TI Stellaris and 28byj-48

I had 2 impulsive buying of paperweights collecting dust – TI Stellaris Launchpad and 28byj-48.

The reason for purchase in both cases was dirt-cheap price.

Well, Stellaris is no longer a paperweight – thanks to the guys who wrote Energia

I plug thing together and it did not work. I swapped wires to inputs 1 and 2 and it started spinning. Why is that? I’m not sure, but I have noticed that LEDs on the control board fire in the wrong order, and I foxed it with swapping wires. Now it spins OK.

stellaris

You can see 3 LED ON – it is side effect of digital camera long exposure time. Only 1 or 2 LEDs are ON at a time.

How I’m going to use it? I have no idea. Perhaps, it will go to back to the shelve.

See source code after the break. I did not write it – I found it on the internet and tweaked a bit.

// This Arduino example demonstrates bidirectional operation of a
// 28BYJ-48, which is readily available on eBay, using a ULN2003
// interface board to drive the stepper. The 28BYJ-48 motor is a 4-
// phase, 8-beat motor, geared down by a factor of 68. One bipolar
// winding is on motor pins 1 & 3 and the other on motor pins 2 & 4.
// Refer to the manufacturer’s documentation of Changzhou Fulling
// Motor Co., Ltd., among others. The step angle is 5.625/64 and the
// operating Frequency is 100pps. Current draw is 92mA. In this
// example, the speed and direction of the stepper motor is determined
// by adjusting a 1k-ohm potentiometer connected to Arduino pin A2.
// When the potentiometer is rotated fully counterclockwise, the motor
// will rotate at full counterclockwise speed. As the potentiometer is
// rotated clockwise, the motor will continue to slow down until is
// reaches its minimum speed at the the potentiometer’s midpoint value .
// Once the potentiometer crosses its midpoint, the motor will reverse
// direction. As the potentiometer is rotated further clockwise, the speed
// of the motor will increase until it reaches its full clockwise rotation
// speed when the potentiometer has been rotated fully clockwise.
////////////////////////////////////////////////

//declare variables for the motor pins
int motorPin1 = PA_2; // Blue – 28BYJ48 pin 1
int motorPin2 = PA_3; // Pink – 28BYJ48 pin 2
int motorPin3 = PA_4; // Yellow – 28BYJ48 pin 3
int motorPin4 = PA_5; // Orange – 28BYJ48 pin 4
// Red – 28BYJ48 pin 5 (VCC)

int motorSpeed = 0; //variable to set stepper speed

//////////////////////////////////////////////////////////////////////////////
void setup() {
//declare the motor pins as outputs
pinMode(motorPin1, OUTPUT);
pinMode(motorPin2, OUTPUT);
pinMode(motorPin3, OUTPUT);
pinMode(motorPin4, OUTPUT);
Serial.begin(9600);
motorSpeed = 10;
}

//////////////////////////////////////////////////////////////////////////////
void loop(){

clockwise(); //go to the ccw rotation function

}

//////////////////////////////////////////////////////////////////////////////
//set pins to ULN2003 high in sequence from 1 to 4
//delay “motorSpeed” between each pin setting (to determine speed)

void counterclockwise (){
// 1
digitalWrite(motorPin1, HIGH);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, LOW);
delay(motorSpeed);
// 2
digitalWrite(motorPin1, HIGH);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, LOW);
delay (motorSpeed);
// 3
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, LOW);
delay(motorSpeed);
// 4
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin4, LOW);
delay(motorSpeed);
// 5
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin4, LOW);
delay(motorSpeed);
// 6
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin4, HIGH);
delay (motorSpeed);
// 7
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, HIGH);
delay(motorSpeed);
// 8
digitalWrite(motorPin1, HIGH);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, HIGH);
delay(motorSpeed);
}

//////////////////////////////////////////////////////////////////////////////
//set pins to ULN2003 high in sequence from 4 to 1
//delay “motorSpeed” between each pin setting (to determine speed)

void clockwise(){
// 1
digitalWrite(motorPin4, HIGH);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, LOW);
delay(motorSpeed);
// 2
digitalWrite(motorPin4, HIGH);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, LOW);
delay (motorSpeed);
// 3
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, LOW);
delay(motorSpeed);
// 4
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin1, LOW);
delay(motorSpeed);
// 5
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin1, LOW);
delay(motorSpeed);
// 6
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin1, HIGH);
delay (motorSpeed);
// 7
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, HIGH);
delay(motorSpeed);
// 8
digitalWrite(motorPin4, HIGH);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, HIGH);
delay(motorSpeed);
}

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