Controlling a brushed motor ESC from the Raspberry Pi

Question

I've tried solutions from similar problems, but none of them gave me any usable results. I'm trying to control those http://www.ebay.com/itm/311177661450 electronic speed controls (ESCs) with Raspberry Pi.

I have tried solutions from the question How to control a Traxxas XL-5 ESC directly from the GPIO?.

I've also tried couple of other solutions, but no result. Basically, when I "flip the switch", the ESC makes triple sound and then rotates motor a little bit once a second. I've tried sending a pulse with width 200 and 100 to make this so-called ESC initialization happen, but no change.

I haven't received any documentation, nor couldn't find any online, so I'm kind of not sure where is the problem coming from.

Answer 1

An ESC is controlled in the same fashion as a servo with control pulses. However because of the risk of serious damage (ESCs can control upwards of 30 amps) they often need a special sequence to start.

I suggest you download and install my pigpio library. It will allow you to send servo/ESC control pulses from any gpio available on the expansion header.

After make/make install try

sudo pigpiod # starts a daemon

pigs s 4 1000 # minimum throttle
sleep 1
pigs s 4 2000 # maximum throttle
sleep 1
pigs s 4 1200 # slightly open throttle

Replace 4 with the gpio you have connected to the control wire of your ESC.

Make sure to connect the ESC power supply ground and the Pi ground.

If that doesn't work you'll need to trawl the web for ESC initialisation sequences.