IoT_Ubung3

main.c

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/i2c.h"
#include "sdkconfig.h"
#include <math.h>

#define I2C_MASTER_PORT I2C_NUM_0
#define I2C_MASTER_SDA_IO 21
#define I2C_MASTER_SCL_IO 22
#define I2C_MASTER_FREQ_HZ 400000

void i2c_init() {
    i2c_config_t conf = {
            .mode = I2C_MODE_MASTER,
            .sda_io_num = I2C_MASTER_SDA_IO,
            .sda_pullup_en = GPIO_PULLUP_ENABLE,
            .scl_io_num = I2C_MASTER_SCL_IO,
            .scl_pullup_en = GPIO_PULLUP_ENABLE,
            .master.clk_speed = I2C_MASTER_FREQ_HZ
    };

    i2c_param_config(I2C_MASTER_PORT, &conf);

    i2c_driver_install(I2C_MASTER_PORT, conf.mode, 0, 0, 0);
}

uint8_t i2c_register_read(i2c_port_t port_num, uint8_t dev_addr, uint8_t reg_addr) {
    uint8_t data;
    i2c_cmd_handle_t cmd;
    esp_err_t ret;

    reg_addr = (0b1000 << 4) | reg_addr;

    uint8_t dev_addr_w = (dev_addr << 1) | I2C_MASTER_WRITE;
    uint8_t dev_addr_r = (dev_addr << 1) | I2C_MASTER_READ;

    cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, dev_addr_w, 1);
    i2c_master_write_byte(cmd, reg_addr, 1);
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, dev_addr_r, 1);
    i2c_master_read_byte(cmd, &data, I2C_MASTER_NACK);
    i2c_master_stop(cmd);

    ret = i2c_master_cmd_begin(port_num, cmd, portMAX_DELAY);
    i2c_cmd_link_delete(cmd);
    if (ret != ESP_OK) {
        puts("Single byte read failed!");
        exit(EXIT_FAILURE);
    }

    return data;
}

esp_err_t i2c_register_write(i2c_port_t port_num, uint8_t dev_addr, uint8_t reg_addr, uint8_t data) {
    i2c_cmd_handle_t cmd;
    esp_err_t ret;
    uint8_t dev_addr_w = (dev_addr << 1) | I2C_MASTER_WRITE;

    reg_addr = (0b1000 << 4) | reg_addr;

    cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, dev_addr_w, 1);
    i2c_master_write_byte(cmd, reg_addr, 1);
    i2c_master_write_byte(cmd, data, 1);
    i2c_master_stop(cmd);
    ret = i2c_master_cmd_begin(port_num, cmd, portMAX_DELAY);
    i2c_cmd_link_delete(cmd);

    return ret;
}

esp_err_t i2c_multi_register_read(i2c_port_t port_num, uint8_t dev_addr, uint8_t reg_addr, uint8_t *data, size_t size) {
    i2c_cmd_handle_t cmd;
    esp_err_t ret;

    reg_addr = (0b1000 << 4) | reg_addr;

    uint8_t dev_addr_w = (dev_addr << 1) | I2C_MASTER_WRITE;
    uint8_t dev_addr_r = (dev_addr << 1) | I2C_MASTER_READ;

    cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, dev_addr_w, 1);
    i2c_master_write_byte(cmd, reg_addr, 1);
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, dev_addr_r, 1);
    i2c_master_read(cmd, data, size, I2C_MASTER_ACK);
    i2c_master_stop(cmd);

    ret = i2c_master_cmd_begin(port_num, cmd, portMAX_DELAY);
    i2c_cmd_link_delete(cmd);

    return ret;
}

void lux_sensor_init() {
    i2c_register_write(I2C_MASTER_PORT, 0x29, 0x0, 0x03);
    i2c_register_write(I2C_MASTER_PORT, 0x29, 0x1, 0b10010);
}

uint8_t lux_read_sensor_id() {
    return i2c_register_read(I2C_MASTER_PORT, 0x29, 0xA);
}

uint8_t lux_read_ctrl_reg() {
    return i2c_register_read(I2C_MASTER_PORT, 0x29, 0x0);
}

float lux_read_sensor_value() {
    uint8_t ch0[2];
    uint8_t ch1[2];

    float CH0;
    float CH1;
    float div;

    float lux = 0;

    i2c_multi_register_read(I2C_MASTER_PORT, 0x29, 0xC, ch0, 2);
    i2c_multi_register_read(I2C_MASTER_PORT, 0x29, 0xE, ch1, 2);

    CH0 = (float) ((ch0[1] << 8) | ch0[0]);
    CH1 = (float) ((ch1[1] << 8) | ch1[0]);

    div = CH1 / CH0;

    printf("CH0: %d, CH1: %d; DIV: %f\n", ch0[1] << 8 | ch0[0], ch1[1] << 8 | ch1[0], div);

    if (0 < div && div <= 0.5) {
        lux = (float) (0.0304 * CH0 - 0.062 * CH0 * pow(div, 1.4));
    } else if (0.5 < div && div <= 0.61) {
        lux = (float) (0.0224 * CH0 - 0.031 * CH1);
    } else if (0.61 < div && div <= 0.8) {
        lux = (float) (0.0128 * CH0 - 0.0153 * CH1);
    } else if (0.8 < div && div <= 1.3) {
        lux = (float) (0.00146 * CH0 - 0.00112 * CH1);
    } else if (div > 1.3) {
        lux = 0;
    }

    return lux;
}

_Noreturn void app_main() {
    i2c_init();
    lux_sensor_init();
    puts("Init success!");

    int delay_ticks = pdMS_TO_TICKS(400);
    vTaskDelay(delay_ticks);

    uint8_t id = lux_read_sensor_id();
    uint8_t ctrl = lux_read_ctrl_reg();

    printf("Sensor id: 0x%x, Control Register: 0x%x\n", id, ctrl & 0b11);

    while (true) {
        double ll = lux_read_sensor_value();
        printf("Light level: %f lux\n", ll);
        vTaskDelay(pdMS_TO_TICKS(1000));
    }

}