I agree, the CPU is probably the smallest problem. I'm curious with how little power you can get away with using a BLE radio. Especially if you constrain yours

I agree, the CPU is probably the smallest problem. I'm curious with how little power you can get away with using a BLE radio. Especially if you constrain yourself to some kind of polling mode where the watch reaches out to the smartphone every minute or 5 minuetes or so.