Easy wireless mesh network with ESP32s and Arduino

Introduction I have a Home Assistant-based Smart Home in my apartment. Many of my electronic devices are connected to HA and I can monitor and manage them centrally. The main communication method for all the devices is Wi-Fi with Zigbee being a second option. Some time ago I wanted to monitor several processes outside of … Read more

Convention for compile time configuration of PlatformIO projects

Separation between code and data (specifically configuration data) is a critical concept in any development environment. Having worked a lot with the nodejs stack I found the way configuration is handled in embedded Arduino/PlatformIO projects surprisingly messy. I decided to come up with a convention to simplify this and I will describe it below. tl;dr, … Read more

Changing a “dumb” Rinnai water heater to a smart one

This article covers a home automation project, in which I extended a control panel of a Rinnai gas water heater with an ESP32. The ESP32 then functions as an interface between the control panel and Home Assistant, a home automation software. tl;dr, the ESP32 sits as a MitM (proxy) on a few data lines inside … Read more

Repurposing unused steering wheel buttons as generic macros for an Android head unit

This article covers an automotive project, in which I connect unused buttons on my car’s steering wheel to a micro-controller, which in turn emulates a keyboard and mouse device to the car’s infotainment system via USB. tl;dr, the buttons form a resistor ladder and I use an STM32 black pill board to read the state … Read more

Should you throw away your CC41 HM-10 clones now that Android 8 is here?

With the release of Android 8.0 (“Oreo”), I as well as others have noticed that they cannot find some HM-10 clone BLE modules when scanning for them with an Android 8.0 phone. Why is that happening and what can you do about it? tl;dr, the issue is due to a bug in the firmware of … Read more

40 cent DIY pressure sensor based on a capacitive principle

Lately I am spending a lot of time working on Fochica. Fochica is a system that alerts parents if they unknowingly leave a child in a car. The Fochica device is Arduino-based, installed in a vehicle and communicates with the parents’ smartphones via Bluetooth. Fochica is a finalist in the Hackaday Prize 2017 competition and … Read more

Efficient DC 12V to 5V conversion for low-power electronics, evaluation of six modules

I am currently working on a vehicle-installed Arduino project. The device is designed to be powered constantly and I decided to use the car battery as the constant power source. I am designing the device for low power consumption, consuming 50mA or less, ’cause who wants to get stuck with a flat battery, right? Car … Read more