2 * collectd - src/barometer.c
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU Lesser General Public License as published by
6 * the Free Software Foundation; only version 2.1 of the License is
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public License
15 * along with this program; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
26 #include "utils_cache.h"
29 #include <linux/i2c-dev.h>
32 #include <sys/ioctl.h>
35 /* ------------ MPL115 defines ------------ */
36 /* I2C address of the MPL115 sensor */
37 #define MPL115_I2C_ADDRESS 0x60
39 /* register addresses */
40 #define MPL115_ADDR_CONV 0x00
41 #define MPL115_ADDR_COEFFS 0x04
44 #define MPL115_NUM_CONV 4
45 #define MPL115_NUM_COEFFS 12
47 /* commands / addresses */
48 #define MPL115_CMD_CONVERT_PRESS 0x10
49 #define MPL115_CMD_CONVERT_TEMP 0x11
50 #define MPL115_CMD_CONVERT_BOTH 0x12
52 #define MPL115_CONVERSION_RETRIES 5
54 /* ------------ MPL3115 defines ------------ */
55 /* MPL3115 I2C address */
56 #define MPL3115_I2C_ADDRESS 0x60
58 /* register addresses (only the interesting ones) */
59 #define MPL3115_REG_STATUS 0x00
60 #define MPL3115_REG_OUT_P_MSB 0x01
61 #define MPL3115_REG_OUT_P_CSB 0x02
62 #define MPL3115_REG_OUT_P_LSB 0x03
63 #define MPL3115_REG_OUT_T_MSB 0x04
64 #define MPL3115_REG_OUT_T_LSB 0x05
65 #define MPL3115_REG_DR_STATUS 0x06
66 #define MPL3115_REG_WHO_AM_I 0x0C
67 #define MPL3115_REG_SYSMOD 0x11
68 #define MPL3115_REG_PT_DATA_CFG 0x13
69 #define MPL3115_REG_BAR_IN_MSB 0x14
70 #define MPL3115_REG_BAR_IN_LSB 0x15
71 #define MPL3115_REG_CTRL_REG1 0x26
72 #define MPL3115_REG_CTRL_REG2 0x27
73 #define MPL3115_REG_CTRL_REG3 0x28
74 #define MPL3115_REG_CTRL_REG4 0x29
75 #define MPL3115_REG_CTRL_REG5 0x2A
76 #define MPL3115_REG_OFF_P 0x2B
77 #define MPL3115_REG_OFF_T 0x2C
78 #define MPL3115_REG_OFF_H 0x2D
80 /* Register values, masks */
81 #define MPL3115_WHO_AM_I_RESP 0xC4
83 #define MPL3115_PT_DATA_DREM 0x04
84 #define MPL3115_PT_DATA_PDEF 0x02
85 #define MPL3115_PT_DATA_TDEF 0x01
87 #define MPL3115_DR_STATUS_TDR 0x02
88 #define MPL3115_DR_STATUS_PDR 0x04
89 #define MPL3115_DR_STATUS_PTDR 0x08
90 #define MPL3115_DR_STATUS_DR \
91 (MPL3115_DR_STATUS_TDR | MPL3115_DR_STATUS_PDR | MPL3115_DR_STATUS_PTDR)
93 #define MPL3115_DR_STATUS_TOW 0x20
94 #define MPL3115_DR_STATUS_POW 0x40
95 #define MPL3115_DR_STATUS_PTOW 0x80
97 #define MPL3115_CTRL_REG1_ALT 0x80
98 #define MPL3115_CTRL_REG1_RAW 0x40
99 #define MPL3115_CTRL_REG1_OST_MASK 0x38
100 #define MPL3115_CTRL_REG1_OST_1 0x00
101 #define MPL3115_CTRL_REG1_OST_2 0x08
102 #define MPL3115_CTRL_REG1_OST_4 0x10
103 #define MPL3115_CTRL_REG1_OST_8 0x18
104 #define MPL3115_CTRL_REG1_OST_16 0x20
105 #define MPL3115_CTRL_REG1_OST_32 0x28
106 #define MPL3115_CTRL_REG1_OST_64 0x30
107 #define MPL3115_CTRL_REG1_OST_128 0x38
108 #define MPL3115_CTRL_REG1_RST 0x04
109 #define MPL3115_CTRL_REG1_OST 0x02
110 #define MPL3115_CTRL_REG1_SBYB 0x01
111 #define MPL3115_CTRL_REG1_SBYB_MASK 0xFE
113 #define MPL3115_NUM_CONV_VALS 5
115 /* ------------ BMP085 defines ------------ */
116 /* I2C address of the BMP085 sensor */
117 #define BMP085_I2C_ADDRESS 0x77
119 /* register addresses */
120 #define BMP085_ADDR_ID_REG 0xD0
121 #define BMP085_ADDR_VERSION 0xD1
123 #define BMP085_ADDR_CONV 0xF6
125 #define BMP085_ADDR_CTRL_REG 0xF4
126 #define BMP085_ADDR_COEFFS 0xAA
