I have had a good share of frustration with damaging Raspberry Pi SD cards due to wearing out/improper shut downs as a result from power failures and was looking for solution to this sort of problems for a while. At first…
I have found my Raspberry Pi running the root file system off a USB flash drive in no good state this morning, the following error showing up on emoncms that was installed locally: Can’t connect to database, please verify credentials/configuration in…
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…
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…
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,…
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…
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,…
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…
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…
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…
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…
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,…
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…
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…
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…
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…
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…
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…
@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…
I sometimes need to quickly check on certain temperature reading and find myself walking to one of my status displays to see, for example, if there will be enough solar hot water for a hot tub. I figured, it would…
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…
I purchased a small serial OLED display few weeks ago, it showed up yesterday at the mail box. Dimensions of the PCB are (WxHxD):30x28x4.8mm (1.2X1.1×0.19″) and the display itself is 22x12mm with 128×64 pixels. Pixels are really bright and viewing…
I have measured the relative humidity as per my set up, and got steady readouts exactly in the 75% area as expected: DHT22 Library Demo Requesting data…Got Data 25.50C 75.20% Integer-only reading: Temperature 25.5 C, Humidity 75.2 % RH Requesting…
I already mentioned, that I have a small RFM12B ‘shield’ that can be used instead of the nRF24L01+ on a WorkerB!. I put one to a test today, all working as expected: This makes it easy to…
I have been boggled for a while about the Relative Humidity data that I gather, I get some higher than expected reading. I blogged about this in this post and @Dimitrios suggested in the comments that my box my be…
I did some range testing earlier today, using a ping-pong pair of sketches uploaded to a WorkerB! and a Dirt Cheap Low Power Wireless Sensor Node: This works by sending an incrementing value (millis’ value) every second, and the…
I have received 5 test PCBs today of the unnamed ‘ATMega32u4+nRF24L01’ board project that I described earlier, I decided to call it a ‘Worker Bee’ or WorkerB! as its task will be to collect and transmit data. The final PCB layout…
@Dimitrios commented the other day on my Funky+DHT22 post that my readings seem to have a lot of 99.9% relative humidity readouts and suggested that it may be due to the black box that I enclosed the project. I do…
There is a relatively new product by Texas Instruments – the SimpleLink CC3000 WiFi module that is quite small and cheap – $12. Looks quite promising, size is about as much as a fingernail: There is a KickStarter project using…
My father asked me to create a standalone power monitor for him, he’d like attach it to some appliance and see its momentary and accumulated over time power consumption. Using OpenEnergyMonitor’s resources that was an easy task to do. I…
My Funky+DS18B20 temperature logging project is still running on that same CR2032 battery ever since my original post back in Oct 31st 2012, that makes it 7 months of run time so far. I have a live chart here: It…
I have finally found some time today to put my keypad project into work, namely I decided to use it for weight logging project here a home. The idea is simple: take measurement using the bathroom scale, then punch in…