File content as of revision 17:833f1b69e11d:

#include "stm32f30x.h"
#include "stm32f3_discovery.h"
#include <stdio.h>
#include "stm32f3_discovery_lsm303dlhc.h"

#define GPIO_MODE_INPUT 0
#define GPIO_MODE_OUTPUT 1
#define GPIO_MODE_AF 2

#define GPIO_NO_PULL 0
#define GPIO_PULL_UP 1
#define GPIO_PULL_DOWN 2

#define GPIO_OUTPUT_PUSH_PULL 0

#define GPIO_SPEED_MEDIUM 1
#define GPIO_SPEED_LOW 0
#define GPIO_SPEED_HIGH 3

extern void gpio_set_mode(GPIO_TypeDef *g,int n,int mode);

extern void gpio_set_af(GPIO_TypeDef *g,int n,int af, int otype, int pupd, int speed);


void i2cInit() {
  RCC->APB1ENR |= RCC_APB1ENR_I2C1EN;
  RCC->AHBENR |= RCC_AHBENR_GPIOBEN;
  // configure GPIOPB6 and 7
  gpio_set_af(GPIOB,6,4,GPIO_OUTPUT_PUSH_PULL,GPIO_PULL_DOWN,GPIO_SPEED_LOW);
  gpio_set_af(GPIOB,7,4,GPIO_OUTPUT_PUSH_PULL,GPIO_PULL_DOWN,GPIO_SPEED_LOW);

  I2C1->TIMINGR = 0x00902025;
  I2C1->CR1 |= I2C_CR1_PE;

}

#define I2C_CR2_CLEAR_MASK ~(I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RELOAD | I2C_CR2_AUTOEND | I2C_CR2_RD_WRN | I2C_CR2_START | I2C_CR2_STOP)

void i2cWrite(int address, int reg, int val) {
    while(I2C1->ISR & I2C_ISR_BUSY);
    I2C1->CR2 = (I2C1->CR2 & I2C_CR2_CLEAR_MASK) | I2C_CR2_RELOAD | I2C_CR2_START | (1<<16) | address;
    while(!(I2C1->ISR & I2C_ISR_TXIS));
    I2C1->TXDR=reg;
    while(!(I2C1->ISR & I2C_ISR_TCR));
    I2C1->CR2 = (I2C1->CR2 & I2C_CR2_CLEAR_MASK) | I2C_CR2_AUTOEND | (1<<16) | address;
    while(!(I2C1->ISR & I2C_ISR_TXIS));
    I2C1->TXDR=val;
    while(!(I2C1->ISR & I2C_ISR_STOPF));
    I2C1->ICR = I2C_ICR_STOPCF;
}

void i2cRead(int address, int reg, uint8_t *data, int nbytes) {
    while(I2C1->ISR & I2C_ISR_BUSY);
    I2C1->CR2 = (I2C1->CR2 & I2C_CR2_CLEAR_MASK) | I2C_CR2_START | (1<<16) | address;
    while(!(I2C1->ISR & I2C_ISR_TXIS));
    if(nbytes>1) reg |= 0x80;
    I2C1->TXDR=reg;
    while(!(I2C1->ISR & I2C_ISR_TC));
    I2C1->CR2 = (I2C1->CR2 & I2C_CR2_CLEAR_MASK) | I2C_CR2_AUTOEND | I2C_CR2_START | I2C_CR2_RD_WRN | (nbytes<<16) | address;
    while(nbytes--) {
        while(!(I2C1->ISR & I2C_ISR_RXNE));
        *data++=I2C1->RXDR;
    }
    while(!(I2C1->ISR & I2C_ISR_STOPF));
    I2C1->ICR = I2C_ICR_STOPCF;
}
void MemsConfig(void)
{
  i2cInit();
  i2cWrite(ACC_I2C_ADDRESS, LSM303DLHC_CTRL_REG1_A,LSM303DLHC_NORMAL_MODE | LSM303DLHC_ODR_50_HZ | LSM303DLHC_AXES_ENABLE);
  i2cWrite(ACC_I2C_ADDRESS, LSM303DLHC_CTRL_REG4_A,LSM303DLHC_FULLSCALE_2G | LSM303DLHC_BlockUpdate_Continous | LSM303DLHC_BLE_LSB | LSM303DLHC_HR_ENABLE);
  i2cWrite(ACC_I2C_ADDRESS, LSM303DLHC_CTRL_REG2_A,LSM303DLHC_HPM_NORMAL_MODE | LSM303DLHC_HPFCF_16 | LSM303DLHC_HPF_AOI1_DISABLE | LSM303DLHC_HPF_AOI2_DISABLE);
 
  i2cWrite(MAG_I2C_ADDRESS, LSM303DLHC_CRA_REG_M, LSM303DLHC_TEMPSENSOR_ENABLE | LSM303DLHC_ODR_30_HZ);
  i2cWrite(MAG_I2C_ADDRESS, LSM303DLHC_CRB_REG_M, LSM303DLHC_FS_8_1_GA);
  i2cWrite(MAG_I2C_ADDRESS, LSM303DLHC_MR_REG_M,LSM303DLHC_CONTINUOS_CONVERSION);
}

void ReadAccelerometer(int16_t * data) {  
    i2cRead(ACC_I2C_ADDRESS, LSM303DLHC_OUT_X_L_A, (uint8_t *)data, 6);
}

void ReadMagnetometer(int16_t * data) {
    i2cRead(MAG_I2C_ADDRESS, LSM303DLHC_OUT_X_L_M, (uint8_t *)data, 1);
    i2cRead(MAG_I2C_ADDRESS, LSM303DLHC_OUT_X_H_M, (uint8_t *)data+1, 1);
    i2cRead(MAG_I2C_ADDRESS, LSM303DLHC_OUT_Y_L_M, (uint8_t *)data+2, 1);
    i2cRead(MAG_I2C_ADDRESS, LSM303DLHC_OUT_Y_H_M, (uint8_t *)data+3, 1);
    i2cRead(MAG_I2C_ADDRESS, LSM303DLHC_OUT_Z_L_M, (uint8_t *)data+4, 1);
    i2cRead(MAG_I2C_ADDRESS, LSM303DLHC_OUT_Z_H_M, (uint8_t *)data+5, 1);
}