Controlling DC motor using PIC18 - C codes

qwertyuiop415263 said:

which compiler you are using?

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lockman_akim said:

your ir sensor sent ON OFF signal?

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msab2006 said:

The IR sensor is a SHARP GP2XX series. Basically i need to use the ADC of the microcontroller since the sensor reads the the distance in analog form. It's takes a continuous distance reading with a range between 10-80cm. But i just want it to trigger at a certain range, say about 50cm.

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Sink0 said:

Is the motor Brushless or Brushed? How about the power?

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Tahmid said:

Hi,
I'm assuming you've successfully received the signal from the sensor. Therefore, you now need to use PWM - pulse width modulation - to control the motor. It is very easy. Read the datasheet of the PIC and the reference manual. If you don't understand, then post again, and I'll try to post a sample code that may help you.

Take a look at this project for reference:
PWM DC Motor Controller

Hope this helps.
Tahmid.

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Would it be easier if I used the MPLAB IDE compiler as opposed to the MikroC compiler?

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Thanks. Just a question, since I need to use the PWM, where does the ADC part come in? Is it possible for you to post a simple code for me to refer to? Would be of great help.

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//Program to generate 25kHz output at RC2(CCP1) pin
//Microcontroller: Microchip PIC18452
//Language: C
//Compiler: mikroC v8.20
//Programmer: Tahmid

void main (void){
     TRISC = 0;
     PORTC = 0;
     ADCON1 = 7;
     T2CON = 0;
     TMR2 = 0;
     PWM1_Init(25000); //25kHz
     PWM1_Change_Duty(128); //50% duty cycle
// Choose Duty cycle as such:
// PWM_Change_Duty(x);
// x = ( (Duty Cycle in %) / 100) * 255
// This should be read from the IR signal
// This would control the speed of the motor
     PWM1_Start(); //Start PWM
     while (1){ //Loop forever
// Whatever else might be needed to be done while PWM is running
     }
}

Tahmid said:

If you think so, but I think mikroC would be much easier.

You could send the signal to the controller through IR, so you wouldn't need ADC. But ADC is usually here to be used for reading a value off a pot and then adjusting the PWM duty cycle.

Code:

//Program to generate 25kHz output at RC2(CCP1) pin
//Microcontroller: Microchip PIC18452
//Language: C
//Compiler: mikroC v8.20
//Programmer: Tahmid

void main (void){
     TRISC = 0;
     PORTC = 0;
     ADCON1 = 7;
     T2CON = 0;
     TMR2 = 0;
     PWM1_Init(25000); //25kHz
     PWM1_Change_Duty(128); //50% duty cycle
// Choose Duty cycle as such:
// PWM_Change_Duty(x);
// x = ( (Duty Cycle in %) / 100) * 255
// This should be read from the IR signal
// This would control the speed of the motor
     PWM1_Start(); //Start PWM
     while (1){ //Loop forever
// Whatever else might be needed to be done while PWM is running
     }
}

If you just need to turn on/off the motor then you don't need this. PWM is needed only for variable duty cycle, ie, adjusting the motor speed. For simple on/off, you could use a port pin and a transistor/MOSFET and send 1 to the pin to turn motor on or 0 to turn motor off.

Hope this helps.
Tahmid.

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