I got my wife this Accolmile Antelope 1S electric bicycle with Bafang components from their latest M-series lineup of mid-drive motors and displays which communicate over a CAN bus. It’s a grea...
Makita doesn’t make an official USB-C PD (power delivery) adaptor (they only have ADP05 with two 5V/2A ports) so I found this UDCB094 on AliExpress (affiliate link) with PD65W output and with v...
https://kaspars.net/blog/usb-c-pd65w-adapter-charger-18v-20v-batteries
Meshtastic is a wonderful project for creating decentralised text-based communication networks for local communities using low power (and low cost) Lora radios. Fun fact — the Meshtastic logo a...
I’ve always wanted a rack mount UPS for all of our homelab gear, and PowerWalker VI 500 was pretty much the cheapest option at EUR 192 at the time. Here are my notes and observations after havi...
For a home server hosting mostly Docker containers I’ve always wanted a computer with proper and multiple disk drives for data redundancy instead of SD cards used by most single-board computers...
Until recently Zemismart ZMHK-01 was the only Zigbee hub with Apple HomeKit integration. Now there is also NEO NAS-ZW05B0 Zigbee hub (affiliate link) with a HomeKit integration produced by Shenzh...
https://kaspars.net/blog/neo-nas-zw05b0-tuya-zigbee-homekit-hub
It is a single unit for ventilation with heat recovery and a heat pump against the exhaust air for heating or cooling the incoming air and producing domestic hot water, and another heat pump agai...
These are two devices with identical PM2.5/PM10 sensors (boxes with the metal cover), temperature and humidity sensors (top center) which are connected to an STC 8G1K08 microcontroller which prep...
https://kaspars.net/blog/tuya-smart-box-house-keeper-air-quality
Zemismart ZMHK-01 is one of the few hubs that is compatible with Apple HomeKit and can expose non-HomeKit Zigbee devices in the Home app similar to the Aqara G2H camera hub. Behind the scenes it ...
Hiking DDS238-2 ZN/S is a cheap €25 single phase energy meter which can measure import and export energy in addition to all the standard parameters, and has a Modbus interface over RS485. I use...
Aqara G2H (ZNSXJ12LM) is a really nice Zigbee hub and indoor camera with official HomeKit support. Of course it runs Linux so people have discovered ways to connect it to Home Assistant which exp...
As part of an experiment to add domestic water heating capabilities to conventional mini-split ACs, I purchased an air-source heat pump Gree GWH09YD-S6DBA2A which has an inverter controlled compr...
MySensors is a great project for building IoT devices but it tries to do many things — define a general serial communications protocol (similar to ModBus, CAN), provide a software library for m...
Mini split air conditioners are great little air-source heat pumps that can work in the reverse and provide heating to the building, too. For highly insulated houses built according to the Passiv...
Lollette LE3U is a “copy” of the Mitsubishi FX3U PLC for $60 on AliExpress while the original costs around $1000. All configuration is done using Mitsubishi’s proprietary software GX Develo...
Update: The protocol is now well understood and supported by the Neolink RTSP bridge software and this fork of the Camera Proxy project. Battery powered cameras from Reolink offer remote viewing ...
https://kaspars.net/blog/reolink-battery-camera-remote-protocol
I bought this UseeLink water/gas valve which according to the casing was supposed to be SM-AW713Z with the Zigbee radio but is actually SM-AW713 with a Tuya TYWE3S WiFi radio. No wonder it wasn�...
This is an attempt at reverse engineering the communication protocol used by the Zehnder ComfoSpot 50 ventilation unit with heat recovery. It has the following control board: The “BUS X7” has...
Here are the photos of the Sonoff Si7021 temperature and humidity sensor which uses the Silicon Labs Si7021 sensor attached to the Silicon Labs EFM8BB10F2G-QFN20 microcontroller. The other side o...
Single channel LoRaWAN gateways are great for getting started with the LoRaWAN networks and actually sending some data from your sensors to the Things Network and other hubs. I built mine with Ho...
Aranet4 is a wireless CO2, temperature and relative humidity sensor with Bluetooth LE connectivity (made by SAF Tehnika) which is supported by the Sensor Pilot web app. It appears to be using the...
Did you know that Chrome-based browsers (including on Android phones) can interact with Bluetooth Low Energy (LE) sensors and devices without any additional software using the Web Bluetooth API? ...
Did you know that most of the action cameras (GoPro, DJI Osmo, Akaso, EKEN, SJCAM, Xiaomi and ThiEYE) use the same lens mount? It’s called M12 or S-mount which stands for the 12 millimeter thre...
Update: this project was featured in issue 92 of the official Raspberry Pi magazine (download as PDF, buy the issue or subscribe). SSH-ing into a remote solar powered Raspberry Pi at the top of a...
MicroPython is awesome! Before working with Wemos D1 mini modules (which are awesome) I had only written C (mostly for AVR chips) and some Arduino sugar which was hard to get around and organize ...
Reduced power usage is the main reason for building custom boards with ESP8266 since most of the modules such as Wemos and NodeMCU use power regulators and UART to USB chips that draw a lot more ...
Reading and processing button presses with microcontrollers is a lot harder than one could assume because of the signal noise for which we have hardware and software solutions. I couldn’t find ...
I want to design a wireless light switch that works for years without charging and doesn’t require mains connection and provides complete flexibility over the set of devices it controls. The ac...
Switching things off and on again is one of the main features of home automation. It is usually achieved through electronic switches or relays that are controlled by NPN or PNP transistor outputs...
The KEY-ID FIDO U2F security keys are a nice alternative to YubiKey 4 Nano because they cost only $12 instead of $50. However they include a green LED that is always enabled which makes it unsui...