git.itanic.dy.fi Git - BME280_driver/blob - examples/linux_userspace.c

   1 /*
   2         Linux userspace test code, simple and mose code directy from the doco.
   3         compile like this: gcc linux_userspace.c ../bme280.c -I ../ -o bme280
   4         tested: Raspberry Pi.
   5         Use like: ./bme280 /dev/i2c-0
   6 */
   7
   8 #include <string.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <linux/i2c-dev.h>
  13 #include <sys/ioctl.h>
  14 #include <sys/types.h>
  15 #include <fcntl.h>
  16 #include "bme280.h"
  17
  18 int fd;
  19
  20 int8_t user_i2c_read(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
  21 {
  22         if (write(fd, &reg_addr, sizeof(reg_addr)) < sizeof(reg_addr))
  23                 return BME280_E_COMM_FAIL;
  24         if (read(fd, data, len) < len)
  25                 return BME280_E_COMM_FAIL;
  26         return BME280_OK;
  27 }
  28
  29 void user_delay_ms(uint32_t period)
  30 {
  31         usleep(period * 1000);
  32 }
  33
  34 int8_t user_i2c_write(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
  35 {
  36         int8_t *buf;
  37         buf = malloc(len + 1);
  38         buf[0] = reg_addr;
  39         memcpy(buf + 1, data, len);
  40         if (write(fd, buf, len + 1) < len)
  41                 return BME280_E_COMM_FAIL;
  42         free(buf);
  43         return BME280_OK;
  44 }
  45
  46 void print_sensor_data(struct bme280_data *comp_data)
  47 {
  48         float temp, press, hum;
  49 #ifdef BME280_FLOAT_ENABLE
  50         temp = comp_data->temperature;
  51         press = 0.01 * comp_data->pressure;
  52         hum = comp_data->humidity;
  53 #else
  54 #ifdef BME280_64BIT_ENABLE
  55         temp = 0.01f * comp_data->temperature;
  56         press = 0.0001f * comp_data->pressure;
  57         hum = 1.0f / 1024.0f * comp_data->humidity;
  58 #else
  59         temp = 0.01f * comp_data->temperature;
  60         press = 0.01f * comp_data->pressure;
  61         hum = 1.0f / 1024.0f * comp_data->humidity;
  62 #endif
  63 #endif
  64         printf("%0.2lf deg C, %0.2lf hPa, %0.2lf%%\n", temp, press, hum);
  65 }
  66
  67 int8_t stream_sensor_data_forced_mode(struct bme280_dev *dev)
  68 {
  69         int8_t rslt;
  70         uint8_t settings_sel;
  71         struct bme280_data comp_data;
  72
  73         /* Recommended mode of operation: Indoor navigation */
  74         dev->settings.osr_h = BME280_OVERSAMPLING_1X;
  75         dev->settings.osr_p = BME280_OVERSAMPLING_16X;
  76         dev->settings.osr_t = BME280_OVERSAMPLING_2X;
  77         dev->settings.filter = BME280_FILTER_COEFF_16;
  78
  79         settings_sel = BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL | BME280_OSR_HUM_SEL | BME280_FILTER_SEL;
  80
  81         rslt = bme280_set_sensor_settings(settings_sel, dev);
  82         if (rslt != BME280_OK)
  83         {
  84                 fprintf(stderr, "Failed to set sensor settings (code %+d).", rslt);
  85                 return rslt;
  86         }
  87
  88         printf("Temperature, Pressure, Humidity\n");
  89         /* Continuously stream sensor data */
  90         while (1)
  91         {
  92                 rslt = bme280_set_sensor_mode(BME280_FORCED_MODE, dev);
  93                 if (rslt != BME280_OK)
  94                 {
  95                         fprintf(stderr, "Failed to set sensor mode (code %+d).", rslt);
  96                         break;
  97                 }
  98                 /* Wait for the measurement to complete and print data @25Hz */
  99                 dev->delay_ms(40);
 100                 rslt = bme280_get_sensor_data(BME280_ALL, &comp_data, dev);
 101                 if (rslt != BME280_OK)
 102                 {
 103                         fprintf(stderr, "Failed to get sensor data (code %+d).", rslt);
 104                         break;
 105                 }
 106                 print_sensor_data(&comp_data);
 107         }
 108         return rslt;
 109 }
 110
 111 int main(int argc, char* argv[])
 112 {
 113         struct bme280_dev dev;
 114         int8_t rslt = BME280_OK;
 115
 116         if (argc < 2)
 117         {
 118                 fprintf(stderr, "Missing argument for i2c bus.\n");
 119                 exit(1);
 120         }
 121
 122         // make sure to select BME280_I2C_ADDR_PRIM
 123         // or BME280_I2C_ADDR_SEC as needed
 124         dev.dev_id =
 125 #if 1
 126                 BME280_I2C_ADDR_PRIM
 127 #else
 128                 BME280_I2C_ADDR_SEC
 129 #endif
 130                 ;
 131
 132         dev.intf = BME280_I2C_INTF;
 133         dev.read = user_i2c_read;
 134         dev.write = user_i2c_write;
 135         dev.delay_ms = user_delay_ms;
 136
 137         if ((fd = open(argv[1], O_RDWR)) < 0)
 138         {
 139                 fprintf(stderr, "Failed to open the i2c bus %s\n", argv[1]);
 140                 exit(1);
 141         }
 142         if (ioctl(fd, I2C_SLAVE, dev.dev_id) < 0)
 143         {
 144                 fprintf(stderr, "Failed to acquire bus access and/or talk to slave.\n");
 145                 exit(1);
 146         }
 147
 148         rslt = bme280_init(&dev);
 149         if (rslt != BME280_OK)
 150         {
 151                 fprintf(stderr, "Failed to initialize the device (code %+d).\n", rslt);
 152                 exit(1);
 153         }
 154         rslt = stream_sensor_data_forced_mode(&dev);
 155         if (rslt != BME280_OK)
 156         {
 157                 fprintf(stderr, "Failed to stream sensor data (code %+d).\n", rslt);
 158                 exit(1);
 159         }
 160         return 0;
 161 }