USBtinyISP Frequently Asked Questions
I'm running avrdude and I get "Initialization failed, rc=-1"

This response from avrdude means that it can talk to the programmer but the programmer can't talk to the chip.

Most of the time, your programmer is working fine, check your cables and pins and that the target device is properly wired up. We have never encountered a USBtinyISP that got to this point where it talks to the computer but not a chip and it is the kit that is defective. It is ALWAYS a bad chip or a wiring, clocking, bit-speed, powering or output-resistor problem

Its not working!

Check:

before posting to the forums!

I'm running avrdude and I get "USB read error: expected 4, got -1" (or something similar

There's a priv's problem, check the usbtinyisp avrdude linux instructions for more info

My 64 bit computer doesn't seem to work!

Thanks to intrepid assistants, a patch has been submitted to avrdude project, if you want to fix it yourself, simply replace the lines in usbtiny.c in avrdude that have
sizeof(res)
with
4

Ill try to get this patched for the next rev. Sorry! This has been fixed! Hurrah

I'm having trouble compiling/burning the chip for this project...

Use the precompiled .hex file and Makefiles as newer avr-gcc compilers may not be able to squeeze the code down to fit in the chip. Modify the Makefile in spi as needed and, in the spi folder, type in "make fuse flash" Beyond that, you're on your own!

I'm running avrdude and I get "Could not find USB device 0x1781/0xc9f"

This response means it could not find the programmer. There are many possible reasons:

  1. If you are using the latest WinAVR (which was built with an old version of the libusb driver library) you must use the v1.10 driver. Uninstall the driver you have and make sure you get the right one installed.
  2. Try unplugging and re-plugging it in
  3. Make sure the driver (windows only) is installed.
  4. Make sure the green LED is lit (which means its powered and has performed USB enumeration).
  5. Make sure you have libusb installed and that it is the correct version. (linux/mac)
  6. Make sure you have replaced the old version of libusb0.dll with the one from the download page.
  7. Make sure you are not providing power to the target through USB when it already has power. Check the jumper in the end of the device and remove it, if so.
  8. If you programmed the usbtinyisp chip, make sure the fuses are set properly
I'm having trouble building this project from scratch...

Beyond that advice, if you can't get this project working on your own I suggest buying a kit.It's not a simple project to debug!

I'm running avrdude and I get "error at avrdude.conf:370 unrecognized character: 'u'"

This means you properly replaced avrdude.conf but did not replace avrdude.exe (or under mac/linux, just avrdude) do a search on your computer and verify that you have replaced any copy of avrdude.conf with the patched version from the download page.

I'm running avrdude and I get 'avrdude: Can't find programmer id "usbtiny"'

This means you did not replace avrdude.exe (or under mac/linux, just avrdude) with the patched version. Do a search on your computer for avrdude.exe and verify that you have replaced any copy of avrdude with the patched version from the download page.

March 15, 2010 14:06