1.0 BMP180
此图转载钦源盛数码专营店
本篇通过Renesas RA6M4开发板采用I2C读取BMP180传感器的气压温度示例程序演示。
1.1 BMP180介绍
1、BMP180是一款高精度、小体积、低能耗的压力传感器，可以应用在移动设备中；
2、精度低，可以达到0.03hPa；
3、BMP180采用强大的8-pin陶瓷无引线芯片承载(LCC)超薄封装，可以通过I2C总线直接与各种微处理器相连。
1.2 BMP180特点
1.压力范围:300—1100hPa(海拔9000米一500米)
2.电源电压:5V
3.低功耗:在标准模式下5uA
4.高精度:低功耗模式下，分辨率为0.06hPa(0.5米)
5.高线性模式下，分辨率为0.03hPa(0.25米)
6.带温度输出
7.I2C通信方式8.带温度补偿
9.MSL1秒响应
10.待机电流:0.1uA
11.需在气体环境中工作，不可测量液体和反接电源😅😅😅
尺寸大小如下：
1.3 产品应用
1.GPS导航(航位推算，上下桥检测等)
⒉.室内室外导航
3.休闲、体育等监测
4.天气预报
5.垂直速度指示(上升/下沉速度)
2. RT-theard配置
2.1 硬件需求
1、需要BMP180采集气体环境下的气压和温度，I2C通讯接线SDA—p503;SCL—p504，不需要关注地址后面库自带配置了，与ssd1306不同
实现功能：
I2C读取BMP180传感器的气压温度
2、RA6M4开发板
3、USB下载线，ch340串口和附带6根母母线，rx—p613;tx—p614
2.2 软件配置
Renesas RA6M4开发板环境配置参照：【基于 RT-Thread Studio的CPK-RA6M4 开发板环境搭建】
1、新建项目RA6M4-bmp180工程
2、点击RT-theard Setting，在软件包下添加软件包，然后搜索bmp相关软件支持包，点击添加即可,然后出现对应包。
3、配置ssd306，右键选择配置项
4、在软件包中开启示例程序。
5、在硬件中，启动I2C，设置端口SDA—p503;SCL—p504
6、全部保存刚刚的配置，更新当前配置文件
保存完是灰色，没有保存是蓝色。
3. 代码分析
1、刚刚加载软件包在packages文件夹下，bmp180.c和bmp180_sample.c示例代码更改为如下
（或者头文件添加#include "bsp_api.h",否则会报错unitx_t，根据提示全部改为rt_unitx_t也OK，下面是第二种方法）😅😅😅
bmp180.c
/* * Copyright (c) 2020 panrui <https://github.com/Prry/rtt-bmp180> * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2020-03-12 panrui the first version */ #include <rtthread.h> #include <rtdevice.h> #include <rtdbg.h> #include "sensor.h" #include "bmp180.h" #define PKG_USING_BMP180 #ifdef PKG_USING_BMP180 #define BMP180_ADDR 0x77 /* i2c slave address */ #define BMP_REG_CHIP_ID 0xD0 #define BMP_REG_RESET 0xE0 #define BMP_REG_CTRL_ADDR 0xF4 #define BMP_REG_AD_MSB 0xF6 #define BMP_REG_AD_LSB 0xF7 #define BMP_REG_AD_XLSB 0xF8 #define BMS_CAL_AC1 0xAA #define BMP_REG_CTRL_TEMP 0x2E #define BMP_REG_CTRL_POSS0 0x34 #define BMP_REG_CTRL_POSS1 0x74 #define BMP_REG_CTRL_POSS2 0xB4 #define BMP_REG_CTRL_POSS3 0xF4 #define BMP_REG_RESET_VALUE 0xB6 #define BMP180_I2C_BUS "i2c1" /* i2c linked */ #define BMP180_DEVICE_NAME "bmp180" /* register device name */ /* bmp clalc param */ struct bmp180_calc { short ac1; short ac2; short ac3; short b1; short b2; short mb; short mc; short md; unsigned short ac4; unsigned short ac5; unsigned short ac6; }; /* bmp180 private data */ struct bmp180_dev { struct bmp180_calc calc_param; struct rt_i2c_bus_device *i2c_bus; /* linked i2c bus */ }; static rt_err_t bmp180_read_regs(rt_sensor_t psensor, rt_uint8_t reg, rt_uint8_t *data, rt_uint8_t data_size) { struct rt_i2c_msg msg[2]; struct bmp180_dev *dev = RT_NULL; struct rt_i2c_bus_device *i2c_bus = RT_NULL; rt_uint32_t slave_addr = 0; slave_addr = (rt_uint32_t)psensor->config.intf.user_data; /* get i2c slave address */ dev = (struct bmp180_dev*)psensor->parent.user_data;/* bmp180 private data */ i2c_bus = (struct rt_i2c_bus_device*)dev->i2c_bus; /* get i2c bus device */ msg[0].addr = (rt_uint8_t)slave_addr; msg[0].flags = RT_I2C_WR; msg[0].len = 1; msg[0].buf = ® msg[1].addr = (rt_uint8_t)slave_addr; msg[1].flags = RT_I2C_RD; msg[1].len = data_size; msg[1].buf = data; if(rt_i2c_transfer(i2c_bus, msg, 2) == 2) { return RT_EOK; } else { LOG_E("i2c bus read failed!\r\n"); return -RT_ERROR; } } static rt_err_t bmp180_write_regs(rt_sensor_t psensor, rt_uint8_t reg, rt_uint8_t *data, rt_uint8_t data_size) { struct rt_i2c_msg msg[2]; struct bmp180_dev *dev = RT_NULL; struct rt_i2c_bus_device *i2c_bus; rt_uint32_t slave_addr = 0; slave_addr = (rt_uint32_t)psensor->config.intf.user_data; dev = (struct bmp180_dev*)psensor->parent.user_data; i2c_bus = (struct rt_i2c_bus_device*)dev->i2c_bus; msg[0].addr = (rt_uint8_t)slave_addr; msg[0].flags = RT_I2C_WR; msg[0].len = 1; msg[0].buf = ® msg[1].addr = (rt_uint8_t)slave_addr; msg[1].flags = RT_I2C_WR | RT_I2C_NO_START; msg[1].len = data_size; msg[1].buf = data; if(rt_i2c_transfer(i2c_bus, msg, 2) == 2) { return RT_EOK; } else { LOG_E("i2c bus write failed!\r\n"); return -RT_ERROR; } } static rt_err_t bmp180_write_reg(rt_sensor_t psensor, rt_uint8_t reg, rt_uint8_t data) { return bmp180_write_regs(psensor, reg, &data, 1); } static long bmp180_read_ut(rt_sensor_t psensor) { rt_uint8_t buf[2] = {0}; long data = 0; bmp180_write_reg(psensor, BMP_REG_CTRL_ADDR, BMP_REG_CTRL_TEMP); rt_thread_delay(1); /* max conversion time: 4.5ms */ bmp180_read_regs(psensor, BMP_REG_AD_MSB, buf, 2); data = (buf[0]<<8) | buf[1]; return data; } static long bmp180_read_up(rt_sensor_t psensor) { rt_uint8_t buf[2] = {0}; long data = 0; bmp180_write_reg(psensor, BMP_REG_CTRL_ADDR, BMP_REG_CTRL_POSS0); rt_thread_delay(1); /* max conversion time: 4.5ms */ bmp180_read_regs(psensor, BMP_REG_AD_MSB, buf, 2); data = (buf[0]<<8) | buf[1]; return data; } static rt_size_t bmp180_polling_get_data(rt_sensor_t psensor, struct rt_sensor_data *sensor_data) { long x1, x2, b5, b6, x3, b3, p; unsigned long b4, b7; short temperature=0; long ut,up,pressure=0; struct bmp180_dev *dev = RT_NULL; struct bmp180_calc *param = RT_NULL; ut = bmp180_read_ut(psensor); up = bmp180_read_up(psensor); dev = (struct bmp180_dev*)psensor->parent.user_data;/* bmp180 private data */ param = &dev->calc_param; /* get calc param */ /* temperature calc */ x1 = (((long)ut - (long)param->ac6)*(long)param->ac5) >> 15; x2 = ((long)param->mc << 11) / (x1 + param->md); b5 = x1 + x2; temperature = ((b5 + 8) >> 