Clapping to control RF power sockets

I did a fun experiment this evening, clap controlling RF power sockets using Funky v2‘s radio module and a sound sensor breakout module. The latter is pretty cheap one, respectively low quality and performance:   It has couple outputs: analog and digital one. The digital output goes HIGH upon audio signal from the microphone reaching…

Door sensor

I have recently purchased a magnetic contact switch to toy with. These are really cheap sensors that are used to detect door (or window) opening/closing events. The principle of work is simple, the sensor consists of two parts: one is a magnet and the other is a reed switch with a smaller magnet attached. Bringing…

Every μA counts

When you run a project on battery, you are always thinking on how to conserve power so that you run longer. In the case of wireless remote nodes you do that by sleeping a lot and only waking up briefly to do some useful work (I know people that do the same). That requires a set…

Non-contact AC detection

Alex from insideGadgets had an interesting project last year on non-contact AC detection and I wanted to try it out and learn how it works. He hooked one leg of a 1M ohm resistor to GND and a wire to the other that goes to an Analog input. The wire acts as an antenna and…

Trying out bistable/latching relay

I purchased a Ciseco bistable/latching relay few months ago for the sake of trying it out. I don’t have a particular project that requires one, just wanted to toy with it. If you haven’t heard of this type of relays, they are pretty cool because they only need a brief pulse to set and another…

Raw infrared <> serial

When interfacing my gadgets to the physical world, I often need to deal with IR of all sorts: air conditioners, TV, audio equipment, media center and so forth. These are all of different brand, so naturally the IR protocol that the remote controls have is different. Some of the more popular ones can be decoded…

Flood alarm

My father had a leaking pipe accident last year, and it happened while he was away from his place for a week. The water was flowing for few days before he returned and that caused damage for thousands of Euro, not to speak about the inconvenience. To minimize the damage of such possible future events,…

Funky v2 revision 2

I have made a small improvement to the Funky v2 by adding a reset button to the PCB. The lack of reset button in the previous releases caused some inconvenience when the sketch being run disables USB connectivity (for power-saving purposes), the Funky would become unrecognized by the host system. I was working around this…

Wireless body temperature monitor/logger

I have been experimenting the last couple days with a wearable electronics project – a wireless body temperature monitor/logger. The idea is to remotely monitor kids body temperature, if they are sick, and put up a status display with alarm function in our bedroom. The remote monitor will be another Funky with RGB LED for…

OLED analog clock

I have updated my OLED status display project with an option for analog clock: I also experimented with drawing bitmaps, a thermometer is drawn to the right of the clock face that changes its reading according to the solar water tank temperature. Time and temperature are captured from the wireless packets of telemetry floating around…

Reducing RFM12B transmission power

@Dimitrios noted something very important in the comments to an earlier my post on low-power sketch: One of the things I noticed when I started playing with the RFM12B module was that the receiver front end was mostly overloaded by the strong transmitter output (1~ 5dBm). This has a negative effect in the quality of…

Optimizing DS18B20 code for low power applications

I have been uneasy with the conversion time that the DS18B20 temperature sensors have,  it is 750 ms when using the 12-bit resolution: The 12-bit resolution is the default power-on, so when powering the sensor from a digital pin, you always end up in 12-bit resolution (this is the typical approach when a sensor is…