Tuesday, October 2, 2012

New life

After some (long) pause in this blog I decided to resume it. I took several online classes (mainly in AI and machine learning) and it takes a sizable piece of your free time. But nevertheless I did some stuff which I'd like to share here.

I'm into model helicopters now, I'm still a beginner, but I bought several small helis, broken some and repaired some. I disassembled every heli I got, and their design was very interesting for me, so I plan to share my experience here. So far I have cheap Chinese small helis: coaxial 3ch Syma S107g, 4ch S800g, WL Toys quadcopter V929,  fixed pitch single rotor V911, and a bit larger single rotor Double Horse 9116. You gonna need soldering iron to repair some of this stuff

Another project is modification of Ladyada's iNecklace - RGB LED, auto turn off using photosensing. The design is so miniature that it is a big challenge both from physical and programmatic points of view. Still work in progress.

Unfortunately, my EKG efforts stalled. After I moved promising design from solderless breadboard to normal one and then to home-etched PCB it stopped working. Apparently I need to learn more about instrumentation amplifier design. You could put a stock Instrumentation OpAmp there, but then there is no challenge ;-) I still plan to debug the cheapest design possible.

My radio efforts moved to 2.4GHz (it's popular for helicopter RC), so I have several small modules based on various chips: nRF24L01+, it's full Chinese clone Beken BK2421 (the module company even refers you to nRF's site for the datasheet), Amiccom A7105 (popular in Chinese RC models), and CC2500. They all are pretty similar in abilities on paper but have very different settings and their register sets are very large - 50 registers is not unusual. So, trying to make sense out of this zoo.