Motor Test

So, last night I did a quick motor test using my laptop to send servo data over an FTDI cable to a Boarduino. The Boarduino is using the Servo library to address the ESC.

Video after the jump.


Video on YouTube


The motor in the video is the BL2204/14 I will be using for lift, and produces a surprising amount of air. Not being familiar with brushless DC (BLDC) motors, I was not expecting that much power out of such a small motor. When I tested the Hacker, which will be used for thrust, it nearly pulled itself out of my hand at 70% throttle.

I noticed two issues with this test. The first is that the ESC appears to limit the active throttle range to between 45 and 135 degrees of servo position command. It appears to run the full range of motor control within this range, so it should be fine. The other issue I noticed is that the Hacker motor tends to stutter when starting. However, it appears that this is a common thing to see out of these motors if the wiring is sketchy between the ESC and the motor, so I will worry about that once I get everything wired up properly.

After some discussion with folk in #sparkfun on Freenode, the ESC itself appears to have a simple programming interface, so I may attempt to talk with that to get direct access to the throttle setting, rather than trying to emulate a receiver to control the ESC as a servo--two layers of abstraction I really do not need. This realisation came from analysis of the Castle Link programming cable, which appears to be a standard FTDI USB-TTL serial adapter. At the very least, this will allow me to use fast, low-level setup programming, rather than trying to emulate stick programming with the Servo library--ick.