The Unifi Protect G4 Doorbell

Posted on Sun 12 June 2022 in reverse-engineering

I've been dragging my feet for years to get a video doorbell. I wanted a doorbell that "just works" as a doorbell, even if the WiFi is down, and I didn't want my video footage to be stored in the cloud, but only accessible when on the local network, either …


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Reverse engineering the Mitsubishi heat-pump WiFi adapter

Posted on Sat 04 June 2022 in reverse-engineering

Recently we had a heat pump (A/C, air conditioner, AirCon) installed. The indoor units came with the usual IR remote, but they also had a built-in WiFi module along with a smartphone app to control them from anywhere. I'm not a big fan of connecting home appliances to clouds …


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Backups

Posted on Wed 04 May 2022 in sysadmin

Recently I was rethinking my off-site backup strategy. Ever since Amazon AWS launched their Glacier Deep Archive storage tier, it looked really interesting for backup use-cases. For starters, it's super cheap to keep your bytes around: $1.01376/TiB/month in most regions as of this writing. I haven't found …


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Surviving Mars

Posted on Mon 11 April 2022 in games

I discovered another game that gives me an excuse to write silly calculator modules: Surviving Mars. Some random notes and a few tools I wrote, or interesting tools I found online:


Kerbal Space Program

Posted on Wed 25 August 2021 in games

I am usually late to proverbial parties, but I think I’ve outdone myself by discovering the computer game Kerbal Space Program roughly 10 years after it first became playable. It’s the kind of game that triggers my “I’ll optimize this by writing a script”, so here are …


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Monitoring network bandwidth of individual hosts from the router

Posted on Sat 28 November 2020 in monitoring

I live in a part of the world where broadband internet subscriptions come with a monthly data cap. The datacap is relatively large (750GB/month), but streaming 4k content will get you there! So I wanted to keep taps on my data usage. My router is the ideal place to …


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Cumulative graphs in Prometheus

Posted on Sun 16 August 2020 in monitoring

I've been experimenting a bit with Prometheus and Grafana. It allows you to make beautiful graphs from the metric data using relatively simple expressions. But one of the graphs that I had in mind, turned out to be more difficult. These are my notes.

I have a metric that counts …


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Half-duplex UART (RS485) on ESP32

Posted on Sun 26 April 2020 in microcontroller

I'm a happy owner of a few ESP32 microcontrollers. These are similar to the Arduino, but have WiFi & Bluetooth built in, which makes them very versatile. These chips come with a lot of peripherals, including three UARTs. These allow offloading the actual bit-banging of the pins to dedicated hardware …


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Raspberry pi 4 as broadband router

Posted on Fri 21 February 2020 in linux

A few years ago, I already considered using a Raspberry Pi as a broadband router. Back then, its first generation wasn't fast enough. This changed with the 4th generation of the Raspberry pi.

The test setup was similar to the setup I use previously:

  • Two beefy laptops on the ends …

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Reading CPU temperature and Fan speeds from the command line in macOs 10.14 Mojave

Posted on Fri 27 September 2019 in macOs

I was looking to read out the current temperature and fan speed of my MacBook Pro running macOS 10.14 Mojave. I prefered build-in tools over shady apps. After some searching, I found the powermetrics tool (which needs sudo privileges). By default, it outputs lots of details every 5 seconds …


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