129 #define BMP085_NUM_COEFFS 22
131 /* commands, values */
132 #define BMP085_CHIP_ID 0x55
134 #define BMP085_CMD_CONVERT_TEMP 0x2E
136 #define BMP085_CMD_CONVERT_PRESS_0 0x34
137 #define BMP085_CMD_CONVERT_PRESS_1 0x74
138 #define BMP085_CMD_CONVERT_PRESS_2 0xB4
139 #define BMP085_CMD_CONVERT_PRESS_3 0xF4
142 #define BMP085_TIME_CNV_TEMP 4500
144 #define BMP085_TIME_CNV_PRESS_0 4500
145 #define BMP085_TIME_CNV_PRESS_1 7500
146 #define BMP085_TIME_CNV_PRESS_2 13500
147 #define BMP085_TIME_CNV_PRESS_3 25500
149 /* ------------ Normalization ------------ */
150 /* Mean sea level pressure normalization methods */
152 #define MSLP_INTERNATIONAL 1
153 #define MSLP_DEU_WETT 2
155 /** Temperature reference history depth for averaging. See
156 * #get_reference_temperature */
157 #define REF_TEMP_AVG_NUM 5
159 /* ------------------------------------------ */
161 /** Supported sensor types */
169 static const char *config_keys[] = {
172 "PressureOffset", /**< only for MPL3115 */
173 "TemperatureOffset", /**< only for MPL3115 */
176 "TemperatureSensor"};
178 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
180 static char *config_device = NULL; /**< I2C bus device */
181 static int config_oversample = 1; /**< averaging window */
183 static double config_press_offset = 0.0; /**< pressure offset */
184 static double config_temp_offset = 0.0; /**< temperature offset */
186 static double config_altitude = NAN; /**< altitude */
187 static int config_normalize = 0; /**< normalization method */
189 static _Bool configured = 0; /**< the whole plugin config status */
191 static int i2c_bus_fd = -1; /**< I2C bus device FD */
193 static enum Sensor_type sensor_type =
194 Sensor_none; /**< detected/used sensor type */
196 static __s32 mpl3115_oversample = 0; /**< MPL3115 CTRL1 oversample setting */
198 // BMP085 configuration
199 static unsigned bmp085_oversampling; /**< BMP085 oversampling (0-3) */
201 bmp085_timeCnvPress; /**< BMP085 conversion time for pressure in us */
202 static __u8 bmp085_cmdCnvPress; /**< BMP085 pressure conversion command */
204 /* MPL115 conversion coefficients */
205 static double mpl115_coeffA0;
206 static double mpl115_coeffB1;
207 static double mpl115_coeffB2;
208 static double mpl115_coeffC12;
209 static double mpl115_coeffC11;
210 static double mpl115_coeffC22;
212 /* BMP085 conversion coefficients */
213 static short bmp085_AC1;
214 static short bmp085_AC2;
215 static short bmp085_AC3;
216 static unsigned short bmp085_AC4;
217 static unsigned short bmp085_AC5;
218 static unsigned short bmp085_AC6;
219 static short bmp085_B1;
220 static short bmp085_B2;
221 static short bmp085_MB;
222 static short bmp085_MC;
223 static short bmp085_MD;
225 /* ------------------------ averaging ring buffer ------------------------ */
226 /* Used only for MPL115. MPL3115 supports real oversampling in the device so */
227 /* no need for any postprocessing. */
229 static _Bool avg_initialized = 0; /**< already initialized by real values */
231 typedef struct averaging_s {
232 long int *ring_buffer;
233 int ring_buffer_size;
234 long int ring_buffer_sum;
235 int ring_buffer_head;
238 static averaging_t pressure_averaging = {NULL, 0, 0L, 0};
239 static averaging_t temperature_averaging = {NULL, 0, 0L, 0};
242 * Create / allocate averaging buffer
244 * The buffer is initialized with zeros.
