Bitcoin miners and a hot-tub controller

Designed and built the controller · 2022 · Archived

An investor wanted to run Bitcoin miners at home. I designed the controller box and wrote the software that ran the rig. Part of that software was a control program to keep a hot tub at a set temperature with heat from the miners.

The open controller box from above: DIN rails, relays, power meters, a Raspberry Pi and red wiring. — Inside the controller box.

A 50-amp outlet and two smaller outlets on the side of the box, each with a live volt and amp readout. — The outlets that fed the miners, each with its own meter.

A red emergency stop button in a yellow housing, cabled to the side of the box. — The emergency stop, on its own cable.

Sealed HDMI, USB and Ethernet ports on the side of the box, one cap held open. — Sealed data ports for the controller inside.

Hardware

The controller was a sealed electrical box with DIN rails, relays, power meters and a Raspberry Pi inside. I wrote the drivers the Pi used to read a water flow sensor and switch the relays. An emergency stop sat outside the box on its own cable.

Software

Controller nodes written in Python talked to each other over an IRC server I ran for the rig, using a message format I wrote. They pulled stats from the miners over SSH and wrote their readings to InfluxDB. A GraphQL API fed a Next.js dashboard.

The dashboard had one knob, for the water temperature. The default was 104°F.

Stack

Languages: Python
Product: Next.jsGraphQL
Data: InfluxDB
Hardware: Raspberry Pi

← All work ← Previous: Flipside Next: SpamCntrl →