Should you throw away your CC41 HM-10 clones now that Android 8 is here? 17

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 (or newer) phone. Why is that happening and what can you do about it? tl;dr, the issue is due to a bug in the ...

40 cent DIY pressure sensor based on a capacitive principle 5

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 7

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 9

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?? 80

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. ...

HM-10 or CC41-A module? Automatic Arduino BLE module identification 53

HM-10 or CC41-A module? Automatic Arduino BLE module identification
Lately I am working a lot with Arduino, which is a new field for me, hence fewer posts. Arduino is a very popular entry level embedded electronics platform. My latest Arduino project features Bluetooth Low Energy (BLE) communication. Arduino boards have no built-in BLE capabilities so I was looking to add a BLE module to ...

Capturing and reversing wireless keyboard signal

Capturing and reversing wireless keyboard signal
Recently I have made a presentation at the “Software Defined Radio Israel” meetup about my work capturing and reversing wireless keyboard signals. I focused on a “Rapoo E2700 keyboard and track-pad” but we also discussed the broader challenge of such capturing for SDR enthusiasts. The project involved capturing 2.4Ghz wireless signal with an RTL-SDR dongle ...

Arduino sound level meter and spectrum analyzer 192

Arduino sound level meter and spectrum analyzer
Recently I have been doing some projects with the Arduino electronics platform. One of the projects involved benchmarking certain motors and required me to measure noise levels. I  will cover that project in more detail in one of the future articles, but now I would like to write about the process and best practices of ...

Why use – Fosphor, a GNU Radio real-time spectrum analyzer?

Why use - Fosphor, a GNU Radio real-time spectrum analyzer?
Lately I have been experimenting with Software Defined Radio, SDR, which is a software-based radio signal processing system. I find this field intriguing. I can capture all kinds of signals in the air and get a better understanding of how technologies and gadgets around me operate. During my exploration of SDR I discovered one tool ...