How to Control 8 Servo in Arduino Uno

how to control 8 servo in arduino uno

What is an Arduino used for?

Arduino is an open-source electronics platform based on easy-to-use hardware and software. Arduino boards are able to read inputs - light on a sensor, a finger on a button, or a Twitter message - and turn it into an output - activating a motor, turning on an LED, publishing something online.

material used:-

arduino uno

servo(eight)

jumper wires

bread board mini

battery

circuit diagram

follow the circuit

If you are like me, then you knew very little about servo motors, and how to use them, so we should start from the beginning. A Servo motor uses pulse width modulation (pwm) from a microcontroller or a 555 timing IC (or something different I haven't heard about) to know what position to move its horn to. They can move both clockwise or counterclockwise thanks to an H bridge which is hardwired into them. Most Servos, unlike conventional electric motors do not move in continuous rotations. the standard servo moves anywhere between 0 and 180 degrees, which make them useful for animatronics and robotics. The servo has three wires coming out of it which usually ends in a female jack. the wire colors are black, which gets connected to ground, red which gets connected to the positive power supply, and white or yellow which gets connected to the output of the microcontroller or 555 IC, and receives the pwm. Okay now that you know the basics, lets get started

the first thing that you should do is make sure your servo motor is working. because the servos wires end in a female header, you cannot plug it into the arduino (unless you have a shield. insert solid core wires into the headers, so you can attach it to the pins of the arduino (or anything else). When you downloaded your programming environment for arduino, it should have two examples for the servo. The one we are going to use first is called sweep. Go to the "open" icon next to save near the top of the window on the environment. click on it, and a list of files should come up. go down to the one that says servo, and put your mouse over it. two files should come out of it. one called "sweep" and one called "knob". click on the one called sweep, compile the code and upload it to your board. if everything is connected correctly, the servo should begin to go back and forth from 0 to 180 degrees. If you cannot find the code, copy this:

// Sweep

// by BARRAGAN <http://barraganstudio.com>

// This example code is in the public domain.

#include <Servo.h>

Servo myservo; // create servo object to control a servo

               // a maximum of eight servo objects can be created

int pos = 0;   // variable to store the servo position

void setup()

{

 myservo.attach(9); // attaches the servo on pin 9 to the servo object

}

void loop()

{

 for(pos = 0; pos < 180; pos += 1) // goes from 0 degrees to 180 degrees

 {                                 // in steps of 1 degree

   myservo.write(pos);             // tell servo to go to position in variable 'pos'

   delay(15);                      // waits 15ms for the servo to reach the position

 }

 for(pos = 180; pos>=1; pos-=1)    // goes from 180 degrees to 0 degrees

 {                               

   myservo.write(pos);             // tell servo to go to position in variable 'pos'

   delay(15);                      // waits 15ms for the servo to reach the position

 }

}

be sure to plug in the white wire to digital pin 9, the black wire to one of the ground pins on arduino, and the red wire to the 5v pin on the arduino board.

Servo motors are great devices that can turn to a specified position.

Usually, they have a servo arm that can turn 180 degrees. Using the Arduino, we can tell a servo to go to a specified position and it will go there. As simple as that!

Servo motors were first used in the Remote Control (RC) world, usually to control the steering of RC cars or the flaps on a RC plane. With time, they found their uses in robotics, automation, and of course, the Arduino world.

Here we will see how to connect a servo motor and then how to turn it to different positions.

The first motor I ever connected to an Arduino, seven years ago, was a Servo motor. Nostalgic moment over, back to work! the first thing that you should do is make sure your servo motor is working. because the servos wires end in a female header, you cannot plug it into the arduino (unless you have a shield. insert solid core wires into the headers, so you can attach it to the pins of the arduino (or anything else). When you downloaded your programming environment for arduino, it should have two examples for the servo. The one we are going to use first is called sweep. Go to the "open" icon next to save near the top of the window on the environment. click on it, and a list of files should come up. go down to the one that says servo, and put your mouse over it. two files should come out of it. one called "sweep" and one called "knob". click on the one called sweep, compile the code and upload it to your board. if everything is connected correctly, the servo should begin to go back and forth from 0 to 180 degrees. upload the program to arduino and follow the circuit diagram. asper arduino servo should be connect to pwm pin as 3,6,5,9,10,11.so these are six pins we want to connect the servo but we want extra pins so, I have connected 8 pins to arduino .0,1 pins stands for communication us IoT ,hc05,etc.

this project is the step for rocket thrust vector !

thank for visiting my project !

about servo:-

In control engineering a servomechanism, usually shortened to servo, is an automatic device that uses error-sensing negative feedback to correct the action of a mechanism.[1] On displacement-controlled applications, it usually includes a built-in encoder or other position feedback mechanism to ensure the output is achieving the desired effect.[2]

Main articles: Servomotor and servo (radio control)

Industrial servomotor

The grey/green cylinder is the brush-type DC motor. The black section at the bottom contains the planetary reduction gear, and the black object on top of the motor is the optical rotary encoder for position feedback.

Small R/C servo mechanism.

