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…
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,…
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…
Installing emoncms’s “events” module
I use emoncms to log telemetry readings from various sources (wireless sensor nodes, software bots etc), the so logged data helps my IoT connected gadgets make decisions, based on pre-defined rules. For example, my heat pump monitors outside weather conditions (temperature,…
Pong clock on Raspberry Pi + 1.8″ TFT
There was a blog post on http://raspberrypi.org couple days ago about a pong clock, these seem to be quite popular these days. A simple search on hack-a-day shows dozens of such projects, so the idea is not new. Still fun…
Micro IoT gateway RFM12B shield update
I have created a new version of the micro Internet of Things gateway RFM12b shield since the first revision had some drawbacks. The new version has a port that allows an OLED display to be plugged on top, this creating…
Putting Raspberry Pi’s hardware watchdog to work
As I continue my quest for reliability of my Raspberry Pi computer, I stumbled upon something interesting that I didn’t know existed – hardware watchdog for Raspberry Pi. For those hearing this term for the first time, a watchdog is…
Moving the root file system of Raspberry Pi to external USB drive
I have had enough of damaged Raspberry Pi SD cards due to frequent power outages here. This week I have ended up with damaged SD card number three and had to take measures to prevent this from happening again and…
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,…
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…
Tweeting coffee machine using Raspbery Pi
Here is a small project for social network connected home appliance, done for the sake of fun, but provides a good learning experience. I will be connecting my coffee machine to Twitter since I am one of the 6 people…
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…
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…
Raspberry Pi email/SMS doorbell notifier + picture of the person ringing it
I have been receiving requests to build a SMS doorbell from all around the world ever since my SMS doorbel project got featured on hackaday, damnGeeky, hackedgadgets and few other places . My approach is relatively difficult to follow, so I decided to…
High AC mains voltage
My house is second to the power supply transformer and I have been observing some pretty high AC voltage levels. I previously had a really cheap multimeter and thought that the readings are off because of its bad quality. Never…