使用AVR Pocket Programmer时USBTiny/AVRDude初始化ATMega2560失败

Let's work through the issue you're hitting with your custom ATmega2560 board and Sparkfun AVR Pocket Programmer. First, let's recap your setup and the error you encountered:

You built a custom board with a brand-new ATmega2560 chip, then tried programming it via USBTiny/AVRdude using this command:

avrdude -c usbtiny -p atmega2560 -v -v -v

Which threw this error:

avrdude: programmer operation not supported
avrdude: Using SCK period of 10 usec
CMD: [ac 53 00 00] [00 00 00 00]
CMD: [ac 53 00 00] [00 00 00 00]
avrdude: initialization failed, rc=-1
Double check connections and try again...

Here are the most likely fixes to try, ordered by how easy they are to test:

1. Verify Hardware Connections (Most Common Fix) #

• Double-check ISP pin mapping: Every pin on the Sparkfun Pocket Programmer must line up exactly with your ATmega2560:
  • MISO ↔ MISO
  • MOSI ↔ MOSI
  • SCK ↔ SCK
  • VCC ↔ 5V (ATmega2560 is a 5V chip—don’t feed it 3.3V!)
  • GND ↔ GND
  • RESET ↔ RESET (this pin is critical for programming and easy to miss)
• Inspect solders: Custom boards often have cold joints or bridged pins. Use a multimeter to test continuity between each programmer pin and the corresponding ATmega2560 pin.
• Add external power if needed: If your board draws more power than the programmer can supply, hook up an external 5V power source to your board (just make sure GND is shared with the programmer).

2. Adjust AVRdude Settings for Compatibility #

• Lower the SCK clock speed: Your custom board might have longer trace lengths or a slower clock source, which can break communication. Add the -B flag to reduce the SCK period—start with -B 2 and increase if needed:

  avrdude -c usbtiny -p atmega2560 -v -v -v -B 2
  

• Update AVRdude: Older versions of AVRdude can have limited support for ATmega2560 with the USBTiny programmer. Grab the latest version and try again.

3. Check ATmega2560 Fuse Settings #

If your chip has incorrect fuse bits (e.g., set to use an external crystal that’s not soldered, or ISP programming is disabled), it won’t respond to the programmer.

• Try reading fuses with a slower clock: Use -B 10 to give the chip more time to respond:

  avrdude -c usbtiny -p atmega2560 -v -U lfuse:r:-:h
  

• Reset fuses to factory defaults: If reading fails, you can try setting fuses to their default values (assuming you’re using the internal 8MHz clock):

  avrdude -c usbtiny -p atmega2560 -U lfuse:w:0xff:m -U hfuse:w:0xd8:m -U efuse:w:0xfd:m
  

  Note: Double-check fuse values for your specific clock setup before running this—wrong fuses can brick your chip.

4. Rule Out Programmer or USB Issues #

• Switch USB ports: USB 3.0 ports sometimes cause compatibility problems with low-speed devices like the USBTiny programmer. Try a USB 2.0 port if available.
• Test the programmer on a known-good board: If you have another AVR board (like an Arduino Uno with ATmega328P), use the same programmer to program it. This will confirm if the programmer itself is faulty.

内容的提问来源于stack exchange，提问作者Rayaarito