This is the story of how daisy-chained a bunch of electronic shelf labels into a panel to decorate my office (a thread) I had bought two dozen of these little displays after coming across @atc1441’s work. I played around with them for a little while and even made a small contribution to the project ​​github.com/atc1441/ATC_TL…

When I started working on my soil moisture sensor, I had little idea about how harsh an environment the soil really is. In this 🧵, cool failure modes & solutions when sticking electronics in the ground: If left completely unprotected, water will slowly creep in when we stick a PCB in soil. In my tests, this takes from a few weeks to a couple of months.

I recently joined the very exclusive club of cat printer owners. I spent some time reverse engineering its Bluetooth Low Energy protocol and wrote a little open source client for it. 🧵👇 This is a tiny, battery-powered thermal printer that sells on AliExpress for around $20. It’s meant to be controlled by its proprietary & closed source iOS/Android app. The app connects to the printer via Bluetooth Low Energy (BLE).

I spent some time this weekend looking into another cheap smart watch. This ones sells for $17 on AliExpress There is no product name in the box & the marketing pics are a little misleading. The display is not even round, but just a square of 240x240 pixels. It's just glued to the middle of the dial

Here’s the fascinating way these capacitive soil moisture sensors work. If we stick them in the ground, we can monitor the moisture level in the soil via its analog output. It spits out a voltage that is proportional to how wet the soil is.