Parallax Feedback 360° High-Speed Servo

The Parallax Feedback 360° provides the functionality of a light-duty standard servo, a continuous rotation servo, a high-speed servo, and encoder feedback in one convenient package. Like typical continuous rotation servos, the speed of the Feedback 360° is controlled by a standard 50 Hz RC servo signal, and the speed response is nicely linear across the control signal range of 1280 µs to 1720 µs. The rest point is at 1500 µs, with a 20 µs deadband on either side. Pulse widths above the rest point result in counterclockwise rotation, with speed increasing as the pulse width increases; pulse widths below the rest point result in clockwise rotation, with speed increasing as the pulse width decreases.

What sets this servo apart from typical other similar servos is a return signal line from an internal Hall effect sensor system that provides digital angular position feedback. Using this feedback signal, your application can make the servo to turn to and hold any angle, much like a standard servo but with an unlimited range of motion. Or, you can rotate the servo continuously at a controlled, verifiable speed as a robot drive motor. The feedback signal is a 3.3 V PWM with a fixed period of approximately 1.1 ms and a duty cycle that corresponds to the rotational position of the servo. More information about the feedback signal, including a low-level programming walkthrough with snippets of example C code, can be found in the Parallax Feedback 360° High-Speed Servo Datasheet (1MB pdf).

The recommended operating voltage range for this servo is 5.8 V to 8.4 V. At 6 V, it has a maximum rotation speed of 140 RPM (no-load), and it has a peak stall torque of 35 oz-in (2.5 kg-cm).

This robotics servo is compatible with Pololu's servo wheels for standard servos (25T, 5.8 mm spline) and Mounting Bracket for Standard-Size Servos, and it works with the control signals generated by Pololu's servo controllers, but please note that you would need a separate microcontroller to read and respond to the feedback signal if you want to use that feature. It has a 9.8" (250 mm) lead terminated with a JR-style 3-pin servo connector, which is used to provide the servo with power, ground, and its control signal. The feedback signal is provided through a separate single wire that is terminated in a 0.1" female connector.

This product is Parallax product ID 900-00360.

Continuous rotation servo comparison

54	71	43	46	41	41.3 × 20.7 × 40.2	CCW?CW
140	35	–	–	41	40.0 × 20.0 × 37.2	CW?CCW
130	21	100	18	9	22.5 × 12.1 × 23.4	CW?CCW