As i was testing my battery with my helicopter, this is not going to be the battery i use, It is a 7.2v 2A Nimh battery pack that i had acquired, as i was putting stuff together and testing my servos, I also wanted to do a quick battery test, so i rigged everything up like it supposed to, i also created a quick motor test on mbed.org to program the uC and get the servos at 90o and get the blades leveled so i can do the motor test.
servos work great with this setup, that test is done, went with out a problem. next was the motor test, so i removed the blades to protect me and the wires. Then i hooked everything up. checked the motor, and the battery connection, perfect no problems. next i hook up the uC control lines and ground (I learned 🙂 ). or so what i thought was ground. so i power every thing up. nothing goes, check the battery and all the power, looks good. next i remove the control lines.(or so i thought) checked the voltage from the pwm line, about 3v, looks good. so i use the control line that was being used for the main rotor and hooked it up to 5v nothing happened, so i thought ok maybe my gate voltage wants high enough, (last time it was 5v source and 5v gate and it worked) so i get the brilliant idea of trying to hook it up to one of the power line, a full 7.2v (8.5v fully charged) thinking that should be enough power to get it going ………………guess what ……………
I hooked up what i thought was the main rotor gate, but instead i hooked up the battery right to grnd, shorted it our and had a few sparks……good thing it was a straight short though on the battery and not some critical component…….
the damage …………………..
don’t worry its just a 3rd degree burn lol no real pain involved and yes that is after i had washed it and cleaned it…………Even the cheap PCB that it is soldered on held up very well, it burnt a little and some of the epoxy vaporized, but its still all there and will hold a current(I tested it with a motor test).
reminder to self double check all power connections , including ground and all data lines………..
I think that sums it all up 🙂 enjoy my fail