Arduino Vibration Logger

Arduino Vibration Logger
Recently I have had to monitor the operation of a system of pumps over a period of a few days. Monitoring in person would be a waste of time and would be a pain to do at night. The operation state of the pumps can be determined by the vibration of the system. When the ...

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, ...

Changing a “dumb” Rinnai water heater to a smart one 31

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 13

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? 42

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 22

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 22

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 32

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 ...

MLT-BT05 BLE module – a clone of a clone?? 145

MLT-BT05 BLE module - a clone of a clone??
Previously I covered the HM-10 Bluetooth Low Energy (BLE) module and its clone, the CC41-A.  Those are two popular modules that allow simple BLE communication through a serial interface and are handy with Arduinos and other hobby micro controllers. Make sure you read that article first as it provides important background for this curious update. ...