Turning an Arduino of virtually any sort into a simple AVR 6-pin ISP programmer is old hat. But when Atmel came out with a series of really tiny AVR chips, the ATtiny10 and friends with only six pins total, they needed a new programming standard. Enter TPI (tiny programming interface), and exit all of your previously useful DIY AVR programmers.

[Kimio Kosaka] wrote a dual-purpose TPI and ISP firmware for the ATmegaxxUn chips that are used as a USB-serial bridge on the Unos, and constitute the only chip on board a Leonardo or Micro. The catch? You’re going to have to do a little bit of fine-pitch soldering. Specifically, [Kosaka-san] wants you to get access to an otherwise obscured signal by drilling out a via. We’d do it just for that alone.

The rest of the procedure is to flash a DFU USB bootloader into the Arduino, then load up the flash-programmer code. Your former Arduino is now capable of flashing both old-school ISP AVR chips, as well as the tiny little ones that require TPI.

If you’re having deja vu, yes we have covered a DIY TPI programmer before, but it required a bespoke uploader software on your host computer. [Kosaka]’s version appears to the host as an Atmel programmer, and you can use any of the standard tools. And you get to try your hand at some fun fine-pitch solder work. That’s win-win!

The ATtiny10 – along with its younger siblings that go by the names ATtiny 4, 5, and 9 – are the smallest microcontrollers Atmel makes. With only 32 bytes of RAM and 1 kB of Flash, there’s still whole lot you can do with this tiny six-pin chip. [feynman17] figured out a way to program this chip using an Arduino, allowing him to throw just about anything at this absurdly small microcontroller.

The ATtiny10 doesn’t use the familiar ISP programming header found on other Atmel-based boards. Instead, it uses the exceedingly odd Tiny Programming Interface to write bits to the Flash on the chip. [feynman17] realized he could use the Arduino SPI library to communicate with this chip and built a small programming shield with just a few resistors and a 8-pin DIP socket to mount an ATtiny10 breakout board.

After writing a sketch to upload a .hex file from the Arduino serial console, [feynman] had a programmed ATtiny10, ready to be dropped into whatever astonishingly small project he had in mind.

As for what you can do with this small microcontroller, chiptunes are always an option, as is making a very, very small Simon clone. It may not be a powerhouse, but there’s still a lot you can do with this very inexpensive microcontroller.