mpr083.c

LED APPLICATION MCF51JM

/*!
 * \file    mpr083.c
 * \brief   Simple driver MPR083 using I2C
 * \version $Revision: 1.1 $
 * \author  Anthony Huereca
 */

 #include "mpr083.h"

/*********************************** Variables ***********************************/
unsigned char SlaveID;
unsigned char MasterTransmission;

/*******************************************************************/
/*!
 * I2C Initialization
 * Set Baud Rate and turn on I2C
 */
void init_I2C(void) 
{
  if(!PTGD_PTGD1) /* If connected to USB and thus 12MHz bus */ 
  {
    IIC1F  = 0x14;       /* set MULT and ICR */     
  } 
  else           /* 750kHz bus */
  {
    IIC1F  = 0x00;       /* set MULT and ICR */   
  }
  IIC1C1 = 0x80;       /* enable IIC */ 
}

/*******************************************************************/
/*!
 * MPR083 Initialization
 */
void MPR083_init(void) 
{   
  /* Delay Loop to ensure MPR083 is powered up */
  int i;

  for(i=0;i<10000;i++) {
    asm("nop");
  }

  /* Turn on I2C Clock */
  SCGC1_IIC1=1;
  
  /* Configure I2C */ 
  init_I2C();

  /* Turn on ATTN Pin */
  PTCDD_PTCDD6=1; 
  ATTN=1;

  /* Ensure MPR083 is awake */
  TOGGLE_ATTN

  /* Put in Stop 1 Mode for initial Config */
  MPR083WriteRegister(CONFIGURATION_REGISTER,0x14);
  
  /* Set Sensitivity Threshold to 0x3F */
  MPR083WriteRegister(SENSITIVITY_REGISTER,0x3F);
  
  /* Turn off Sounder */
  MPR083WriteRegister(SOUNDER_CONFIGURATION_REGISTER,0x00);
  
  /* Sound On, Auto Calibration On, Touch and Release Buffer On, Sensor On */
  MPR083WriteRegister(ROTARY_CONFIGURATION_REGISTER, 0x9D); 

  /* Set 5ms Master Clock */
  MPR083WriteRegister(MASTER_TICK_COUNTER_REGISTER,0x00);
      
  /* TASP Multiplier to 2 */
  MPR083WriteRegister(TOUCH_ACQUISITION_SAMPLE_PERIOD_REGISTER,0x01);
  
  /* No Delay for Touches */  
  MPR083WriteRegister(LOW_POWER_CONFIGURATION_REGISTER, 0x00);     

  /* Turn on MPR083 IRQ and put in Run 2 Mode */  
  MPR083WriteRegister(CONFIGURATION_REGISTER,0x13);  

  /* Turn off I2C Clock */
  SCGC1_IIC1=0;
  
  /* Turn on IRQ. Falling edge and low-level triggered */
  IRQSC=0x53;   
}
   
/*******************************************************************/
/*!
 * IRQ Service Routine
 * Toggles the Attention pin to wake up MPR083 for I2C communications
 * Then reads Status register, clears FIFO buffer, and put back in low power mode
 * Only executes when button is either pushed or released
 */
interrupt VectorNumber_Virq void IRQ_ISR (void) 
{
  byte fault;
  byte touch;

  /* Turn on I2C Clock and Re-init I2C */
  SCGC1_IIC1=1;
  init_I2C();  
  
  /* Put MPR083 into Run1 Mode for I2C Communication */
  TOGGLE_ATTN 

  /* Turn off interrupts */
  MPR083WriteRegister(CONFIGURATION_REGISTER,0x15);

  /* Check for fault */
  fault=u8MPR083ReadRegister(FAULT_REGISTER);
  
  if(fault&0x00000003) 
  { 
    //ignore interrupt generated by fault
  } 
  else
  {  
    /* IRQ generated by touch. Get current status of touch pad */
    touch=u8MPR083ReadRegister(ROTARY_STATUS_REGISTER);    
    
    /* See if IRQ caused by button touch or button release */
    
    /* If button touch */
    if(touch&0x10) 
    { 
      /* Send out value to left LED's */
      PTED=~((touch&0x0F)+1);
      
      /* Turn on all rows */
      PTAD=0x1F;
    } 
    /* Else if no button is touched */
    else 
    {
      /* Turn off LED's */
      PTED=~(0x00);
      PTAD=0x00;
    }
  }

  /* Clear interrupt signal */   
  while(IRQSC_IRQF) 
  {
    MPR083WriteRegister(FAULT_REGISTER,0x00);
    MPR083WriteRegister(FIFO_REGISTER,0x00);      
    IRQSC_IRQACK=1; 
  } 
    
  /* Put back in Low Power Mode */
  MPR083WriteRegister(CONFIGURATION_REGISTER,0x13);
 
  /* Turn off I2C Clock */ 
  SCGC1_IIC1=0;
}



/*******************************************************************/
/*!
 * Pause Routine
 */ 
void Pause(void){
    int n;
    for(n=1;n<50;n++) {
      asm("nop");
    }
}


/*******************************************************************/
/*!
 * Start I2C Transmision
 * @param SlaveID is the 7 bit Slave Address
 * @param Mode sets Read or Write Mode
 */
void IIC_StartTransmission (unsigned char SlaveID,unsigned char Mode)
{
  if(Mode == MWSR)
  {      
    /* set transmission mode */
    MasterTransmission = MWSR;
  }
  else
  {
    /* set transmission mode */
    MasterTransmission = MRSW;
  }
    
  /* shift ID in right possition */
  SlaveID = (byte) MPR083_I2C_ADDRESS << 1; 
  
  /* Set R/W bit at end of Slave Address */
  SlaveID |= (byte)MasterTransmission;

  /* send start signal */
  i2c_Start();

  /* send ID with W/R bit */
  i2c_write_byte(SlaveID);
}


/*******************************************************************/
/*!
 * Read a register from the MPR083
 * @param u8RegisterAddress is Register Address
 * @return Data stored in Register
 */
byte u8MPR083ReadRegister(byte u8RegisterAddress)
{
  byte result, result2;
  
  /* Set Register Pointer on MPR083 */
  IIC_StartTransmission(SlaveID,MWSR);  
  i2c_Wait();
  
  IIC1D = u8RegisterAddress;
  i2c_Wait();    
  
  i2c_Stop();     
  
  Pause();
          
  /* Request data from Register */         
  IIC_StartTransmission(SlaveID,MRSW);
  i2c_Wait();
   
  i2c_EnterRxMode(); 
  result2 = IIC1D;
  i2c_Wait();   
  
  result = IIC1D;
  i2c_DisableAck();
  i2c_Wait(); 
   
  i2c_Stop(); 
  result2 = IIC1D;
 
  Pause();

  return result;
}

/*******************************************************************/
/*!
 * Write a byte of Data to specified register on MPR083
 * @param u8RegisterAddress is Register Address
 * @param u8Data is Data to write
 */
void MPR083WriteRegister(byte u8RegisterAddress, byte u8Data)
{
  /* send data to slave */
  IIC_StartTransmission(SlaveID,MWSR);  
  i2c_Wait();
  
  IIC1D = u8RegisterAddress;
  i2c_Wait();
  
  IIC1D = u8Data;
  i2c_Wait();    
  
  i2c_Stop();        

  Pause();
}