246 * @param avg pointer to ring buffer to be allocated
247 * @param size requested buffer size
249 * @return Zero when successful
251 static int averaging_create(averaging_t *avg, int size) {
252 avg->ring_buffer = calloc((size_t)size, sizeof(*avg->ring_buffer));
253 if (avg->ring_buffer == NULL) {
254 ERROR("barometer: averaging_create - ring buffer allocation of size %d "
260 avg->ring_buffer_size = size;
261 avg->ring_buffer_sum = 0L;
262 avg->ring_buffer_head = 0;
268 * Delete / free existing averaging buffer
270 * @param avg pointer to the ring buffer to be deleted
272 static void averaging_delete(averaging_t *avg) {
273 if (avg->ring_buffer != NULL) {
274 free(avg->ring_buffer);
275 avg->ring_buffer = NULL;
277 avg->ring_buffer_size = 0;
278 avg->ring_buffer_sum = 0L;
279 avg->ring_buffer_head = 0;
283 * Add new sample to the averaging buffer
285 * A new averaged value is returned. Note that till the buffer is full
286 * returned value is inaccurate as it is an average of real values and initial
289 * @param avg pointer to the ring buffer
290 * @param sample new sample value
292 * @return Averaged sample value
294 static double averaging_add_sample(averaging_t *avg, long int sample) {
297 avg->ring_buffer_sum += sample - avg->ring_buffer[avg->ring_buffer_head];
298 avg->ring_buffer[avg->ring_buffer_head] = sample;
299 avg->ring_buffer_head = (avg->ring_buffer_head + 1) % avg->ring_buffer_size;
300 result = (double)(avg->ring_buffer_sum) / (double)(avg->ring_buffer_size);
302 DEBUG("barometer: averaging_add_sample - added %ld, result = %lf", sample,
308 /* ------------------------ temperature refference ------------------------ */
311 * Linked list type of temperature sensor references
313 typedef struct temperature_list_s {
314 char *sensor_name; /**< sensor name/reference */
315 size_t num_values; /**< number of values (usually one) */
316 _Bool initialized; /**< sensor already provides data */
317 struct temperature_list_s *next; /**< next in the list */
318 } temperature_list_t;
320 static temperature_list_t *temp_list = NULL;
323 * Add new sensor to the temperature reference list
325 * @param list the list
326 * @param sensor reference name (as provided by the config file)
328 * @return Zero when successful
330 static int temp_list_add(temperature_list_t *list, const char *sensor) {
331 temperature_list_t *new_temp;
333 new_temp = malloc(sizeof(*new_temp));
334 if (new_temp == NULL)
337 new_temp->sensor_name = strdup(sensor);
338 new_temp->initialized = 0;
339 new_temp->num_values = 0;
340 if (new_temp->sensor_name == NULL) {
345 new_temp->next = temp_list;
346 temp_list = new_temp;
351 * Delete the whole temperature reference list
353 * @param list the list to be deleted
355 static void temp_list_delete(temperature_list_t **list) {
356 temperature_list_t *tmp;
358 while (*list != NULL) {
360 (*list) = (*list)->next;
361 free(tmp->sensor_name);
368 * Get reference temperature value
370 * First initially uc_get_rate_by_name is tried. At the startup due to
371 * nondeterministic order the temperature may not be read yet (then it fails and
372 * first measurment gives only absolute air pressure reading which is
373 * acceptable). Once it succedes (should be second measurement at the latest) we
374 * use average of few last readings from uc_get_history_by_name. It may take few
375 * readings to start filling so again we use uc_get_rate_by_name as a fallback.
