AVR Freaks

/*! \file *******************************************************************
*
* File              : DC_MotorControler.c
* Compiler          : GCC (WinAVR)
* Revision          : 1.0
* Date              : 06/21/09
* Updated by        : Ben Nemec
*
* Supported devices : All devices with a PWM can be used.
*                     The example is written for ATmega48
*
* Description       : controll speed of a brush type DC motor using PWM and
*                    an H-bridge circuit, control from UART, SPI or TWI port                   
*
****************************************************************************/

#include 
#include 
#include 
#include 
#include "DC_MotorController.h"
#include "UART.h"
#include "ADC.h"

//constants
#define FALSE  0
#define TRUE   (!FALSE)

// Private Macro definitions
#define  sbi(port,bit)  (port |= (1<<bit))   //set bit in port
#define  cbi(port,bit)  (port &= ~(1<<bit))  //clear bit in port
#define  PWM   PD6
#define  HBp   4

#define  CNTLA PORTC
   #define  FAULT PC2   //fault signal input from A3940

   #define  RSTn  0     //pwer down & clear latched faults
   #define  PHASE 1     //motor direction control
//   #define  ENBL  2     //high allows direct control of driver outputs via phase
   #define  SR    PC3   //sychornous rectification
   #define  MODE  4     //current decay mode
  


// private function prototypes:
void init_counter(void);
void InitMotorControler (void);


/* Main */
int main( void )
{ 
   //dissable all interrupts
   cli();

   //crank clock up to 8MHz see datasheet doc2545 p35
   //CLKPR = 0x80; //must write CLKPCE = 1 at same time as rest to 0   
   //CLKPR = 0x00; //program to divide by 1
   // not calibrating osc.

   //configure heartbeat pin:
   sbi (DDRD, HBp);
   sbi (PORTD, HBp);
   volatile uint16_t hrtBtCounter = 0; 
   volatile uint16_t i;
   volatile uint8_t data;


   for (i = 0; i< 10; i++)
   {
      for (hrtBtCounter = 0; hrtBtCounter < 50; hrtBtCounter ++); 
      cbi (PORTD, HBp);
   
      for (hrtBtCounter = 0; hrtBtCounter < 50; hrtBtCounter ++); 
      sbi (PORTD, HBp);
   }
   //
   cbi (PORTD, HBp);

   init_counter();
   init_adc();                    
   USART_Init(25);
   SendNTString("UART Initialized\n\r");
   InitMotorControler();

   hrtBtCounter = 0;
   for (;;)  //ever
   {
      

      data = USART_Receive();

      if (data >= 0x30 && data <= 0x39)
         OCR0A = (data - 0x30) * 28; 
         
   }
   return 0;
}

//*************************  init_counter  **********************************
/* 
Phase Correct PWM Mode (WGM02:0 = 1), TOP = 0xFF
non-inverted PWM; COM0x1:0 bits = two.


   0 0 1 clkI/O/(No prescaling)

*/
void init_counter(void)
{
   cbi (PRR, PRTIM0);

   //setup counter frequency
   //0x24 (0x44) TCCR0A [COM0A1 COM0A0 COM0B1 COM0B0 "“ "“ WGM01 WGM00]
   TCCR0A = 0x81;    // [  1      0      0      0    0 0   0     1
   //0x25 (0x45) TCCR0B [FOC0A FOC0B "“ "“ WGM02 CS02 CS01 CS00]
   TCCR0B = 0x01;    // [  0     0   0 0   0     0    0    1 ]
}


//*************************  InitMotorControler  ***************************/
void InitMotorControler (void)
{
   init_counter();      // Initiate and starts Counter 0 for PWM
   sbi(DDRD, PWM);      // set pin as output for PWM
   sbi(DDRC, RSTn);        // set port pin directions for control
   sbi(DDRC, PHASE);        // set port pin directions for control
//   sbi(DDRC, ENBL);        // set port pin directions for control
//   sbi(DDRC, SR);        // set port pin directions for control
//   sbi(DDRC, MODE);        // set port pin directions for control

   //powerup the Allegro A3940 according to the app note.
//   cbi(CNTLA, ENBL);        
   sbi(CNTLA, RSTn);
   _delay_us(10);      //allow time for vregs in A3940 to come up.  
//   sbi(CNTLA, SR);         
//   sbi(CNTLA, MODE);       

}