It was a long and bumpy way from taking pressure transducer hardware in my hands to having stable digitized values. Most of the time I spent learning instrumentation circuitry from app notes and books, just to make sure the solution meets assumed precision despite budgetary approach. Finally constant current bridge driver, precision operational amplifier and sensitive analog-to-digital converter did a job. Continue reading
When laying down PCB track manually usually some other tracks are obstacle and need to be moved away. In KiCad it is manual work, in advanced tools they are pushed making room automatically while another track is approaching. FreeRouter can do this for KiCad but its UI is far from perfection. KiCad will do it natively soon, as shown on this video. Continue reading
One of methods for automatic water level metering is to put a waterproof pressure sensor under the surface at well-known absolute depth and measure hydrostatic pressure that translates into the level of water over the pressure sensor. There is a plenty of such “level transmitters” on the market with prices ranging from $250 from Chinese market to $400 for digital transmission devices on local market. Add to it lengthy capillary signal cable and the price doubles. I have designed and constructed such device for less than $100. Continue reading
Since the spring of 2013 I am working on most complex hardware & software solution I have ever designed and built myself. The undertaking is challenging as I am dealing with complete life-cycle of solution from electronic, mechanic and software engineering perspectives. The solution has to offer data transmission over different protocols in secure manner, has to be self-powered with solar panel and survive outdoor conditions of hot summer and harsh winter being placed on the ground and under the water. And what is even more challenging I am doing it mostly alone. Continue reading
KiCad has some built-in auto routing capabilities for laying out PCB wires. More advanced version, online auto-router from www.freerouting.net, can cooperate with KiCad and gives better results. FreeRouter however does not work in offline even after copying Java Web Start resources to local system; auto-router still checks internet access on startup. Irritated I hacked binaries and got rid of online check. Now you can make your auto-router working anytime. Continue reading
Plan of return to Jo’burg projected a vision of visiting wild life park. Pilanesberg appeared to be better choice comparing to Kruger Park I considered first, as the former is in one-day-visit roundtrip distance. Budget of two free days was simply managed: day one – visit Pilanesberg not being eaten, day two – visit a friend living in Pretoria and get braai eaten.
How to compile FreeRTOS real-time operating system on 8-bit AVR microcontroller Atmega8? It is not supported out of the box as well as google hardly helps with that issue. I did some experiments and understood why people are not doing this. Continue reading
Vegas. Mecca for crowd of Americans looking for something extraordinary. To me a curiosity worth experiencing and catch in a bunch of pictures with a bit of notes on top. Find my first impressions on April 2013 visit to the US capitol of kitsch. Continue reading
Urban skater wearing glasses is in trouble picking up right headphones. The problem is multifold. Let start with head movements that are really rapid, far more aggressive then runner or cyclist does. Wearing glasses means there are extra obstacles near ears interfering with some headphone types. Next, skating streets requires high situational awareness; headphones have to pass through ambient sounds. Also riding inline I can accelerate up to cyclist speed when wind blow cutting through headphones makes extra noise. Finally the sound itself, crisp clear and rich in bass, is what I need. Continue reading
It was nice move to have Beirut on early March work schedule, when the winter was still keeping Europe in tight grasp. For most people Lebanon means danger: neighbor Syria continues crackdown on uprising or the other neighbor Israel that has overran Lebanon couple times in last three decades. For me the chance to feel a place connecting west and middle east cultures, to taste famous cuisine and witness scars of modern military conflicts. Continue reading
