March 25, 2023

In a super sensible residence, the explosion of low-cost WiFi and Bluetooth chips has allowed a whole bunch of small wi-fi units to regulate the switches, lights, and all the things else required for a “sensible residence” at a comparatively low value. However what in the event you don’t need a whole bunch of internet-connected units in your house polluting the wi-fi spectrum and permitting potential safety holes into your community? If you happen to’re like [Lucas Teske], you may attain for one thing wired and use cheap and (currently) available Raspberry Pi Picos to create PicoHome.

The distinctive twist of PicoHome is that it makes use of a CAN bus for communication. One among [Lucas’] targets was to make the boards simply swappable when {hardware} failed. This meant board-to-board communication and protocols like I2C had been vulnerable to noise (each time a relay triggered, the bus would lock up briefly). The CAN bus is designed to work in an electrically noisy atmosphere.

There are two elements to the system: pico-relay and pico-input. The primary connects to a 16 relay board and may management 16 completely different 24v relays. The second has 16 optoisolators to learn from 12v-24v switches and varied buttons all through the home. These might be positioned in an enormous metallic field in a central wiring location and never fear about it.

The firmware and board files are all launched underneath an Apache 2.0 license, however the CAN2040 library this mission depends on is underneath GPL. We lined the CAN2040 library when it was first launched, and it’s beautiful to see it getting used for one thing totally surprising.