4); /* pressure calc */ b6 = b5 - 4000; x1 = (param->b2 * (b6 * b6)>>12)>>11; x2 = (param->ac2 * b6)>>11; x3 = x1 + x2; b3 = (((((long)param->ac1)*4 + x3)<<0) + 2)>>2; x1 = (param->ac3 * b6)>>13; x2 = (param->b1 * ((b6 * b6)>>12))>>16; x3 = ((x1 + x2) + 2)>>2; b4 = (param->ac4 * (unsigned long)(x3 + 32768))>>15; b7 = ((unsigned long)(up - b3) * (50000>>0)); if (b7 < 0x80000000) { p = (b7<<1)/b4; } else { p = (b7/b4)<<1; } x1 = (p>>8) * (p>>8); x1 = (x1 * 3038)>>16; x2 = (-7357 * p)>>16; pressure = p+((x1 + x2 + 3791)>>4); if(psensor->info.type == RT_SENSOR_CLASS_BARO) {/* actual barometric */ sensor_data->type = RT_SENSOR_CLASS_BARO; sensor_data->data.baro = pressure; sensor_data->timestamp = rt_sensor_get_ts(); } else if(psensor->info.type == RT_SENSOR_CLASS_TEMP) {/* actual temperature */ sensor_data->type = RT_SENSOR_CLASS_TEMP; sensor_data->data.temp = temperature; sensor_data->timestamp = rt_sensor_get_ts(); } else { return 0; } return 1; } static rt_size_t bmp180_fetch_data(struct rt_sensor_device *psensor, void *buf, rt_size_t len) { RT_ASSERT(buf); RT_ASSERT(psensor); //if(psensor->parent.open_flag & RT_DEVICE_FLAG_RDONLY) if(psensor->config.mode == RT_SENSOR_MODE_POLLING) { return bmp180_polling_get_data(psensor, buf); } return 0; } static rt_err_t bmp180_control(struct rt_sensor_device *psensor, int cmd, void *args) { rt_err_t ret = RT_EOK; rt_uint8_t *chip_id; RT_ASSERT(psensor); switch (cmd) { /* read bmp180 id */ case RT_SENSOR_CTRL_GET_ID: chip_id = (rt_uint8_t*)args; ret = bmp180_read_regs(psensor, BMP_REG_CHIP_ID, chip_id, 1); break; default: break; } return ret; } static struct rt_sensor_ops bmp180_ops = { bmp180_fetch_data, bmp180_control, }; int rt_hw_bmp180_init(const char *name, struct rt_sensor_config *cfg) { rt_err_t ret = RT_EOK; rt_sensor_t sensor_baro = RT_NULL, sensor_temp = RT_NULL; struct rt_sensor_module *module = RT_NULL; struct bmp180_dev *bmp180 = RT_NULL; rt_uint8_t bmbuf[22] = {0}; bmp180 = rt_calloc(1, sizeof(struct bmp180_dev)); if(bmp180 == RT_NULL) { LOG_E("malloc memory failed\r\n"); ret = -RT_ERROR; goto __exit; } bmp180->i2c_bus = rt_i2c_bus_device_find(cfg->intf.dev_name); if(bmp180->i2c_bus == RT_NULL) { LOG_E("i2c bus device %s not found!