I2C ATSAME70N20

#include "I2C.h"

#include "sam.h"

#include "same70n20.h"

#define I2C_CLK_SPEED   100000

#define I2C_MODULE    TWIHS0

void I2C_Master_Init(void){

  /* Enable TWI peripheral clock */

  PMC->PMC_PCER0 = PMC_PCER0_PID19;

  /* Configure PIOA Pins for I2C */

  PIOA->PIO_PDR = (PIO_PDR_P3 | PIO_PDR_P4);

    PIOA->PIO_ABCDSR[0] &= ~(PIO_ABCDSR_P3 | PIO_ABCDSR_P4);

    PIOA->PIO_ABCDSR[1] &= ~(PIO_ABCDSR_P3 | PIO_ABCDSR_P4);

  /* Configure TWI clock waveform generator */

  I2C_MODULE->TWIHS_CWGR =  TWIHS_CWGR_CLDIV(((SystemCoreClock / (2 * I2C_CLK_SPEED))) - 3) |

                TWIHS_CWGR_CHDIV(((SystemCoreClock / (2 * I2C_CLK_SPEED))) - 3) |

                TWIHS_CWGR_CKDIV(0);          

  /* Enable TWI module */

  I2C_MODULE->TWIHS_CR = TWIHS_CR_SWRST;

  I2C_MODULE->TWIHS_CR = TWIHS_CR_SVDIS;

  I2C_MODULE->TWIHS_CR = TWIHS_CR_MSEN; 

}

uint8_t I2C_write_data(uint8_t* data, uint8_t length, uint8_t sendStopCondition, uint8_t address) {

  //Set slave address    

  I2C_MODULE->TWIHS_MMR = TWIHS_MMR_IADRSZ(0);

  I2C_MODULE->TWIHS_MMR |= TWIHS_MMR_DADR(address);

  I2C_MODULE->TWIHS_MMR &=~ TWIHS_MMR_MREAD;  

  I2C_MODULE->TWIHS_CR = TWIHS_CR_MSEN;

    for (uint8_t i = 0; i < length; i++){

    //send data

         I2C_MODULE->TWIHS_THR = data[i];

         while(!(I2C_MODULE->TWIHS_SR & TWIHS_SR_TXRDY));

  }

  //if we have to send stop condition (instead of a new start condition)

  if(sendStopCondition){

    /* Send stop condition */

    I2C_MODULE->TWIHS_CR = TWIHS_CR_STOP;

    while (!(I2C_MODULE->TWIHS_SR & TWIHS_SR_TXCOMP));

    }

  return I2C_NO_ERROR_DETECTED;

}