Several years on a coin cell?

So far, the power consumption of the rotary encoder node has been optimised by taking the current draw from 5.0 mA to 45 µA - that’s an estimated coin cell battery life of 6 months. Unfortunately, this is where diminishing returns start to kick in. To progress beyond this point requires rethinking the node’s logic. We need to put the µC into a really low-power mode, in such a way that it’ll still wake up every time that control dial is touched.