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 #include "bme280.h"
   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
  17 int fd;
  18
  19 int8_t user_i2c_read(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
  20 {
  21         write(fd, &reg_addr, 1);
  22         read(fd, data, len);
  23         return 0;
  24 }
  25
  26 void user_delay_ms(uint32_t period)
  27 {
  28         usleep(period * 1000);
  29 }
  30
  31 int8_t user_i2c_write(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
  32 {
  33         int8_t *buf;
  34         buf = malloc(len +1);
  35         buf[0] = reg_addr;
  36         memcpy(buf + 1, data, len);
  37         write(fd, buf, len + 1);
  38         free(buf);
  39         return 0;
  40 }
  41
  42 void print_sensor_data(struct bme280_data *comp_data)
  43 {
  44 #ifdef BME280_FLOAT_ENABLE
  45         printf("temp %0.2f, p %0.2f, hum %0.2f\n", comp_data->temperature, comp_data->pressure, comp_data->humidity);
  46 #else
  47         printf("temp %d, p %d, hum %d\n", comp_data->temperature, comp_data->pressure, comp_data->humidity);
  48 #endif
  49 }
  50
  51 int8_t stream_sensor_data_forced_mode(struct bme280_dev *dev)
  52 {
  53         int8_t rslt;
  54         uint8_t settings_sel;
  55         struct bme280_data comp_data;
  56
  57         /* Recommended mode of operation: Indoor navigation */
  58         dev->settings.osr_h = BME280_OVERSAMPLING_1X;
  59         dev->settings.osr_p = BME280_OVERSAMPLING_16X;
  60         dev->settings.osr_t = BME280_OVERSAMPLING_2X;
  61         dev->settings.filter = BME280_FILTER_COEFF_16;
  62
  63         settings_sel = BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL | BME280_OSR_HUM_SEL | BME280_FILTER_SEL;
  64
  65         rslt = bme280_set_sensor_settings(settings_sel, dev);
  66         if (rslt != BME280_OK)
  67         {
  68                 fprintf(stderr, "Failed to set sensor settings.");
  69                 return rslt;
  70         }
  71
  72         printf("Temperature, Pressure, Humidity\n");
  73         /* Continuously stream sensor data */
  74         while (1)
  75         {
  76                 rslt = bme280_set_sensor_mode(BME280_FORCED_MODE, dev);
  77                 if (rslt != BME280_OK)
  78                         break;
  79                 /* Wait for the measurement to complete and print data @25Hz */
  80                 dev->delay_ms(40);
  81                 rslt = bme280_get_sensor_data(BME280_ALL, &comp_data, dev);
  82                 if (rslt != BME280_OK)
  83                         break;
  84                 print_sensor_data(&comp_data);
  85         }
  86         return rslt;
  87 }
  88
  89 int main(int argc, char* argv[])
  90 {
  91         struct bme280_dev dev;
  92         int8_t rslt = BME280_OK;
  93
  94         if (argc < 2)
  95         {
  96                 fprintf(stderr, "Missing argument for i2c bus.\n");
  97                 exit(1);
  98         }
  99
 100         // make sure to select BME280_I2C_ADDR_PRIM
 101         // or BME280_I2C_ADDR_SEC as needed
 102         dev.dev_id =
 103 #if 1
 104                 BME280_I2C_ADDR_PRIM
 105 #else
 106                 BME280_I2C_ADDR_SEC
 107 #endif
 108                 ;
 109
 110         dev.intf = BME280_I2C_INTF;
 111         dev.read = user_i2c_read;
 112         dev.write = user_i2c_write;
 113         dev.delay_ms = user_delay_ms;
 114
 115         if ((fd = open(argv[1], O_RDWR)) < 0)
 116         {
 117                 fprintf(stderr, "Failed to open the i2c bus %s\n", argv[1]);
 118                 exit(1);
 119         }
 120         if (ioctl(fd, I2C_SLAVE, dev.dev_id) < 0)
 121         {
 122                 fprintf(stderr, "Failed to acquire bus access and/or talk to slave.\n");
 123                 exit(1);
 124         }
 125
 126         rslt = bme280_init(&dev);
 127         if (rslt != BME280_OK)
 128         {
 129                 fprintf(stderr, "Failed to initialize the device.\n");
 130                 exit(1);
 131         }
 132         rslt = stream_sensor_data_forced_mode(&dev);
 133         if (rslt != BME280_OK)
 134         {
 135                 fprintf(stderr, "Failed to stream sensor data.\n");
 136                 exit(1);
 137         }
 138         return 0;
 139 }