Saturday, February 20, 2010

Evolution - superficial and speciation

Time Machine discusses evolution and dichotomy. Speciation is not such a common occurence unless there are heavy evolutionary drivers. I just read Michael Crichton's Prey, all his books carry the same cautionary finger about new technology. Crichton has inspired more research than caution by a lot of his work. Ultimately it is human hubris to blame.

I have lately been excited by the possibilities of distributed processing and mesh networking as discussed in Prey. I can't operate at the nano scale yet, but we can have half-hour endurance swarms with decent processing. The Xbee is great for mesh networking as I have found, currently each node needs to be individually configured, but that can be done over air soon enough. The current version of the quadcopter autopilot can read euler angles from the IMU, read GPS locations at 1Hz and send I2C commands to an Arduino to control motor speeds. What needs to be completed is the control/feedback loop to tie all this together. The hardware also needs to be cleaned up and a power supply segment built, all the bits take so many different voltages - IMU(9V), Arduino+Gumstix(5V), Xbee(3.3V).

The last 2 nights have been spent setting up Xbees correctly. Apparently the fidelity is best in point-to-point mode, where a single router/end-point sends to another - this is achieved by setting the SH/SL and DH/DL registers. The Xbee has a lot of config options, the other neat thing in X-CTU is the inbuilt signal quality testing app. Running cat /dev/ttyS0 on the gumstix lets me create a software loopback and test the signal quality while moving the transmitter around.

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