DEV.BG tech talk

I will be doing a tech talk on topic “Hardware and firmware considerations when designing low power battery operated wireless edge nodes for Internet of Things applications” at an event organized by DEV.BG. Join me on April 18th, starting 19:15 @ IT Step Academy. If you are in Sofia, you are invited to join. Page…

Where are the IT jobs in Sofia located?

I had a chat with a colleague the other day, discussing his property purchasing plans. He shared that the proximity to workplace is important for him. Planning in the long term, he asked me what districts of Sofia would be a good fit in my opinion, and I could only guess. Driven by curiosity, I…

proSmart

I have been busy starting up an exciting new project the last few months, a joint effort with a team of highly enthusiastic, hands-on, broadly skilled contributors with the goal to design and develop IoT home/industrial automation solutions. Together, we established a company named proSmart with the following principles in mind: Provide end-to-end services Complete service…

Auto DST adjustment

We are close to that time of the year when Daylight Saving Time (DST) starts.  It is intended to save on energy use, however, studies have found this to be questionable, even contrary – energy use increases in some cases. The change itself causes a number of inconveniences. For me DST start/end means adjusting a number of clocks around…

Local hostname for connected devices

Now that we have connected our project to the local network, we are immediately faced with another challenge: how can we reach it? Using WPS/SmartConfig means we force the unit into DHCP settings mode, IP address is auto assigned by the router in that case. You may not have access to the router’s settings to force static IP…

The initial setup problem

The typical end-user of your IoT products wants them up and running fast, with minimum hassle once they bring them home. They don’t want to be presented with initial configuration mechanisms/options they don’t understand, and their enthusiasm quickly diminishes if you make them struggle to get the product going. Page views: 2992

My own cloud based version control tool

There is no second opinion about the importance of version control, it is a must-have for any software project. The option for reversibility, concurrency and history of code edits is what makes it so crucial. I’ve been using mostly GitHub for the purpose, it seems the version control tool of choice for many these days. I…

Some thoughts on security in terms of IoT

Connected devices and sensors are the fastest growing sources of data. Billions of records are being generated daily around the globe and data transported across networks to be consumed where needed. Security of data in transit or at still in that context (especially when it comes to sensitive personal data) is quite important. Back in 2011…

Physical vs Virtual

The Raspberry Pi, a $35 credit card sized computer, is a popular choice for home automation projects. I am running few of those at home myself. But what is the true cost of these, is the advertised cost of $35 really all you spend?  Before you know it, you throw in  more bucks for a decent power…

Google video tech-talk hangout anyone?

I’ve been meaning to hold a video Google hangout session on IoT topics for some time now, how about giving it a try? I imagine it as informal 1 hr tech-talk with the following structure 35 min presentation of a certain topic by a community presenter 15 min comments, Q/A on the presented topic 10…

I am a @quantifiedself

I accidentally landed on a site called ‘quantified self’ last month and immediately realized I am doing lots of lifelogging myself. I track my commutes, log my weight, my body temperature when sick, my hot water usage habits, visitors to my home, coffee drinking. Power usage tracking  and habitat monitoring provide useful insights on my…

Thoughts on AVR ADC accuracy

I was thinking about the accuracy of the battery measurements the other day, are these accurate or not? I measured the battery using Fluke 27 multimeter and compared that to the readout using the internal bangap method and found a small difference. Googling on the subject revealed that the supposedly 1.1V internal bandgap reference can actually vary.…

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…

DHT22 accuracy test part 2/2

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 data…Got Data 25.50C 75.20% Integer-only reading: Temperature 25.5 C, Humidity 75.2 % RH Requesting data…Got…

DHT22 accuracy test part 1

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 causing the issues. He sent me a 3D printed Stevenson screen to try, but I…