User Manual

need to send. The second byte specifies the lowest channel number in the block. The subsequent

bytes contain the target values for each of the channels, in order by channel number, in the same

format as the Set Target command above. For example, to set channel 3 to 0 (off) and channel 4 to

6000 (neutral), you would send the following bytes:

0x9F, 0x02, 0x03, 0x00, 0x00, 0x70, 0x2E

The Set Multiple Targets command allows high-speed updates to your Maestro, which is especially

useful when controlling a large number of servos in a chained configuration. For example, using the

Pololu protocol at 115.2 kbps, sending the Set Multiple Targets command lets you set the targets of 24

servos in 4.6 ms, while sending 24 individual Set Target commands would take 12.5 ms.

Set Speed

Compact protocol: 0x87, channel number, speed low bits, speed high bits

Pololu protocol: 0xAA, device number, 0x07, channel number, speed low bits, speed high bits

This command limits the speed at which a servo channel’s output value changes. The speed limit

is given in units of (0.25 μs)/(10 ms), except in special cases (see Section 4.b). For example, the

command 0x87, 0x05, 0x0C, 0x01 sets the speed of servo channel 5 to a value of 140, which

corresponds to a speed of 3.5 μs/ms. What this means is that if you send a Set Target command

to adjust the target from, say, 1000 μs to 1350 μs, it will take 100 ms to make that adjustment. A

speed of 0 makes the speed unlimited. Setting the target of a channel that has a speed of 0 and an

acceleration 0 will immediately affect the channel’s position. Note that the actual speed at which your

servo moves is also limited by the design of the servo itself, the supply voltage, and mechanical loads;

this parameter will not help your servo go faster than what it is physically capable of.

At the minimum speed setting of 1, the servo output takes 40 seconds to move from 1 to 2 ms.

The speed setting has no effect on channels configured as inputs or digital outputs.

Set Acceleration

Compact protocol: 0x89, channel number, acceleration low bits, acceleration high bits

Pololu protocol: 0xAA, device number, 0x09, channel number, acceleration low bits, acceleration

high bits

This command limits the acceleration of a servo channel’s output. The acceleration limit is a value

from 0 to 255 in units of (0.25 μs)/(10 ms)/(80 ms), except in special cases (see Section 4.b). A value

of 0 corresponds to no acceleration limit. An acceleration limit causes the speed of a servo to slowly

ramp up until it reaches the maximum speed, then to ramp down again as position approaches target,

resulting in a relatively smooth motion from one point to another. With acceleration and speed limits,

only a few target settings are required to make natural-looking motions that would otherwise be quite

5. Serial Interface Page 56 of 102