Integrating 433Mhz smoke detectors with Home Assistant

Integrating 433Mhz smoke detectors with Home Assistant
Smoke detectors are simple and effective means for saving lives and reducing damage to property in case of a fire. You should use smoke detectors in your house even if your local regulations don’t require you to do so. All smoke detectors make a loud beeping alarm sound if smoke is detected but some models ...

Convention for compile time configuration of PlatformIO projects

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, ...

Making a proper adapter board for the “smart” WiFi Rinnai

Making a proper adapter board for the
This is a quick follow-up post to my previous article about converting a Rinnai heater device to a smart device and controlling it with WiFi. Previously, when making the board that connects between the ESP32 and the traces of the Rinnai control panel, I did something that is not per-spec. I was using the ESP32 ...

Changing a “dumb” Rinnai water heater to a smart one 6

Changing a
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 ...

Repurposing unused steering wheel buttons as generic macros for an Android head unit 7

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 ...

Should you throw away your CC41 HM-10 clones now that Android 8 is here? 40

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 ...

40 cent DIY pressure sensor based on a capacitive principle 13

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 ...

Fochica™ – Forgotten Child in Car Alert

Fochica™ – Forgotten Child in Car Alert
Over the last 12 months I have been working on an interesting project with an important mission: to prevent forgetting children in vehicles. Kids who are left alone in cars are likely to suffer a heat stroke, often with grave consequences. Naturally, this is a bigger concern in hot countries, such as Israel, where I ...

Fixing a bad STATE pin on an MLT-BT05 BLE module 17

Fixing a bad STATE pin on an MLT-BT05 BLE module
This is a follow up article to the detailed review of the MLT-BT05 BLE module. In that previous post I mentioned that I got some MLT-BT05 modules with their STATE pin floating. No working STATE pin was an issue for me and I decided to investigate the cause. Update: same issue was observed with Bolutek ...

Efficient DC 12V to 5V conversion for low-power electronics, evaluation of six modules 29

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 ...