Introduction

A servomotor is an electrical device, which can push or rotate an object with great precision. If you want to rotate and object at some specific angles or distance, then you use servomotor. It is just made up of simple motor, which run through servomechanism.

Leaning outcome:

• Using servo motor with Magicbit

Theory

Servo motor works on the PWM (Pulse Width Modulation) principle, which means its angle of rotation, is controlled by the duration of pulse applied to its control PIN. Servomotor is made up of DC motor, which is controlled by a variable resistor (potentiometer), and some gears. Servomotors control position and speed very precisely. Now a potentiometer can sense the mechanical position of the shaft. Hence, it couples with the motor shaft through gears. The current position of the shaft is converted into electrical signal by potentiometer, and is compared with the command input signal. In modern servomotors, electronic encoders or sensors sense the position of the shaft. A pulse of 1ms will move the shaft anticlockwise at -90 degree, a pulse of 1.5ms will move the shaft at the neutral position that is 0 degree and a pulse of 2ms will move shaft clockwise at +90 degree.

Figure 1:PWM Signals for various angles

Methodology

For implement this project first connect the magic servo motor to the Magicbit. Then Drag and Drop following blocks from block palette in to the scripting area to create the following Script.

Script

Explanation

This program rotates the servo motor by 180 degrees with 45 degrees step at a time. The program starts by clicking the green flag on the MagicCode interface. The servo should be connected to a PWM pin and, in this example, the servo has connected to Magicbit Pin 32. According to the script at first, the servo rotates 45 degrees and stays one second at that position. In the same way, it rotates up to 180 degrees and stops.