Microcontrollers are small, no one is arguing that. On a silicon wafer the size of a grain of rice, you can connect a GPS tracker to the Internet. Put that in a package, and you can put the Internet of Things into something the size of a postage stamp. There’s one microcontroller that’s smaller than all the others. It’s the ATtiny10, and its brethren the ATtiny4, 5, and 9. It comes in an SOT-23-6 package, a size that’s more often seen in packages for single transistors. It’s not very capable, but it is very small. It’s also very weird, with a programming scheme that’s not found in other chips from the Atmel/Microchip motherbrain. Now, finally, we have a great tutorial on using the ATtiny10, and it comes from none other than [Ben Heck].
The key difference between the ATtiny10 and other AVRs is that the tiny10 doesn’t use the standard AVR ISP protocol for programming. Instead of six pins for power, ground, MISO, MOSI, SCK, and RST, this is a high-voltage programming scheme that needs 12 Volts. The normal AVR programmer can do it, but you need to build an adapter. That’s exactly what [Ben] did, using a single-sided perf board, a lot of solder, and some headers. It looks like a lot, but there’s really not much to this programmer board. There’s a transistor and an optocoupler. The only thing that could make this programmer better is an SOT-23 ZIF socket. This would allow bare tiny10s to be programmed without first soldering them to a breakout board, but ZIF sockets are expensive to begin with, and the prices on SOT-23 sockets are absurd.
Programming the device was a matter of loading Atmel Studio and going through the usual AVR rigamarole, but Ben was eventually able to connect a light sensor to the tiny10 and have it output a value over serial. This was all done on a device with only 32 Bytes of RAM. That’s impressive, and one of the cool things about the smallest microcontroller you can buy.