Continuous rotation servo v2.0

ManualsBrandsParallax ManualsAutomationServo Motor 268.3 Nmm 50 min -1 140 mA

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Tech Support: (888) 997-8267

Parallax Continuous Rotation Servo (#900-00008)

The Parallax Standard Servo is ideal for robotics and basic movement projects.

Features

Bidirectional continuous rotation

y 0 to 50 RPM, with a linear response to PWM for easy

ramping

y Accepts four mounting screws

y Easy to interface with any Parallax microcontroller or

PWM-capable device

y Very easy to control with PBASIC's or SX/B's PULSOUT

commands

y Manufactured for Parallax exclusively by Futaba

Technical Specifications

Power requirements: 4 to 6 VDC

y Maximum current draw: 140 +/- 50 mA at 6 VCDC when operating in no load conditions

15 mA when in static state

y Communication: pulse-width modulation; TTL/CMOS 3.3 to 5V

y Dimensions: approx 2.2 x 0.8 x 1.6 in (5.58x 1.9 x 40.6 cm) excluding servo horn

y Operating temperature range: 14 to 122°F (-10 to 50°C)

y Weight: 1.50 oz (42.5 g)

Quick-Start Circuit

Vdd = microcontroller voltage supply

Vservo = 4 to 6 VDC, regulated or battery (See Board of Education Servo Header Connection Diagram, page 2 )

I/O = PWM TTL or CMOS output signal, 3.3 to 5 V, not to exceed Vservo + 0.2 V

Continuous Rotation Servo Microcontroller

GND

Vdd

Vservo

White

Vss

I/O

Red

Black

Vdd

Summary of content (6 pages)

PAGE 1
Web Site: www.parallax.com Forums: forums.parallax.com Sales: sales@parallax.com Technical: support@parallax.com Office: (916) 624-8333 Fax: (916) 624-8003 Sales: (888) 512-1024 Tech Support: (888) 997-8267 Parallax Continuous Rotation Servo (#900-00008) The Parallax Standard Servo is ideal for robotics and basic movement projects.
PAGE 2
Device Information The Parallax continuous rotation servo relies on pulse width modulation to control the speed and direction of the servo shaft. Before utilizing the servo in a project, it is important to calibrate the center position of the servo in order to define the point where the servo is at rest (see Calibration – “Center” the Servo below). Specifications Pin Name 1 (White) 2 (Red) 3 (Black) Signal Vservo Vss Description Minimum Input; TTL or CMOS 3.3 Power Supply 4.
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BASIC Stamp Calibration Code - for all BS2 models √ √ Connect the servo to BASIC Stamp 1/O pin P12, or update the ToServo PIN declaration. Run the program, and gently twist the potentiometer adjustment screw until the servo does not turn or vibrate. NOTE: Calibrating the servo may take some patience. The potentiometer is very sensitive so a very light touch will be required. ' {$STAMP BS2} ' {$PBASIC 2.
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Communication Protocol The Parallax Continuous Rotation Servo is controlled through pulse width modulation, where the rotational speed and direction are determined by the duration of the pulse. In order for smooth rotation, the servo needs a 20 ms pause between pulses. Below is a sample timing diagram for a centered servo: As the length of the pulse decreases from 1.
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BASIC Stamp Programming Examples PBASIC has a PULSOUT command that sets the I/O Pin to an output and sends a pulse of the specified Duration. Since the servo needs this pulse refreshed every 20 ms for continuous operation, the PULSOUT command is put in a counted FOR…NEXT loop to sustain continuous operation for the specified number of cycles. PULSOUT Pin, Duration Different BASIC Stamp modules use different units for the PULSOUT command's Duration argument.
PAGE 6
Propeller Application The program below uses counter modules to rotate the servo first clockwise at full speed for 2 seconds, then rests for 2 seconds, and rotates counterclockwise at full speed for another 2 seconds. This code can also be downloaded from the 900-00008 product page. ServoRotation.spin CON _clkmode = xtal1 + pll16x _xinfreq = 5_000_000 ' System clock → 80 MHz PUB CenterServo | tInc, tc, tCtr, tCw, tCcw, t ctra[30..26] := %00100 ctra[8..