I am still looking into buying a SSC-32 and I have concerns over the update rate for each individual servos…
Say I have 32 different servos which operate in different ways, but they need to be closely coordinated. Ideally, they would be started and stopped simultaneously.
What is the fastest update rate that one could expect for each individual servo using the SSC-32—>
- Using the group command? How many servos can be given updates simultaneously?
- Using binary commands? Are all servos within a bank given the same update position, or can they be updated separately within 20ms?
thanks,
Stuart
Well, I don’t know anything about the binary (mini-ssc) mode, but I can help you with the rest.
The fastest possible update that a servo can recieve (with the original firmware) is every 20 ms (50 Hz).
It does this by splitting up the servo outputs into four banks.
Each bank is sent every 2.5ms.
Thus, it takes four 2.5ms intervals to get back to the start.
However, there is a 10ms pause before the servo pulses are again sent.
Thus, 2.5ms x 4 + 10ms = 20ms
Try to remember, though, that 20ms is not a noticeable amount of time.
Perhaps you could detect the differences in movement if you stared at them for a long time, but I surely can’t.
Unless you need a ridiculous amount of precision (in which case hobby servos are NOT the way to go) 20 ms updates should do for almost every task.
About the updated positions…
The servos in each bank are sent their individual position instructions.
As far as I understand it, the SSC-32 takes your string of instructions, breaks them up into four seperate instructions, and then sends the piece-meal instructions to their respective servo banks.
