The Simple Labs' Servo Shield is a custom designed Shield to drive Servo Motors. The Shield Can drive upto 10 servo motors at a time. It was originally designed for our Quadbot Robot Kit (8 Servos) + Mini Pan and Tilt Kit (2 Servos). In addition to this, the servo shield has suitable pin outs to be able to Connect the Compound Eye IR Sensor.
Servo Motors - What are they?
Servo motors are dc motors with a servo mechanism that lets us control the precise position of the Shaft.
A servo mechanism is a error correction mechanism that senses the negative error and applies a correction accordingly.
There are many types of Servo Motors available - depending upon applications.
They are used in areas requiring position control. While the basic working of all the servo motors is almost similar, for the scope of this tutorial we shall stick to discussing RC Servo Motors or the type of Servo motors used in Robotics / Radio Control Projects.
A Servo motor constitutes of 4 parts - a DC motor, a Gear system, A Potentiometer(for sensing feedback) and a Control Circuit. Here the Control Circuit and the Potentiometer together form the Servo Mechanism.
The servo shield has Servo control pins on Arduino Digital Pins D2, D3, D4, D5, D6, D9, D10, D11, D12 & D13. Refer to the TOP Legend on the board "D + - " for the Orientation of the Servo Connector Connection.
Servo Motors - What are they?
Servo motors are dc motors with a servo mechanism that lets us control the precise position of the Shaft.
A servo mechanism is a error correction mechanism that senses the negative error and applies a correction accordingly.
There are many types of Servo Motors available - depending upon applications.
They are used in areas requiring position control. While the basic working of all the servo motors is almost similar, for the scope of this tutorial we shall stick to discussing RC Servo Motors or the type of Servo motors used in Robotics / Radio Control Projects.
A Servo motor constitutes of 4 parts - a DC motor, a Gear system, A Potentiometer(for sensing feedback) and a Control Circuit. Here the Control Circuit and the Potentiometer together form the Servo Mechanism.
So How do Servo Motors Work?
The Control Circuitry on the Servo motor drives the DC motor based on input signals it receives, The output shaft of the DC motor is connected to the gear assembly and the gear assembly is such that it moves the potentiometer when it rotates. The Control Circuitry gets feedback from this potentiometer and spins the DC motor to achieve the desired angle between 0 & 180 degrees. The range of movement of the potentiometer is mechanically restrained.
And How do we Control these Servo Motors?
To Control a servo we need to give it a pulse once every 20 milliseconds. The Duration of this pulse will determine the Servo Angle which we need to achieve. For most Servo's a Pulse duration of 1millisecond will set the shaft position to 0 degrees and a pulse duration of 2 milliseconds will set the shaft position to 180 degrees.
Controlling Servos with an Arduino
Arduino provides us with a servo control library that lets us control servos with ease. The library provides us with an option of writing both microseconds value and angle values. You can find more information on the library here - > Arduino Servo Library
Overview of the Servo Shield
The Servo Shield has clear pin mappings and polarity mappings for the Servos. It has a screw terminal for connecting an external power supply for the Servos. Servos require 4.8-6Volts and consume around 300-500milliamps. The Servo shield requires to be powered from an External Source for it to drive your servos.
Connect a Servo to D9 and an external Supply to the Battery Connector as Shown a 4xAA Battery Connector is used here in the image. The Servo shown in the image is part of the Quadbot Kit. If you are looking for a servo, you can check out the Tower Pro SG-5010
The Program
With the above setup you can load the 'Sweep' Program from within the Examples. This program is located at
File -> Examples -> Servo -> Sweep (Inside the Arduino IDE!)