1. electric motor

2. position feedback potentiometer

3. reduction gear

4. actuator arm

A servomotor is a specific type of motor that is combined with a rotary encoder or a potentiometer to form a servomechanism. This assembly may in turn form part of another servomechanism. A potentiometer provides a simple analog signal to indicate position, while an encoder provides position and usually speed feedback, which by the use of a PID controller allow more precise control of position and thus faster achievement of a stable position (for a given motor power). Potentiometers are subject to drift when the temperature changes whereas encoders are more stable and accurate.

Servomotors are used for both high-end and low-end applications. On the high end are precision industrial components that use a rotary encoder. On the low end are inexpensive radio control servos (RC servos) used in radio-controlled models which use a free-running motor and a simple potentiometer position sensor with an embedded controller. The term servomotor generally refers to a high-end industrial component while the term servo is most often used to describe the inexpensive devices that employ a potentiometer. Stepper motors are not considered to be servomotors, although they too are used to construct larger servomechanisms. Stepper motors have inherent angular positioning, owing to their construction, and this is generally used in an open-loop manner without feedback. They are generally used for medium-precision applications.

RC servos are used to provide actuation for various mechanical systems such as the steering of a car, the control surfaces on a plane, or the rudder of a boat. Due to their affordability, reliability, and simplicity of control by microprocessors, they are often used in small-scale robotics applications. A standard RC receiver (or a microcontroller) sends pulse-width modulation (PWM) signals to the servo. The electronics inside the servo translate the width of the pulse into a position. When the servo is commanded to rotate, the motor is powered until the potentiometer reaches the value corresponding to the commanded position.

history:-

A servomotor is a specific type of motor that is combined with a rotary encoder or a potentiometer to form a servomechanism. This assembly may in turn form part of another servomechanism. A potentiometer provides a simple analog signal to indicate position, while an encoder provides position and usually speed feedback, which by the use of a PID controller allow more precise control of position and thus faster achievement of a stable position (for a given motor power). Potentiometers are subject to drift when the temperature changes whereas encoders are more stable and accurate.

Servomotors are used for both high-end and low-end applications. On the high end are precision industrial components that use a rotary encoder. On the low end are inexpensive radio control servos (RC servos) used in radio-controlled models which use a free-running motor and a simple potentiometer position sensor with an embedded controller. The term servomotor generally refers to a high-end industrial component while the term servo is most often used to describe the inexpensive devices that employ a potentiometer. Stepper motors are not considered to be servomotors, although they too are used to construct larger servomechanisms. Stepper motors have inherent angular positioning, owing to their construction, and this is generally used in an open-loop manner without feedback. They are generally used for medium-precision applications.

RC servos are used to provide actuation for various mechanical systems such as the steering of a car, the control surfaces on a plane, or the rudder of a boat. Due to their affordability, reliability, and simplicity of control by microprocessors, they are often used in small-scale robotics applications. A standard RC receiver (or a microcontroller) sends pulse-width modulation (PWM) signals to the servo. The electronics inside the servo translate the width of the pulse into a position. When the servo is commanded to rotate, the motor is powered until the potentiometer reaches the value corresponding to the commanded position.

Power-assisted ship steering systems were early users of servomechanisms to ensure the rudder moved to the desired position.

James Watt's steam engine governor is generally considered the first powered feedback system. The windmill fantail is an earlier example of automatic control, but since it does not have an amplifier or gain, it is not usually considered a servomechanism.

The first feedback position control device was the ship steering engine, used to position the rudder of large ships based on the position of the ship's wheel. John McFarlane Gray was a pioneer. His patented design was used on the SS Great Eastern in 1866. Joseph Farcot may deserve equal credit for the feedback concept, with several patents between 1862 and 1868.[4]

The telemotor was invented around 1872 by Andrew Betts Brown, allowing elaborate mechanisms between the control room and the engine to be greatly simplified.[5] Steam steering engines had the characteristics of a modern servomechanism: an input, an output, an error signal, and a means for amplifying the error signal used for negative feedback to drive the error towards zero. The Ragonnet power reverse mechanism was a general purpose air or steam-powered servo amplifier for linear motion patented in 1909.[6]

Electrical servomechanisms were used as early as 1888 in Elisha Gray's Telautograph.

Electrical servomechanisms require a power amplifier. World War II saw the development of electrical fire-control servomechanisms, using an amplidyne as the power amplifier. Vacuum tube amplifiers were used in the UNISERVO tape drive for the UNIVAC I computer. The Royal Navy began experimenting with Remote Power Control (RPC) on HMS Champion in 1928 and began using RPC to control searchlights in the early 1930s. During WW2 RPC was used to control gun mounts and gun directors.

Modern servomechanisms use solid state power amplifiers, usually built from MOSFET or thyristor devices. Small servos may use power transistors.

The origin of the word is believed to come from the French "Le Servomoteur" or the slavemotor, first used by J. J. L. Farcot in 1868 to describe hydraulic and steam engines for use in ship steering.[7]

The simplest kind of servos use bang–bang control. More complex control systems use proportional control, PID control, and state space control, which are studied in modern control theory.