The current state is *mostly* hardware complete, but software is in early stages (read: test mode).

The uC is an ESP8266,

Outputs:

Three relays for controlling outputs: 2x 10amp relays for pump and valve, 1x 30amp for the heater. (The 30amp is overkill, but was the best price for a DPDT, to totally isolate the heater when off).

Inputs:

Three DS temperature sensors on a single bus. (Ambient, exit, return).

Two float sensors - For low (top-up), danger low (shut-down all systems).

I found a PSU in my parts bin that outputs 3.3v, 5v and 12v - perfect!

I cut a mounting-plate from some scrap perspex, mounted the PSU, relays and wiring blocks and controller.

My next goals/steps:

- Field test the base inputs/outputs.

- Finalise the 'admin override' section for self-contained control.

- Write a DB controlled monitor (so the web interface can program the controller for times, etc).