基于小熊派光强传感器BH1750状态机驱动项目升级(带LCD屏显示)

3、配置LCD_WR_RS、LCD_RESET、LCD_POWER

LIGHT_SENSOR_I2C\LIGHT_SENSOR_I2C.axf: Error: L6218E: Undefined symbol SPI2_WriteByte (referred from lcd.o).

找到这个错误的地方，添加一个这样的函数，再编译，解决问题。    

接下来在main.c中添加头文件：

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "lcd.h"
#include "HzLib.h"
/* USER CODE END Includes */

接下来添加LCD显示逻辑：

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
    /* USER CODE BEGIN 1 */
    char display_buf[20] = {0};
    /* USER CODE END 1 */

    /* MCU Configuration--------------------------------------------------------*/

    /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
    HAL_Init();

    /* USER CODE BEGIN Init */

    /* USER CODE END Init */

    /* Configure the system clock */
    SystemClock_Config();

    /* USER CODE BEGIN SysInit */

    /* USER CODE END SysInit */

    /* Initialize all configured peripherals */
    MX_GPIO_Init();
    MX_I2C1_Init();
    MX_USART1_UART_Init();
    MX_SPI2_Init();
    /* USER CODE BEGIN 2 */
    /*串口初始化后加这个延时，防止后面的printf打印乱码*/
    HAL_Delay(200);
    LCD_Init();
    LCD_Clear(BLACK);//清屏为黑色
    LCD_ShowString(5, 10, 240, 32, 32, "BearPi LuxTest");//显示字符串，字体大小32*32
    printf("光强读取测试实验\n");
    Init_BH750();
    timer_init(&lsensor.timer1, lsensor.timeout_cb, 1, 1);
    timer_start(&lsensor.timer1);
    /* USER CODE END 2 */

    /* Infinite loop */
    /* USER CODE BEGIN WHILE */
    while (1)
    {
        /* USER CODE END WHILE */

        /* USER CODE BEGIN 3 */
        ReadBH1750(LUX_1_MODE);

        if(1 == lsensor.Conver_completed)
        {
            sprintf(display_buf, "%d%d%d%dLux", lsensor.Lux / 1000 % 100, lsensor.Lux / 100 % 10, lsensor.Lux / 10 % 10, lsensor.Lux % 10);
            LCD_ShowString(80, 50 + 24 + 32, 240, 32, 32, display_buf); //显示字符串，字体大小32*32

            if(lsensor.Lux > LIGHT_SENSOR_THREHOLD)
            {
                HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);
            }
            else
            {
                HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_SET);
            }
        }

        timer_loop();

    }

    /* USER CODE END 3 */
}

这里这么来显示的主要原因是由于小熊派提供的例程里打印字符串不带清除功能，所以会有叠加效应，后面有时间解决，如果使用清除局部区域的函数，则会造成屏幕闪烁，体验感很不好。