<spd> portion of Servo Move Command Problem

[sjblair4]

The portion of the # P S … # P S T gets all servos specified in a multi servo move at the same time. It’s like the S argument has no effect on servo motion speed. No matter what I specify for multiple S arguments, all servos travel at the same speed. Any suggestions?

[robotdude]

@sjblair4

The portion of the # P S … # P S T gets all servos specified in a multi servo move at the same time. It’s like the S argument has no effect on servo motion speed. No matter what I specify for multiple S arguments, all servos travel at the same speed. Any suggestions?

From the manual…

Any move that involves more than one servo and uses either the S or T modifier is considered a Group Move, and all servos will start and stop moving at the same time. If you require moving several servos at different speeds, you must issue the commands separately.

What were you expecting to happen?

[sjblair4]

I was expecting a one line command with different parameters for multiple servo channels to use each servos parameter. Otherwise why is it an option to have multiple arguments? Which argument wins, the last or the first?

[robotdude]

@sjblair4

I was expecting a one line command with different parameters for multiple servo channels to use each servos parameter. Otherwise why is it an option to have multiple arguments? Which argument wins, the last or the first?

Please show me some examples of the commands you’re sending and the results you are seeing. Not sure if you are having a problem with hardware or the use of the commands.

From the manual…

Servo Move Example: "#5 P1600 S750 "

The example will move the servo on channel 5 to position 1600. It will move from its current position at a rate of 750uS per second until it reaches its commanded destination. For a better understanding of the speed argument, consider that 1000uS of travel will result in around 90° of rotation. A speed value of 100uS per second means the servo will take 10 seconds to move 90°. Alternately, a speed value of 2000uS per second equates to 500mS (half a second) to move 90°.

[robotdude]

@sjblair4

I was expecting a one line command with different parameters for multiple servo channels to use each servos parameter. Otherwise why is it an option to have multiple arguments? Which argument wins, the last or the first?

There is a good explanation of the rules that are applied to the S and T arguments in the manual. But if you require different speed of movements, you simply send the commands separately, I.e. with a CR behind each one.