376 * The idea is to use basic "noise" filtering (history averaging) across all the
377 * values which given sensor provides (up to given depth). Then we get minimum
380 * @param result where the result is stored. When not available NAN is stored.
382 * @return Zero when successful
384 static int get_reference_temperature(double *result) {
385 temperature_list_t *list = temp_list;
387 gauge_t *values = NULL; /**< rate values */
388 size_t values_num = 0; /**< number of rate values */
390 gauge_t values_history[REF_TEMP_AVG_NUM];
392 double avg_sum; /**< Value sum for computing average */
393 int avg_num; /**< Number of values for computing average */
394 double average; /**< Resulting value average */
398 while (list != NULL) {
402 /* First time need to read current rate to learn how many values are
403 there (typically for temperature it would be just one). We do not expect
404 dynamic changing of number of temperarure values in runtime yet (are
405 there any such cases?). */
406 if (!list->initialized) {
407 if (uc_get_rate_by_name(list->sensor_name, &values, &values_num)) {
409 "barometer: get_reference_temperature - rate \"%s\" not found yet",
415 DEBUG("barometer: get_reference_temperature - initialize \"%s\", %" PRIsz
417 list->sensor_name, values_num);
419 list->initialized = 1;
420 list->num_values = values_num;
422 for (size_t i = 0; i < values_num; ++i) {
423 DEBUG("barometer: get_reference_temperature - rate %" PRIsz ": %lf **",
425 if (!isnan(values[i])) {
426 avg_sum += values[i];
434 /* It is OK to get here the first time as well, in the worst case
435 the history will full of NANs. */
436 if (uc_get_history_by_name(list->sensor_name, values_history,
437 REF_TEMP_AVG_NUM, list->num_values)) {
438 ERROR("barometer: get_reference_temperature - history \"%s\" lost",
440 list->initialized = 0;
441 list->num_values = 0;
446 for (size_t i = 0; i < REF_TEMP_AVG_NUM * list->num_values; ++i) {
447 DEBUG("barometer: get_reference_temperature - history %" PRIsz ": %lf", i,
449 if (!isnan(values_history[i])) {
450 avg_sum += values_history[i];
455 if (avg_num == 0) /* still no history? fallback to current */
457 if (uc_get_rate_by_name(list->sensor_name, &values, &values_num)) {
458 ERROR("barometer: get_reference_temperature - rate \"%s\" lost",
460 list->initialized = 0;
461 list->num_values = 0;
466 for (size_t i = 0; i < values_num; ++i) {
467 DEBUG("barometer: get_reference_temperature - rate last %" PRIsz
470 if (!isnan(values[i])) {
471 avg_sum += values[i];
480 ERROR("barometer: get_reference_temperature - could not read \"%s\"",
482 list->initialized = 0;
483 list->num_values = 0;
485 average = avg_sum / (double)avg_num;
488 else if (*result > average)
492 } /* while sensor list */
494 if (*result == NAN) {
495 ERROR("barometer: get_reference_temperature - no sensor available (yet?)");
498 DEBUG("barometer: get_reference_temperature - temp is %lf", *result);
502 /* ------------------------ MPL115 access ------------------------ */
505 * Detect presence of a MPL115 pressure sensor.
507 * Unfortunately there seems to be no ID register so we just try to read first
508 * conversion coefficient from device at MPL115 address and hope it is really
509 * MPL115. We should use this check as the last resort (which would be the
511 * case anyway since MPL115 is the least accurate sensor).
512 * As a sideeffect will leave set I2C slave address.
