xc_ppf1901/drivers/max6884.c

#include <stdio.h>
#include "max6884.h"
#include "dwt.h"
#include "gpio.h"
#include "cmd.h"

#define ADDR  0x52

static i2c_t _i2c;

int i2c6884_read(uint8_t slv_addr, uint8_t reg,  signed char *buf, uint32_t count)
{
    i2c_start(_i2c);

    i2c_send_byte(_i2c, (slv_addr << 1));
    if(i2c_wait_ack(_i2c))
    {
        i2c_stop(_i2c);
        printf("address no ack\r\n");
        return -1;
    }
    i2c_send_byte(_i2c, reg);
    if(i2c_wait_ack(_i2c))
    {
        i2c_stop(_i2c);
        return -1;
    }

    i2c_start(_i2c);

    i2c_send_byte(_i2c,(slv_addr << 1) | 0x1);
    if(i2c_wait_ack(_i2c))
    {
        i2c_stop(_i2c);
        return -1;
    }

    for(int i=0; i<count; i++)
    {
        buf[i] = i2c_recv_byte(_i2c);
        if(i == (count - 1))
            i2c_nack(_i2c);
        else 
            i2c_ack(_i2c);
    }
    i2c_stop(_i2c);
    return count;
}

int i2c6884_write(uint8_t slv_addr, uint8_t reg, uint8_t data, uint32_t count)
{
    //int i;

    i2c_start(_i2c);

    i2c_send_byte(_i2c, (slv_addr << 1));

    if(i2c_wait_ack(_i2c)) {
        i2c_stop(_i2c);
        //printf("address no ack\r\n");
        return -1;
    }
#if 1
    i2c_send_byte(_i2c,reg);
    if(i2c_wait_ack(_i2c)) {
        //printf("31730 reg first byte no ack   reg = %x\r\n",reg);
        i2c_stop(_i2c);
        return -1;
    } 

    i2c_send_byte(_i2c,data);
    if(i2c_wait_ack(_i2c)) {
        //printf("31730 data first byte no ack    reg = %x\r\n",reg);
        i2c_stop(_i2c);
        return -1;
    }


#else
    i2c_send_byte(_i2c,reg);
    if(i2c_wait_ack(_i2c)) {
        //printf("first byte no ack\r\n");
        i2c_stop(_i2c);
        return -1;
    }

#endif

    i2c_stop(_i2c);
    return count;
}


void max6884_init(i2c_t i2c)
{   
    _i2c = i2c;
    gpio_init(PH4, GPIO_OUTPUT);
    gpio_clear(PH4);
    dwt_wait_ms(10);
    gpio_set(PH4);
    
    gpio_init(PH3, GPIO_INPUT); //WDOn
    gpio_init(PH6, GPIO_OUTPUT); //WDIn

    i2c6884_write(ADDR,0x96,0x00, 1);
    dwt_wait_ms(10);
    i2c6884_write(ADDR,0x8f,0x3B, 1);
}

static signed char  max6884_read(uint8_t reg)
{
    signed char  buf;
    i2c6884_read(ADDR, reg, &buf, 1);
    return buf;
}

static int max6884_write(uint8_t reg, uint8_t data, int count)
{
    i2c6884_write(ADDR, reg, data, count);
    return 0;
}

float max6884_read_vol(uint8_t device_num)
{
    uint8_t V_MSB = 0x00, V_LSB = 0x00;
    signed char data_M, data_L;
    uint16_t data = 0;
    float vol = 0;
    
        switch(device_num)
    {
        case 1:
            V_MSB = 0x18;
            V_LSB = 0x19;
            break;
        case 2:
            V_MSB = 0x1A;
            V_LSB = 0x1B;
            break;
        case 3:
            V_MSB = 0x1C;
            V_LSB = 0x1D;
            break;
        case 4:
            V_MSB = 0x1E;
            V_LSB = 0x1F;
            break;
        case 5:
            V_MSB = 0x20;
            V_LSB = 0x21;
            break;
        case 6:
            V_MSB = 0x22;
            V_LSB = 0x23;
            break;
        default:
            break;
    }
    data_M = max6884_read(V_MSB);
    data_L = max6884_read(V_LSB);
    data = ((data | data_M) << 2) | (data_L & 0x03);
    if(device_num == 3)
        vol = data * 0.00732;
    else
        vol = data * 0.0036;
    return vol;
}