Pololu Micro Serial Servo Controller - 180 degrees

I have Pololu Micro Serial Servo Controller https://www.pololu.com/catalog/product/207

And my question is how to control it in 180 degree mode!
Im sending sequence of bytes as [255, servonumber(8 through 15 - upper servo numbers) and position 0 to 255] and servos moves about 150-160 degrees only. How to control it in really 180 degree? It’s desirable for me to use mini ssc mode as i am short of traffic :slight_smile:


I split your post from the other one because it had nothing to do with the Pololu Maestro servo controllers.

The answer is probably that your servo cannot do 180 degrees, but can you tell us what servo you have and whether you have verified any other way that it can move as far as you want it to? Also, does it move throughout the entire range of MiniSSC 180-degree commands, or does it hit stops on one or both ends before the commands reach their limits?



I also just want to point out that 255 is used as a special sync byte in the Mini SSCII protocol, so the servo position byte can only have values from 0 to 254.

- Ben

Yes, it stops before limits.
I have many different servos ordered from ebay, each servo varies a little, but no one reaches it’s limits :frowning:
Also when i done servo controller by myself in pic16f84, i used pulsout command, and servo does move to the limits, something about 190 degrees.

I think you are using the words “limit” and “stop” in oppositely from me. But anyway, if you have experience doing the pulse control yourself, can you just tell us the actual timing of the pulses that you want to send? In Mini SSC mode, you can send pulses from 500us to 2500us. To do longer pulses, you would need to use the Pololu protocol, and the controller does not do anything shorter than 500us no matter what (you could get a Micro Maestro if you need that.)


Sorry! I was wrong about the 500us limit. With Pololu mode, you can access the full range of 250us to 2750us.


i need a standard servo timings, in my pic-based controller it’s 500us to 2500us. (50 to 250 in 10us increments)
“Stop” it’s when it simply stops no matter why, and “limit” it’s like motor trying to move on, but there is mechanical limitations, and servo makes noises, drawing high current, and actually destroying himself :unamused: i think so…

Seems like pololu mini mode uses much narrowed range :frowning: i will try to measure it’s range soon.