514 * @return 1 if MPL115, 0 otherwise
516 static int MPL115_detect(void) {
519 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL115_I2C_ADDRESS) < 0) {
520 ERROR("barometer: MPL115_detect problem setting i2c slave address to "
522 MPL115_I2C_ADDRESS, STRERRNO);
526 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL115_ADDR_COEFFS);
528 DEBUG("barometer: MPL115_detect - positive detection");
532 DEBUG("barometer: MPL115_detect - negative detection");
537 * Read the MPL115 sensor conversion coefficients.
539 * These are (device specific) constants so we can read them just once.
541 * @return Zero when successful
543 static int MPL115_read_coeffs(void) {
544 uint8_t mpl115_coeffs[MPL115_NUM_COEFFS] = {0};
547 int8_t sia0MSB, sia0LSB, sib1MSB, sib1LSB, sib2MSB, sib2LSB;
548 int8_t sic12MSB, sic12LSB, sic11MSB, sic11LSB, sic22MSB, sic22LSB;
549 int16_t sia0, sib1, sib2, sic12, sic11, sic22;
551 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, MPL115_ADDR_COEFFS,
552 STATIC_ARRAY_SIZE(mpl115_coeffs),
555 ERROR("barometer: MPL115_read_coeffs - problem reading data: %s", STRERRNO);
559 /* Using perhaps less elegant/efficient code, but more readable. */
560 /* a0: 16total 1sign 12int 4fract 0pad */
561 sia0MSB = mpl115_coeffs[0];
562 sia0LSB = mpl115_coeffs[1];
563 sia0 = (int16_t)sia0MSB << 8; /* s16 type, Shift to MSB */
564 sia0 += (int16_t)sia0LSB & 0x00FF; /* Add LSB to 16bit number */
565 mpl115_coeffA0 = (double)(sia0);
566 mpl115_coeffA0 /= 8.0; /* 3 fract bits */
568 /* b1: 16total 1sign 2int 13fract 0pad */
569 sib1MSB = mpl115_coeffs[2];
570 sib1LSB = mpl115_coeffs[3];
571 sib1 = sib1MSB << 8; /* Shift to MSB */
572 sib1 += sib1LSB & 0x00FF; /* Add LSB to 16bit number */
573 mpl115_coeffB1 = (double)(sib1);
574 mpl115_coeffB1 /= 8192.0; /* 13 fract */
576 /* b2: 16total 1sign 1int 14fract 0pad */
577 sib2MSB = mpl115_coeffs[4];
578 sib2LSB = mpl115_coeffs[5];
579 sib2 = sib2MSB << 8; /* Shift to MSB */
580 sib2 += sib2LSB & 0x00FF; /* Add LSB to 16bit number */
581 mpl115_coeffB2 = (double)(sib2);
582 mpl115_coeffB2 /= 16384.0; /* 14 fract */
584 /* c12: 14total 1sign 0int 13fract 9pad */
585 sic12MSB = mpl115_coeffs[6];
586 sic12LSB = mpl115_coeffs[7];
587 sic12 = sic12MSB << 8; /* Shift to MSB only by 8 for MSB */
588 sic12 += sic12LSB & 0x00FF;
589 mpl115_coeffC12 = (double)(sic12);
590 mpl115_coeffC12 /= 4.0; /* 16-14=2 */
591 mpl115_coeffC12 /= 4194304.0; /* 13+9=22 fract */
593 /* c11: 11total 1sign 0int 11fract 11pad */
594 sic11MSB = mpl115_coeffs[8];
595 sic11LSB = mpl115_coeffs[9];
596 sic11 = sic11MSB << 8; /* Shift to MSB only by 8 for MSB */
597 sic11 += sic11LSB & 0x00FF;
598 mpl115_coeffC11 = (double)(sic11);
599 mpl115_coeffC11 /= 32.0; /* 16-11=5 */
600 mpl115_coeffC11 /= 4194304.0; /* 11+11=22 fract */
602 /* c12: 11total 1sign 0int 10fract 15pad */
603 sic22MSB = mpl115_coeffs[10];
604 sic22LSB = mpl115_coeffs[11];
605 sic22 = sic22MSB << 8; /* Shift to MSB only by 8 for MSB */
606 sic22 += sic22LSB & 0x00FF;
607 mpl115_coeffC22 = (double)(sic22);
608 mpl115_coeffC22 /= 32.0; // 16-11=5
609 mpl115_coeffC22 /= 33554432.0; /* 10+15=25 fract */
611 DEBUG("barometer: MPL115_read_coeffs: a0=%lf, b1=%lf, b2=%lf, c12=%lf, "
613 mpl115_coeffA0, mpl115_coeffB1, mpl115_coeffB2, mpl115_coeffC12,
614 mpl115_coeffC11, mpl115_coeffC22);
619 * Convert raw adc values to real data using the sensor coefficients.
