MycroStartElectronics

MicroCool 2.0 temperature controller

Keep it cold.
Keep the coil clear.

MicroCool 2.0 runs your air conditioner, compressor or heater from two temperature probes. It holds a walk-in cooler, fridge or heated room where you set it, and stops cooling before the coil can ice up.

  • 2 probesRoom air and the AC's fins
  • 30 APower relay at 240 VAC
  • SD cardTemperature logs, one file per day
  • No cloudIts own hotspot and your home Wi-Fi

Why MicroCool

Everything a cold room needs. Nothing it doesn't.

Two probes, one big relay and firmware that knows when to rest. Set it up once and it gets on with the job.

Fin protection

A second probe on the air conditioner's fins stops cooling before the coil ices up, and waits for it to warm before starting again.

Cool or heat

Run a walk-in cooler, fridge or freezer, or switch to Heat mode for a greenhouse, coop or shop.

Compressor rest

A minimum rest between runs, from 0 to 120 minutes, so the compressor isn't short-cycled.

Weekly schedule

Up to 8 time windows a week, set from the web app. Timer mode runs the output for a set time.

Wi-Fi web app

Its own hotspot and your home Wi-Fi at the same time. Live temperatures and settings on any phone.

SD card logs

Temperatures are saved to the SD card, one CSV file per day, ready to open in any spreadsheet.

Fails safe

If a probe stops answering, the output turns off and the status light blinks red until it's back.

Safe updates

Update over Wi-Fi or from the SD card. A new version checks itself and rolls back on its own if something is wrong.

How it works

Two probes. One simple rule.

The room probe decides when to cool. The fin probe decides when to stop, before the coil frosts over.

  1. Probes

    One hangs in the room air. The other clips into the air conditioner's fins.

  2. MicroCool

    Checks both against your four setpoints ten times a second.

  3. 30 A relay

    MicroCool's 12 V output drives the coil of the power relay.

  4. Your AC

    The relay switches the air conditioner, compressor or heater.

Starts

when the room is above Room high and the fins are above Fin high, once the compressor has rested.

Stops

when the room drops below Room low or the fins below Fin low. In between, it keeps doing what it was doing.