\r\n", cfg->intf.dev_name); ret = -RT_ERROR; goto __exit; } module = rt_calloc(1, sizeof(struct rt_sensor_device)); if(module == RT_NULL) { LOG_E("malloc memory failed\r\n"); ret = -RT_ERROR; goto __exit; } module->sen[0] = sensor_baro; module->sen[1] = sensor_temp; module->sen_num = 2; /* barometric pressure sensor register */ { sensor_baro = rt_calloc(1, sizeof(struct rt_sensor_device)); if (sensor_baro == RT_NULL) { goto __exit; } rt_memset(sensor_baro, 0x0, sizeof(struct rt_sensor_device)); sensor_baro->info.type = RT_SENSOR_CLASS_BARO; sensor_baro->info.vendor = RT_SENSOR_VENDOR_BOSCH; sensor_baro->info.model = "bmp180_baro"; sensor_baro->info.unit = RT_SENSOR_UNIT_PA; sensor_baro->info.intf_type = RT_SENSOR_INTF_I2C; sensor_baro->info.range_max = 110000; /* 1Pa */ sensor_baro->info.range_min = 30000; sensor_baro->info.period_min = 100; /* read ten times in 1 second */ rt_memcpy(&sensor_baro->config, cfg, sizeof(struct rt_sensor_config)); sensor_baro->ops = &bmp180_ops; sensor_baro->module = module; ret = rt_hw_sensor_register(sensor_baro, name, RT_DEVICE_FLAG_RDWR, (void*)bmp180); if (ret != RT_EOK) { LOG_E("device register err code: %d", ret); goto __exit; } } /* temperature sensor register */ { sensor_temp = rt_calloc(1, sizeof(struct rt_sensor_device)); if (sensor_temp == RT_NULL) { goto __exit; } rt_memset(sensor_temp, 0x0, sizeof(struct rt_sensor_device)); sensor_temp->info.type = RT_SENSOR_CLASS_TEMP; sensor_temp->info.vendor = RT_SENSOR_VENDOR_BOSCH; sensor_temp->info.model = "bmp180_temp"; sensor_temp->info.unit = RT_SENSOR_UNIT_DCELSIUS; sensor_temp->info.intf_type = RT_SENSOR_INTF_I2C; sensor_baro->info.range_max = 850; /* 0.1C */ sensor_baro->info.range_min = -400; sensor_temp->info.period_min = 100; /* read ten times in 1 second */ rt_memcpy(&sensor_temp->config, cfg, sizeof(struct rt_sensor_config)); sensor_temp->ops = &bmp180_ops; sensor_temp->module = module; ret = rt_hw_sensor_register(sensor_temp, name, RT_DEVICE_FLAG_RDWR, (void*)bmp180); if (ret != RT_EOK) { LOG_E("device register err code: %d", ret); goto __exit; } } /* bmp180 read calc param */ ret = bmp180_read_regs(sensor_baro, BMS_CAL_AC1, bmbuf, 22); if(ret == RT_EOK) { bmp180->calc_param.ac1 = (bmbuf[0]<<8)|bmbuf[1]; bmp180->calc_param.ac2 = (bmbuf[2]<<8)|bmbuf[3]; bmp180->calc_param.ac3 = (bmbuf[4]<<8)|bmbuf[5]; bmp180->calc_param.ac4 = (bmbuf[6]<<8)|bmbuf[7]; bmp180->calc_param.ac5 = (bmbuf[8]<<8)|bmbuf[9]; bmp180->calc_param.ac6 = (bmbuf[10]<<8)|bmbuf[11]; bmp180->calc_param.b1 = (bmbuf[12]<<8)|bmbuf[13]; bmp180->calc_param.b2 = (bmbuf[14]<<8)|bmbuf[15]; bmp180->calc_param.mb = (bmbuf[16]<<8)|bmbuf[17]; bmp180->calc_param.mc = (bmbuf[18]<<8)|bmbuf[19]; bmp180->calc_param.md = (bmbuf[20]<<8)|bmbuf[21]; } else { LOG_E("bmp180 read calc param failed\r\n"); goto __exit; } return RT_EOK; __exit: if(sensor_baro) { rt_free(sensor_baro); } if(sensor_temp) { rt_free(sensor_temp); } if(module) { rt_free(module); } if (bmp180) { rt_free(bmp180); } return ret; } #endif /* PKG_USING_BMP180 */
