Kinetic Actuator Circuits

There are a variety of motors in circuitry, such as direct current, stepper, and servo motors. There are a variety of ways of driving these motors, via relays, transistors, chips or straight from an Arduino. 

Starting with the most basic demonstration of controlling the on/off function, we will use a solenoid with a TIP122 Transistor. 

1.1 Schematics for Solenoid driven by a TIP122 

1.2 Photo of solenoid driven by TIP122

By following this schematic and using the Arduino Blink code (File > examples > basics > blink). Doing this it should turn the solenoid on and off. *note 100k resistor. 

Now let's do the same function differently, by using a relay. This does the same action but through a mechanical action vs. an electrical one. 

2.1 Schematics for Solenoid/DC motor driven by a relay

2.2 Photo Example of Relay DC motor

This semantic can be completed with either a solenoid or a DC motor. We will use the same code as before. What this does is it triggers a switch much like in a solenoid to complete a circuit. 

So that maybe too simple for what you need to accomplish. So let's try adjusting the speed of the motor instead. 

3.1 Schematics for DC Motor driven by TIP122

3.2 Photo of DC motor driven by TIP122

By using the transistor we are able to alter the amount of power that the TIP122 emits, changing the speed of the motor. 

3.3 Code for Motor 

int motorPin = 13; //Motor pin

void setup(){

 pinMode(motorPin, OUTPUT); //establish output

}

void loop() {

 for(int motorValue = 0 ; motorValue <= 255; motorValue +=5){ //accelleration speed and peak

 analogWrite(motorPin, motorValue);  //drive motor from pin 13, at motor speed (motorValue)

 delay(30);    

 }

 for(int motorValue = 255 ; motorValue >= 0; motorValue -=5){ //decelleration spped and bottom

 analogWrite(motorPin, motorValue); //drive motor from pin 13, at motor speed (motorValue)

 delay(30);      

 }

}

4.2 Photo of L293D Chip driving motor

The TIP122 isn't the only way to drive through this motor, the L293D chip is a way to drive 2 motors with 1 tool. 

4.1 Scematic for driving DC motor with L293D Chip

   

4.3 CODE

int motorPin = 8; //two imputs are required (one)

int motorPin2 = 7; // imput 2

void setup(){

pinMode(motorPin, OUTPUT); //establish outputs

pinMode(motorPin2, OUTPUT); //establish outputs

}

void loop() {

 digitalWrite(motorPin, HIGH);   // turn the motor on (HIGH is the voltage level)

 delay(1000);                       // wait for a second

 digitalWrite(motorPin, LOW);    // turn the motor off by making the voltage LOW

 delay(1000);

 digitalWrite(motorPin2, HIGH);   // turn the motor on (HIGH is the voltage level)

 delay(1000);                       // wait for a second

 digitalWrite(motorPin2, LOW);    // turn the motor off by making the voltage LOW

 delay(1000);

}

Now lets move onto 2 very different motors, the servo and bipolar stepper. The hobby servo is something we can drive right from the arduino. Like so...

5.1 Servo Motor driven by Arduino

    

    

By using code built into Arduino (file > Examples > Servo > Sweep) we will be able to drive this motor up to 180 degrees.

Finally, the stepper motor requires a special driver, in this case, we will be using the A4988 driver chip. 

6.1 Stepper motor driven by A4988 Chip

6.2 Stepper driven by A4988 Chip

The code we can follow to drive this motor is as follows. sourced from Dejan

const int stepPin = 3; 

const int dirPin = 4; 

 

void setup() {

  // Sets the two pins as Outputs

  pinMode(stepPin,OUTPUT); 

  pinMode(dirPin,OUTPUT);

}

void loop() {

  digitalWrite(dirPin,HIGH); // Enables the motor to move in a particular direction

  // Makes 200 pulses for making one full cycle rotation

  for(int x = 0; x < 200; x++) {

    digitalWrite(stepPin,HIGH); 

    delayMicroseconds(500); 

    digitalWrite(stepPin,LOW); 

    delayMicroseconds(500); 

  }

  delay(1000); // One second delay

  

  digitalWrite(dirPin,LOW); //Changes the rotations direction

  // Makes 400 pulses for making two full cycle rotation

  for(int x = 0; x < 400; x++) {

    digitalWrite(stepPin,HIGH);

    delayMicroseconds(500);

    digitalWrite(stepPin,LOW);

    delayMicroseconds(500);

  }

  delay(1000);

}

That concludes all of the motors, here is a compilation of videos that show these motors functioning.