quadcopter

schematic and board files are licensed CC-BY-SA-3.0
source code licensed under the GNU Public License v3

an atmega168 generates pwm outputs to three half-h-bridges which each drive one phase of the brushless motor. a voltage divider returns that phase's back emf to the atmega when that phase is not being driven, which the atmega uses to calculate the commutation time. a shunt resistor and amp is used for current monitoring. an i2c interface talks to the main system. the i2c address is settable from four options by a solder jumper. there are some status LEDs. the mosfets are to220 packages and are each driven by transistors. the board is about 0.9" by 1.7". screw terminals connect to the battery and motor, or you can just solder wires into the holes. drc clearance is 7/7 with 12mil minimum drill size. seeedstudio and goldphoenix will both manufacture this board (though you will need to pay goldphoenix a bit more for the 12mil drill hits).