So the surprise chip, ATtiny10, arrived, and I started to work on programming it. I already have the code for it prepared, and the PCB has been ordered a week ago, so I just need to get the code on the chip somehow.

The ATtiny10 is not like the larger ATtinys -- it doesn't use ISP (aka SPI) for programming, but instead uses something called TPI (tiny programming interface), which seems to be something like half-duplex SPI. When I was upgrading my USBASP programmer, I noticed that the firmware has added support for TPI, and that it's already in AVRdude too, so it should be simple, right?

I soldered the tiny chip to a breakout board (the last row of pins uses two pads, because the alignment wasn't quite right, but the connections are good), I connected my programmer according to the schematic I found on some Polish blog (good thing I know the language) at http://mirekk36.blogspot.ch/2013/07/attiny10-tpi-usbasp-mkavrcalculator.html and I proceeded to upload the hex file with:

avrdude -c usbasp-clone -p t10 -U flash:w:main.hex:i

The result? Of course the well known and loved message error:

avrdude: error: program enable: target doesn't answer.
avrdude: initialization failed, rc=-1
         Double check connections and try again, or use -F to override
         this check.

I tried with different clock speeds, with the "slow clock" jumper, I disconnected and reconnected the whole thing several times, I measured the resistances. It all checks. Should work. Doesn't.

I even made a side trip to try and program it with a CP2102 USB2TTL, which AVRdude apparently can do, but that didn't work either.

So now I'm sitting here after a whole day of trying to program this thing, looking at it, and considering giving up.

If anybody has any experience with this, or some suggestions for things to try, I'm open for ideas.