Manual

This command will turn the motor off by setting the Awaiting Command error bit. The jrk will not restart the motor

until it receives a Set Target command. The jrk can be configured to either brake or coast while the motor is off

(Section 3.e).

Set Target High Resolution

Compact protocol, binary: 110LLLLL, 0HHHHHHH

Compact protocol, hex: 0xC0 + target low 5 bits, target high 7 bits

Pololu protocol, binary: 10101010, device number, 010LLLLL, 0HHHHHHH

Pololu protocol, hex: 0xAA, device number, 0x40 + target low 5 bits, target high 7 bits

(where target is the 12-bit number HHHHHHHLLLLL)

This command clears the Awaiting Command error bit and (if Input Mode is Serial) lets you set the 12-bit target to

any of its allowed values (0–4095). The meaning of the target depends on what Feedback Mode the jrk is in (Section

3.c). The lower 5 bits of the command byte represent the lower 5 bits of the target, while the lower 7 bits of the data

byte represent the upper 7 bits of the target.

For example, if you want to set the target to 3229 (110010011101 in binary), you could send the following byte

sequence:

in binary: 11011101, 01100100

in hex: 0xDD, 0x64

in decimal: 221, 100

Here is some example C code that will generate the correct serial bytes, given an integer “target” that holds the desired

target (0–4095) and an array called serialBytes:

serialBytes[0] = 0xC0 + (target & 0x1F); // Command byte holds the lower 5 bits of target.

serialBytes[1] = (target >> 5) & 0x7F; // Data byte holds the upper 7 bits of target.

Many motor control applications do not need 12 bits of target resolution. If you want a simpler and lower-resolution

set of commands for setting the target, you can use the Set Target Low Resolution commands. Alternatively, you

could use the Set Target High Resolution command with the lower 5 bits of the target always zero: sending a 0xC0

byte followed by a data byte (0–127) will result in setting the target to a value of 32 multiplied by the data byte.

Set Target Low Resolution Forward

Compact protocol: 0xE1, magnitude

Pololu protocol: 0xAA, device number, 0x61, magnitude

This command clears the Awaiting Command error bit and (if Input Mode is Serial) sets the target to a value of 2048

or greater which is determined by the magnitude (0–127).

If the Feedback Mode is Analog or Tachometer, then the formula is

Target = 2048 + 16×magnitude.

If the Feedback Mode is None (speed control mode), then the formula is

Target = 2048 + (600/127)×magnitude.

This means that a magnitude of 127 will set the duty cycle target to full-speed forward (+600), while a magnitude of

zero will make the motor stop.

4. Using the Serial Interface Page 31 of 44