Windows Drivers

For windows, we use a modified LibUSB driver. You can download it here:

For historic reasons, we have a:

  • Windows USBtinyISP driver built with libusb v1.10. Use this for older WinAVR's. Don't use this unless you have to interface with old versions of software that are bound to libusb v1.1


AVRDUDE is the recommended software to use if you want to program/flash an AVR microcontroller, here are compiled binaries with the patches and USB support:

    • The latest version of WinAVR has avrdude v5.5 with usbtinyisp support so just install that! (Detailed instructions are here)
      Make sure that you have the v1.12 driver installed not the v1.10 or you'll have problems.
    • Mac OS X PPC binaries version v5.4
      Copy avrdude.conf into /usr/local/etc and avrdude into /usr/local/bin
    • Mac OS X Intel binaries version v5.4
      Copy avrdude.conf into /usr/local/etc and avrdude into /usr/local/bin
    • Patched Source code for Mac, Linux or other unixy machines.
      You can just grab avrdude 5.5 which supports usbtiny out of the box! Detailed instructions are here

To compile avrdude for your own machine, first make sure you have libusb (and libusb-dev) installed. You can use fink (on a Mac) or apt-get or download it from sourceforge. Whatever, just try to get a recent version.

Next, decompress the source code and open up a terminal window. cd to the directory and type in ./configure or sh configure and look for a line that scrolls by with something like checking for usb_get_simple_string in -lusb... yes. If you see it then libusb was properly detected.

Sometimes, for unknown reasons, libusb is installed but it is not detected. In this case, after configure is done, edit the Makefile in the same directory.

Look for the line starting with LIBUSB = and change it to LIBUSB="-lusb" if you're on a MacOSX machine change it to LIBUSB="-lusb -framework CoreFoundation -framework IOKit"
Next, edit ac_cfg.h and look for the line /* #undef HAVE_LIBUSB */ and underneath it add #define HAVE_LIBUSB 1

If you and then ./make and then sudo ./make install it will place avrdude in /usr/local/bin and avrdude.conf in /usr/local/etc

Hardware/Firmware Files for v2.0

The latest!

Please note this firmware contains the Adafruit VID/PID, while the firmware is open source the VID/PID is not. To use in your own products, replace those values in usbtiny.h You can purchase a USB VID for yourself at

Hardware/Firmware Files for v1.0

The board design is not single sided, but it's close: you will need to solder in the 5 wires that would go on the top. I have successfully toner-transfer etched this design.

v1.04 is a possible hotfix for some flakiness, you can try either one.

USBtiny500 compatibility bridge for AVR Studio

Download the latest installer
And source code

This guide was first published on Jun 10, 2013. It was last updated on Jun 10, 2013. This page (Download) was last updated on Jan 25, 2020.