e024576

Thanks. While I know the method isn't completely representativre of "real world," it's still seems useful.

A Raspi zero is $5 at Micro Center near me and clone Camera module about $7 on AliExpress.

I estimate cost at $30-$50. The work was done over several weeks with a good deal of trial and error. I replicate is probably a weekend project,

A Raspi zero is $5 at Micro Center near me and clone Camera module about $7 on AliExpress. The advantage of the Alarm clock is that it come with display and buttons for setting alarm. The RTC module module was only $1.5. I couldn't figure out how to "share" RTC between both Attiny85 and Pi. Your point regarding quiescent current is a good one, but I rarely it included in battery life estimates. Thanks for optics improvement suggests.

The robot only takes one shoot at each tumbler and since it does not have a vision system, it won't detect a miss or take a second - that is an open loop control system. I practice the robot, once calibrated, rarely misses.

Done, see step 2.