Thinking of a new gadget...

[Csory_imp]

Csory good idea to let the members choose,it should be something intuitive and simple i would be for A, meter sweep, off for 2 seconds, meter sweep, off 2 sec and on to start and ride or something like that.

Chances are you will do this only once and leave it in the same state forever so no biggy if you save the setting in memory on power down.

it should be obvious but you could have an F or C after the toggle to confirm if that is easy to implement on the display.

Are you planning on a fancy rat race display routine like the windows balls as a wakeup message? not sure how you go with the memory capacity.

Is the light sensor high/low or a/d ?

Now that you mention it... something silly could be done Will fill up remaining progmem with an eye-candy

Ambient sensor is analog, just a few dozen steps though (due to shared rst pin - cound be inhibited and AD res up to full 10 bits, once the code is final).