BearPi Std 板从入门到放弃 - 筑基（1）(RT-Thread 智慧路灯)

news2024/9/29 1:15:47

简介

使用BearPi IOT Std开发板及其扩展板E53_SC1， SC1上有I2C1 的光照强度传感器BH1750 和 EEPROM  AT24C02， 智慧路灯功能, 实现亮度达到对应阈值则开启点灯
主板: 
	主芯片: STM32L431RCT6
	LED : PC13 \ 推挽输出\ 高电平点亮
	串口: Usart1
	I2C使用 : I2C1

E53_SC1扩展板 : 
	LED ： PB9 \ 推挽输出 \ 高电平点亮
	光照强度传感器：BH1750
	EEPROM芯片 : AT24C02
当 读取 BH1750 的值达到设定值, 打开LED灯, 低于设定值, 关闭LED灯

电路图原理图一览

扩展板 BH1750
在这里插入图片描述
扩展板 LED

步骤

创建工程, 初始化I2C, 添加I2C1设备到RT-Thread系统中
参考 BearPi Std 板从入门到放弃 - 先天神魂篇（3）(RT-Thread I2C设备)
添加用户代码
a. LED灯设定代码

#define SMART_SL_LED_PIN GET_PIN(B, 9)

typedef enum
{
	OFF,
	ON
}Smart_Streetlights_Status;


void Smart_Sl_LED_Set(Smart_Streetlights_Status status)
{
	rt_pin_write(SMART_SL_LED_PIN, status == OFF ? PIN_LOW : PIN_HIGH);
}

b. BH1750 功能代码

rt_err_t smart_sl_bh1750_init(void)
{
	uint8_t cmd = 0x11; // 连续读H分辨率模式2
	if (RT_NULL == i2c_bus)
	{
		i2c_bus = (struct rt_i2c_bus_device *)rt_device_find(SMART_SL_I2C_NAME); // 获取注册i2c1设备
	}
	
	if (RT_NULL == i2c_bus)
	{
		rt_kprintf("[smart_sl_led_set] get i2c1 device failed!\n");
		return -RT_ERROR;
	}
	
	if (1 != rt_i2c_master_send(i2c_bus, SMART_SL_BH1750_ADDR, RT_I2C_WR, &cmd, 1)) // 发送指令, 开启连续读模式
	{
		rt_kprintf("[smart_sl_led_set] send command failed!\n");
		return -RT_ERROR;
	}
	rt_thread_mdelay(180); // 写指令后最长读取等待时间180ms
	return RT_EOK;
}

rt_err_t smart_sl_bh1750_read(float *pLux)
{
	uint8_t temp[2];
	rt_uint8_t recvLength = sizeof(temp)/sizeof(uint8_t);
	
	if (recvLength != rt_i2c_master_recv(i2c_bus, 0x23, RT_I2C_RD, temp, recvLength))
	{
		return -RT_ERROR;
	}
	
	/* 计算光照强度数据 */
	*pLux = (float)((temp[0]<<8)|temp[1]);
	*pLux /= (float)(1.2);
	
	return RT_EOK;
}

c. 初始化和线程创建部分

rt_err_t smart_sl_init(void)
{
	rt_pin_mode(SMART_SL_LED_PIN, PIN_MODE_OUTPUT);
	if (RT_EOK == smart_sl_bh1750_init())
	{
		initialized = 1;
		return RT_EOK;
	}
	return -RT_ERROR;
}


static void smart_sl_entry(void *parameter)
{
	float lux = 0.0;
	uint16_t fCnt = 0; // 错误次数, 不可原谅次数
	uint16_t fMaxTime = 10;
	Smart_Streetlights_Status status = OFF;
	if (!initialized)
	{
		if (RT_EOK  != smart_sl_init())
		{
			rt_kprintf("fail to init smart streetlights!\n");
			return;
		}
	}
	
	smart_sl_led_set(OFF); 
	while (1)
	{
		rt_thread_mdelay(500); // 500ms 遍历一次
		if (RT_EOK != smart_sl_bh1750_read(&lux))
		{
			fCnt += 1;
			if (fCnt >= fMaxTime)
			{
				rt_kprintf("The BH1750 has read an error more than %d times!\n", fMaxTime);
				fCnt -= 1;
			}
			continue;
		}
		
		if (lux > luminosity_threshold)
		{
			if (status == OFF)
				continue;
			status = OFF;
		}
		else
		{
			if (status == ON)
				continue;
			status = ON;
		}
		smart_sl_led_set(status); 
		rt_kprintf("The current light intensity is %flx, and the LED light is turned %s.\n", lux, status == ON ? "on" : "off");
	}
}

static int smart_sl(int argc, char *argv[])
{
	 rt_thread_t tid;
	 rt_err_t ret = RT_EOK;
	 tid = rt_thread_create("smart_sl",
												smart_sl_entry,
												RT_NULL,
												512,
												RT_THREAD_PRIORITY_MAX / 3,
												20);
	 if (tid != RT_NULL)
	 {
			rt_thread_startup(tid);
	 }
	 else
	 {
			ret = RT_ERROR;
	 }
	 return ret;
}

/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(smart_sl, led sample);