Hi,
I am currently using the Pololu mode on the Pololu circut to control the servos on my robotic system, as I am aware of the documentatin says if we use the pololu mode we can send data from 500 to 5500 to the port to control the servo movement therefore, we have 5000 positions to go with but, I am afraid I couldn’t figure it out that the 5000 positioning is within how many degrees is? for example, is the 5000 positioning designed to be within 180 degree or 360 or …???
I would be so grateful if any one who knows let me know the correct answer,
Thanks
How far your servo will move (as in degrees) as you change the position command depends on the specific make and model of the servo. The simplest way to figure out the relationship is to measure it, like by working out positions separated by 90 or 180 degrees. It’s a fair assumption that the position will change linearly with the command. If you want super-precise calibration, you could pick up one of these servo protractors. Really though, if you need your position control to be that accurate hobby servos probably aren’t going to cut it. Most only have an resolution of ~1.5 degrees anyway.
Hobby servos are controlled by the length (as in time) of control pulses sent to them. Most servo controllers generate pulses between 1 and 2 milliseconds (ms) long, and 1.5ms is usually the ‘center’ positoin. The command you send to your servo controller directly corresponds to the length of the servo position control pulse. Using Pololu mode and the absolute position command (command 4) what you’re specifying is the length of the control pulse in halves of a microsecond (0.0005ms). For example, 500 corresponds to a pulse length of 0.25ms, and 5500 corresponds to a pulse length of 2.75ms. This extra range allows you to push servos (literally) to their mechanical limits.
Hope that clears things up.
-Adam