bmp180_sample.c
/* * Copyright (c) 2020 panrui <https://github.com/Prry/rtt-bmp180> * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2020-03-12 panrui the first version */ #include <rtthread.h> #include <rtdevice.h> #include "sensor.h" #include "bmp180.h" static void read_baro_entry(void *parameter) { rt_device_t baro_dev = RT_NULL, temp_dev = RT_NULL; struct rt_sensor_data baro_data,temp_data; rt_size_t res0 = 0, res1 = 1; rt_uint8_t chip_id; baro_dev = rt_device_find("baro_bmp180"); if (baro_dev == RT_NULL) { rt_kprintf("not found baro_bmp180 device\r\n"); return; } if (rt_device_open(baro_dev, RT_DEVICE_FLAG_RDONLY) != RT_EOK) { rt_kprintf("open baro_180 failed\r\n"); return; } temp_dev = rt_device_find("temp_bmp180"); if (temp_dev == RT_NULL) { rt_kprintf("not found temp_bmp180 device\r\n"); return; } if (rt_device_open(temp_dev, RT_DEVICE_FLAG_RDONLY) != RT_EOK) { rt_kprintf("open temp_bmp180 failed\r\n"); return; } rt_device_control(baro_dev, RT_SENSOR_CTRL_SET_ODR, (void *)(1));/* 1Hz read */ rt_device_control(temp_dev, RT_SENSOR_CTRL_SET_ODR, (void *)(1));/* 1Hz read */ rt_device_control(temp_dev, RT_SENSOR_CTRL_GET_ID, (void*)&chip_id); rt_kprintf("bmp180 chip ID [0x%X]\n", chip_id); while (1) { res0 = rt_device_read(baro_dev, 0, &baro_data, 1); res0 = rt_device_read(temp_dev, 0, &temp_data, 1); if (res0==0 || res1==0) { rt_kprintf("read data failed! result is %d,%d\n", res0, res1); rt_device_close(baro_dev); rt_device_close(temp_dev); return; } else { rt_kprintf("baro[%dPa],temp[%d.%dC],timestamp[%d]\r\n", baro_data.data.baro, temp_data.data.temp/10-42, temp_data.data.temp%10, temp_data.timestamp); } rt_thread_delay(500); } } static int baro_read_sample(void) { rt_thread_t baro_thread; baro_thread = rt_thread_create("baro_r", read_baro_entry, RT_NULL, 1024, RT_THREAD_PRIORITY_MAX / 2, 20); if (baro_thread != RT_NULL) { rt_thread_startup(baro_thread); } return RT_EOK; } INIT_APP_EXPORT(baro_read_sample); static int rt_hw_bmp180_port(void) { struct rt_sensor_config cfg; cfg.intf.dev_name = "i2c1"; /* i2c bus */ cfg.intf.user_data = (void *)0x77; /* i2c slave addr */ rt_hw_bmp180_init("bmp180", &cfg); /* bmp180 */ return RT_EOK; } INIT_COMPONENT_EXPORT(rt_hw_bmp180_port);
2、此库包含读取I2C信息，解调，并且添加一个进程、每秒自动打印温度和气压以及时间。
关键打印代码以及自行校准两项参数
rt_kprintf("baro[%dPa],temp[%d.%dC],timestamp[%d]\r\n", baro_data.data.baro, temp_data.data.temp/10-42, temp_data.data.temp%10, temp_data.timestamp);
3、main.c文件在re_gen文件夹下，主程序围绕“hal_entry();”函数（在src文件夹），这些默认不变
/
4. 下载验证
1、编译重构
编译成功
2、下载程序
下载成功
3、CMD串口调试
然后板载复位，开始串口打印显示！🎉🎉🎉
效果如下
