i2c.c

Explains how to send values to the 7-digit module over I2C.

/*
 * This example shows how to write to the 7-digit module over I2C.
 */

#include <stm32f4xx.h>
#include <carme.h>
#include <i2c.h>

#define SAA1064_SUBADDR_0   0x00        /* instructions byte for the SAA1064*/

#define SAA1064_ADD_12mA    (1<<6)      /* +12mA Digitalstrom               */
#define SAA1064_ADD_9mA     (11<<4)     /* +9mA Digitalstrom                */
#define SAA1064_ADD_6mA     (1<<5)      /* +6mA Digitalstrom                */
#define SAA1064_ADD_3mA     (1<<4)      /* +3mA Digitalstrom                */
#define SAA1064_SEGTEST     (1<<3)      /* Alle Segmente an                 */
#define SAA1064_ENA24       (1<<2)      /* Segmente 2,4 an                  */
#define SAA1064_ENA13       (1<<1)      /* Segmente 1,3 an                  */
#define SAA1064_DYNMODE     (1<<0)      /* Dynic Mode (multiplexed)         */

/*
 * hex to seven digit values
 */
uint8_t hex2sevenSeg[] = {
        0x3F /* 0 */, 0x06 /* 1 */, 0x5B /* 2 */, 0x4F /* 3 */,
        0x66 /* 4 */, 0x6D /* 5 */, 0x7D /* 6 */, 0x07 /* 7 */,
        0x7F /* 8 */, 0x6F /* 9 */, 0x77 /* A */, 0x7C /* b */,
        0x39 /* C */, 0x5E /* d */, 0x79 /* E */, 0x71 /* F */,
};

static __IO uint32_t TimingDelay;

/*
 * make a delay with the frequency of the systick
 */
void Delay(__IO uint32_t nTime) {
    TimingDelay = nTime;
    while (TimingDelay != 0);
}

void SysTick_Handler(void) {
    if (TimingDelay) {
        TimingDelay--;
    }
}

int main(void) {

    uint16_t count = 0;
    uint8_t i2c_value[5];

    /* initialize systick with 1 kHz */
    if (SysTick_Config(SystemCoreClock / 1000)) {
        while (1);
    }

    /* initialize the I2C bus */
    CARME_I2C_Init(CARME_I2C_BOARD);

    /* initialize the seven digit module */
    i2c_value[0] = SAA1064_ADD_12mA | SAA1064_ENA24 | SAA1064_ENA13 | SAA1064_DYNMODE;
    i2c_value[1] = 0;
    i2c_value[2] = 0;
    i2c_value[3] = 0;
    i2c_value[4] = 0;
    CARME_I2C_Write(CARME_I2C_BOARD, 0x70, SAA1064_SUBADDR_0, 0, i2c_value, sizeof(i2c_value));

    for (;;) {
        /* convert hex to seven digit values */
        i2c_value[1] = hex2sevenSeg[(count % 0x10000) / 0x1000];
        i2c_value[2] = hex2sevenSeg[(count % 0x1000) / 0x100];
        i2c_value[3] = hex2sevenSeg[(count % 0x100) / 0x10];
        i2c_value[4] = hex2sevenSeg[(count % 0x10) / 0x1];
        /* send values to seven digit module */
        CARME_I2C_Write(CARME_I2C_BOARD, 0x70, SAA1064_SUBADDR_0, 0, i2c_value, sizeof(i2c_value));
        count++;
        Delay(250);
    }
    return 0;
}