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
5 Use like: ./bme280 /dev/i2c-0
12 #include <linux/i2c-dev.h>
13 #include <sys/ioctl.h>
14 #include <sys/types.h>
20 int8_t user_i2c_read(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
22 if (write(fd, ®_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;
29 void user_delay_ms(uint32_t period)
31 usleep(period * 1000);
34 int8_t user_i2c_write(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
37 buf = malloc(len + 1);
39 memcpy(buf + 1, data, len);
40 if (write(fd, buf, len + 1) < len)
41 return BME280_E_COMM_FAIL;
46 void print_sensor_data(struct bme280_data *comp_data)
48 #ifdef BME280_FLOAT_ENABLE
49 printf("temp %0.2f, p %0.2f, hum %0.2f\n", comp_data->temperature, comp_data->pressure, comp_data->humidity);
51 printf("temp %d, p %d, hum %d\n", comp_data->temperature, comp_data->pressure, comp_data->humidity);
55 int8_t stream_sensor_data_forced_mode(struct bme280_dev *dev)
59 struct bme280_data comp_data;
61 /* Recommended mode of operation: Indoor navigation */
62 dev->settings.osr_h = BME280_OVERSAMPLING_1X;
63 dev->settings.osr_p = BME280_OVERSAMPLING_16X;
64 dev->settings.osr_t = BME280_OVERSAMPLING_2X;
65 dev->settings.filter = BME280_FILTER_COEFF_16;
67 settings_sel = BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL | BME280_OSR_HUM_SEL | BME280_FILTER_SEL;
69 rslt = bme280_set_sensor_settings(settings_sel, dev);
70 if (rslt != BME280_OK)
72 fprintf(stderr, "Failed to set sensor settings (code %+d).", rslt);
76 printf("Temperature, Pressure, Humidity\n");
77 /* Continuously stream sensor data */
80 rslt = bme280_set_sensor_mode(BME280_FORCED_MODE, dev);
81 if (rslt != BME280_OK)
83 fprintf(stderr, "Failed to set sensor mode (code %+d).", rslt);
86 /* Wait for the measurement to complete and print data @25Hz */
88 rslt = bme280_get_sensor_data(BME280_ALL, &comp_data, dev);
89 if (rslt != BME280_OK)
91 fprintf(stderr, "Failed to get sensor data (code %+d).", rslt);
94 print_sensor_data(&comp_data);
99 int main(int argc, char* argv[])
101 struct bme280_dev dev;
102 int8_t rslt = BME280_OK;
106 fprintf(stderr, "Missing argument for i2c bus.\n");
110 // make sure to select BME280_I2C_ADDR_PRIM
111 // or BME280_I2C_ADDR_SEC as needed
120 dev.intf = BME280_I2C_INTF;
121 dev.read = user_i2c_read;
122 dev.write = user_i2c_write;
123 dev.delay_ms = user_delay_ms;
125 if ((fd = open(argv[1], O_RDWR)) < 0)
127 fprintf(stderr, "Failed to open the i2c bus %s\n", argv[1]);
130 if (ioctl(fd, I2C_SLAVE, dev.dev_id) < 0)
132 fprintf(stderr, "Failed to acquire bus access and/or talk to slave.\n");
136 rslt = bme280_init(&dev);
137 if (rslt != BME280_OK)
139 fprintf(stderr, "Failed to initialize the device (code %+d).\n", rslt);
142 rslt = stream_sensor_data_forced_mode(&dev);
143 if (rslt != BME280_OK)
145 fprintf(stderr, "Failed to stream sensor data (code %+d).\n", rslt);