontrollers?
Fuse bits set operational parameters like watchdog timer settings and internal oscillator speed. - Can most fuse bits be changed with an SPI programmer?
Yes, most fuse bits can be set or reset using an SPI programmer. - Which fuse is irreversible using an SPI programmer?
The RSTDISBL fuse cannot be reversed using an SPI programmer. - What is required to recover an AVR with RSTDISBL set?
A high-voltage programmer such as the STK500 is required to recover the chip. - Is there a low-cost alternative to the STK500?
Yes, you can build an AVR High Voltage Programmer using an Arduino as demonstrated by Jeff Keyzer. - Is the recovery fuse programming process difficult?
The article states that the recovery fuse programming process is easy.
