Assembling the Motor Control Electronics

   I'm finally up to the point of building the electronics I'll use for motor control. Basically that means assembling all the ESCs used to drive the 3-phase brushless DC motors. I decided to use hobby airplane ESCs since they're the smallest, lightest, and typically cheapest. Unfortunately, airplane motors are designed to only turn in one direction, so I need to create a system that allows me to switch direction. I decided to use a bunch of MOSFETs to create an H-bridge for each motor. The bridge sits in between the ESC and the motor and can switch two of the three motor leads, reversing direction.



   The red things with all the wires are the ESCs, each of which needs three inputs: 12VDC for the motor, 5VDC for the ESC, and a pwm signal from the Beaglebone. That means a lot of wiring. We can chop off most of the wire shown here since we're going to fit the system inside a very small vessel. I also desoldered the 12V->5V voltage regulator I made earlier and put it on this board. It seemed unnecessary to have two separate boards.



   And here it is all assembled. Well, mostly assembled. I've soldered down all the ESCs,  but they're not connected to the H-bridges yet and the H-bridges aren't connected to output terminals. Also, I have to attach the powerline ethernet card that will connect to the tether. The powerline modem uses 3.3VDC so I need to see if it would be easier to power it from the 3.3V line on the Beaglebone or with a 5V->3.3V converter. I think I have one of those lying around somewhere.

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