nRF52832的I2C例程代码

nRF52832的I2C例程代码

#include "nrf_drv_i2c.h"
#include "app_error.h"

#define I2C_SCL_PIN     0   // SCL引脚号
#define I2C_SDA_PIN     1   // SDA引脚号
#define MAX_PENDING_TRANSACTIONS    5   // 最大等待事务数

static const nrf_drv_i2c_t i2c = NRF_DRV_I2C_INSTANCE(0);   // I2C实例号

static uint8_t m_sample[4];   // 读取数据缓冲区

// 完成事件处理函数
void i2c_event_handler(nrf_drv_i2c_evt_t const * p_event, void * p_context)
{
    switch (p_event->type)
    {
        case NRF_DRV_I2C_EVT_DONE:
            if (p_event->xfer_desc.type == NRF_DRV_I2C_XFER_RX)
            {
                // 读取完成，执行对应操作
            }
            break;
        default:
            break;
    }
}

// 初始化I2C 
void i2c_init(void)
{
    ret_code_t err_code;

    nrf_drv_i2c_config_t config = NRF_DRV_I2C_DEFAULT_CONFIG;
    config.scl = I2C_SCL_PIN;
    config.sda = I2C_SDA_PIN;

    err_code = nrf_drv_i2c_init(&i2c, &config, i2c_event_handler, NULL);
    APP_ERROR_CHECK(err_code);

    nrf_drv_i2c_enable(&i2c);
}

// 读取数据示例
void i2c_read_data(uint8_t address, uint8_t reg, uint8_t * data, uint8_t len)
{
    ret_code_t err_code;

    nrf_drv_i2c_xfer_desc_t xfer_desc;
    xfer_desc.address = address;
    xfer_desc.type = NRF_DRV_I2C_XFER_TXRX;
    xfer_desc.primary_length = 1;
    xfer_desc.secondary_length = len - 1;
    xfer_desc.p_primary_buf = ®
    xfer_desc.p_secondary = data;

    err_code = nrf_drv_i2c_schedule(&i2c, &xfer_desc, MAX_PENDING_TRANSACTIONS);
    APP_ERROR_CHECK(err_code);
}

// 写入数据示例
void i2c_write_data(uint8_t address, uint8_t reg, uint8_t * data, uint8_t len)
{
    ret_code_t err_code;

    uint8_t buffer[20];
    buffer[0] = reg;
    memcpy(&buffer[1], data, len);

    nrf_drv_i2c_xfer_desc_t xfer_desc;
    xfer_desc.address = address;
    xfer_desc.type = NRF_DRV_I2C_XFER_TX;
    xfer_desc.primary_length = len + 1;
    xfer_desc.p_primary_buf = buffer;

    err_code = nrf_drv_i2c_schedule(&i2c, &xfer_desc, MAX_PENDING_TRANSACTIONS);
    APP_ERROR_CHECK(err_code);
}

这个例程中，i2c_init()函数用于初始化I2C，并设置了SCL和SD引脚号。i2c_read_data()函数用于读取数据，i2c_write_data()函数用于写入数据。在读取完成后会调用i2c_event_handler()进行处理。