File contents

/* ========================================
 *
 * Michael Smith
 * Dept. Materials Science and Metallurgy
 * University of Cambridge
 * 2016
 *
 * Matrix addressing scheme to control the brightness and flashing rate of 6 LEDs
 * using 2 PWM signals and 5 pins.
 * 
 *
 * ========================================
*/
#include <project.h>


/* ************** Define variables **************** */

uint16 delay_time = 1;  // Delay time in milliseconds, 1 is a reasonable value


int P[2][3] = {
    {250,250,250},      // Enter starting values of brightness from 1 - 254 for each LED
    {0,100,200}
};

int FlashRate[2][3] = {
    {0,0,0},            // Enter breathing rate. 0 = static
    {0,0,0}
};

/**************************************************************/


int main()
{
    
    
    CyGlobalIntEnable;  // Enable global interrupts
    PWM_Start();
    PWM_Enable();
    
  

    for(;;){                     // Forever loop
    
        
    int i,j,k;                   // Local variables to count iterations
        
    
    for(i=0; i<2; i++) {         // Nested for loops to cycle through the pattern array, changing the brightness as dictated by the flash rate
       
        for(j=0; j<3; j++){   
       
            P[i][j] = P[i][j] + FlashRate[i][j];        // Update brightness level of LED
           
            
            if (P[i][j] < 1){
            FlashRate[i][j] = - FlashRate[i][j];        // If the brightness is negative, reverse the sign of the flash rate and reset brightness to 1
            P[i][j] = 1;
            }
            
            
            if (P[i][j] > 255){
            FlashRate[i][j] = - FlashRate[i][j];        // If the brightness is greater than 255, reverse flash rate and rest brightness value.
            P[i][j] = 255;
            }
            
        }
    }
        
    
        
        
    
    for (k=0; k<5; k++){                                // Cycles through the LEDs 5 times for each brightness level
    ColumnsRegister_Write(6); // 110
    PWM_WriteCompare1(P[0][0]);
    PWM_WriteCompare2(P[1][0]);
    
    CyDelay(delay_time);                                // Delay so that the LED has chance to light up
    
   
    ColumnsRegister_Write(5); // 101
    PWM_WriteCompare1(P[0][1]);
    PWM_WriteCompare2(P[1][1]);
    
    CyDelay(delay_time);
    
    
    ColumnsRegister_Write(3); // 011
    PWM_WriteCompare1(P[0][2]);
    PWM_WriteCompare2(P[1][2]);
    
    CyDelay(delay_time);
    
    }    
    }
}


/* [] END OF FILE */