转发：ARM®mbed OS入门开发（五A）通过SPI与BMP280通信(mbed应用)

anywill · 发表于 2016-10-10 09:02:20

通过SPI与BMP280通信(mbed应用)2016-10-05 Summerain

根据管脚配置，将STM32和BMP280相连：

为了更好的理解，我直接使用了官方的C语言写的驱动文件，当然也可以参照官方驱动，用C++编写专门适用于mbed的驱动。同时，为了支持C语言编译或者说混合编译，需要在驱动头文件bmp280.h中添加几句话：

#ifdef _cplusplus
extern "C"{
#endif
... ...

#ifdef _cplusplus
}
#endif

下面是我的主函数main.cpp的代码：

#include "mbed.h"
#include "bmp280.h"
/************** SPI control mask******/
#define SPI_READ 0x80
#define SPI_WRITE 0x7F
/********************SPI function declarations***********************/

//SPI master连接到SPI通信引脚

SPI spi_bmp(SPI_MOSI, SPI_MISO, SPI_SCK);

DigitalOut CS(SPI_CS);

s8 BMP280_SPI_bus_write(u8 dev_addr, u8 reg_addr, u8 *reg_data, u8 cnt);
s8 BMP280_SPI_bus_read(u8 dev_addr, u8 reg_addr, u8 *reg_data, u8 cnt);
/********************End of SPI function declarations***********************/
void  Bus_routine(void);
void  BMP280_delay_msek(u32 msek);
struct bmp280_t bmp280;
Serial pc_my(SERIAL_TX, SERIAL_RX);
void Bus_routine(void) {
bmp280.bus_write = BMP280_SPI_bus_write;
bmp280.bus_read = BMP280_SPI_bus_read;
bmp280.delay_msec = BMP280_delay_msek;
}
/*  Brief : The delay routine
*  \param : delay in ms */
void  BMP280_delay_msek(u32 msek)
{
/*Here you can write your own delay routine*/
}
s8  BMP280_SPI_bus_read(u8 dev_addr, u8 reg_addr, u8 *reg_data, u8 cnt)
{
int iError = BMP280_INIT_VALUE;
CS=0;
iError =spi_bmp.write(reg_addr | SPI_READ);
for (u8 i = 0; i < cnt; i++)
      {
         reg_data = spi_bmp.write(0x00);
      }
CS=1;
return (s8)iError;
}
s8  BMP280_SPI_bus_write(u8 dev_addr, u8 reg_addr, u8 *reg_data, u8 cnt)
{
int iError = BMP280_INIT_VALUE;
CS=0;
u8 *array = ®_addr;
for(u8 i = 0; i < cnt; i++) {
   iError +=spi_bmp.write(array & SPI_WRITE);
      spi_bmp.write(reg_data);
}
CS=1;
return (s8)iError;
}
int main()
{
//首先初始化数据
/* Assign the standby time*/
u8 v_standby_time_u8 = BMP280_INIT_VALUE;
/* For Individual data read APIs*/
/* read uncompensated temperature*/
   s32 v_data_uncomp_tem_s32 = BMP280_INIT_VALUE;
/* read uncompensated pressure*/
   s32 v_data_uncomp_pres_s32 = BMP280_INIT_VALUE;
/* read real temperature*/
      double actual_temp = BMP280_INIT_VALUE;
/* read real pressure*/
   double actual_press = BMP280_INIT_VALUE;
/* Return status*/
s32 com_rslt = ERROR;
/* Set Baud */
pc_my.baud(115200);
//设置routine，将BMP280_SPI_bus_write/read传递给传感器读写
Bus_routine();
com_rslt=bmp280_init(&bmp280);
if(com_rslt==0)
      pc_my.printf("initialization succeed!\r\n");
else
      pc_my.printf("initialization failure!\r\n");
/*设置工作模式为Normal mode*/
com_rslt+= bmp280_set_power_mode(BMP280_NORMAL_MODE);
      if(com_rslt==0)
         pc_my.printf("set_power_mode succeed!\r\n");
      else
         pc_my.printf("set_power_mode failure!\r\n");
/* 标准分辨率，Standby时间1ms*/

bmp280_set_work_mode(BMP280_STANDARD_RESOLUTION_MODE);
bmp280_set_standby_durn(BMP280_STANDBY_TIME_1_MS);
bmp280_get_standby_durn(&v_standby_time_u8);
while(1){
   //读取数据：
      /* APIs are used to read the uncompensated temperature/pressure*/
      bmp280_read_uncomp_temperature(&v_data_uncomp_tem_s32);
      bmp280_read_uncomp_pressure(&v_data_uncomp_pres_s32);
      /* APIs are used to read the true temperature/pressure*/
      /* Input value as uncompensated temperature/pressure*/
      actual_temp = bmp280_compensate_temperature_double(v_data_uncomp_tem_s32);
      actual_press = bmp280_compensate_pressure_double(v_data_uncomp_pres_s32);
      pc_my.printf("The uncompensated temperature is= %d, The uncompensated pressure is= %d\r\n", v_data_uncomp_tem_s32, v_data_uncomp_pres_s32 );
      pc_my.printf("The actual temperature is= %f DegC, The actual pressure is= %f Pa\r\n ", actual_temp, actual_press);
      wait(2);

}
}