Still waiting for Arduino Zeros to come in so I can fulfill the Kickstarter. While the Kickstarter was running the PCBs for my smart Nest like thermostat came in. I've built up the first board and now it's time to start writing some software.
So here's a more complete picture.
Upper left ESP8266 for WiFi connection -- will sync up to time, and also post data, For my use I don't really need to remotely control it, but I will add that feature.
Next to that to the right, big cap and switching regulator to convert 24V AC to 5V
Below that LCD display, and up down switches.
Then the ARM stamp, and temp sensor in lower left.
To the right of the ARM stamp, battery charge regulator and op amp to measure battery voltage. That red wire, I should have read the spec sheet more carefully. The battery charge regulator does not have an automatic shutoff, so the ARM stamp will have to do that by monitoring the battery voltage.
And the white battery connector (battery disconnected for now, but I did see it charge my 1 Ah battery up to 4.1 V). Which also means it passed the initial smoke test.
More details on this project at the forum.