I still have yet to permanently mount my Arduino and top off the helium cells, but I figure it’s about time to reveal my child (and to some extent Thiago’s) to the world. It still hasn’t flown untethered yet but hopefully it will soon. Without further ado, here is a somewhat flaccid Emu.
All things considered, it does pretty well with only 2 limp balloons holding it. Fully inflated, the helium cells ought to bring Emu to an almost perfect 0-gram weight.
As part of the weight-saving measures on Emu, I took the liberty of cutting open the power connector for the wireless camera. The camera used a chunky coaxial power connector to hook it up to 9 volts that accounts for over half the weight of the module. After cutting the cable, however, and dissecting the plug itself, I realized the manufacturers had used the egregious volume of the plug to hide a voltage regulator inside. (Brian identified a component on it as a transistor, and I looked up VReg designs on wikipedia. Sure enough, a transistor with a resistor array can be used as a voltage regulator)
After a lot of exacto-knifing and a bit of soldering, the VReg circuit was excised and grafted onto the wires of the camera. The one drawback is that the mass of the original plug acted as a heatsink of sorts and the new setup causes the voltage regulator to heat up significantly. It hasn’t melted the scotch tape on it yet. I will switch it to electrical tape soon, and wrap the entire thing in a few turns of bare wire to dissipate heat.
Hopefully nothing further will go wrong this week. I need to get everything completed and running ASAP. In the mean time, two people (one staff, one faculty member) have given me a small measure of praise for my work so far. Both identical statements: “Not bad, for a mechanical…”
Also, my gratitude to Sparkfun for their surprisingly human (read: courteous) customer service department helping me replace a dead Arduino Fio. Appreciate it, guys.