621 * @param adc_pressure adc pressure value to be converted
622 * @param adc_temp adc temperature value to be converted
623 * @param pressure computed real pressure
624 * @param temperature computed real temperature
626 static void MPL115_convert_adc_to_real(double adc_pressure, double adc_temp,
627 double *pressure, double *temperature) {
629 Pcomp = mpl115_coeffA0 +
630 (mpl115_coeffB1 + mpl115_coeffC11 * adc_pressure +
631 mpl115_coeffC12 * adc_temp) *
633 (mpl115_coeffB2 + mpl115_coeffC22 * adc_temp) * adc_temp;
635 *pressure = ((1150.0 - 500.0) * Pcomp / 1023.0) + 500.0;
636 *temperature = (472.0 - adc_temp) / 5.35 + 25.0;
637 DEBUG("barometer: MPL115_convert_adc_to_real - got %lf hPa, %lf C", *pressure,
642 * Read sensor averegaed measurements
644 * @param pressure averaged measured pressure
645 * @param temperature averaged measured temperature
647 * @return Zero when successful
649 static int MPL115_read_averaged(double *pressure, double *temperature) {
650 uint8_t mpl115_conv[MPL115_NUM_CONV] = {0};
654 int conv_temperature;
656 double adc_temperature;
661 /* start conversion of both temp and presure */
662 retries = MPL115_CONVERSION_RETRIES;
663 while (retries > 0) {
664 /* write 1 to start conversion */
665 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL115_CMD_CONVERT_BOTH, 0x01);
671 ERROR("barometer: MPL115_read_averaged - requesting conversion: %s, "
672 "will retry at most %d more times",
675 ERROR("barometer: MPL115_read_averaged - requesting conversion: %s, "
676 "too many failed retries",
682 usleep(10000); /* wait 10ms for the conversion */
684 retries = MPL115_CONVERSION_RETRIES;
685 while (retries > 0) {
686 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, MPL115_ADDR_CONV,
687 STATIC_ARRAY_SIZE(mpl115_conv),
694 ERROR("barometer: MPL115_read_averaged - reading conversion: %s, "
695 "will retry at most %d more times",
698 ERROR("barometer: MPL115_read_averaged - reading conversion: %s, "
699 "too many failed retries",
705 conv_pressure = ((mpl115_conv[0] << 8) | mpl115_conv[1]) >> 6;
706 conv_temperature = ((mpl115_conv[2] << 8) | mpl115_conv[3]) >> 6;
707 DEBUG("barometer: MPL115_read_averaged, raw pressure ADC value = %d, "
708 "raw temperature ADC value = %d",
709 conv_pressure, conv_temperature);
711 adc_pressure = averaging_add_sample(&pressure_averaging, conv_pressure);
713 averaging_add_sample(&temperature_averaging, conv_temperature);
715 MPL115_convert_adc_to_real(adc_pressure, adc_temperature, pressure,
718 DEBUG("barometer: MPL115_read_averaged - averaged ADC pressure = %lf / "
719 "temperature = %lf, "
720 "real pressure = %lf hPa / temperature = %lf C",
721 adc_pressure, adc_temperature, *pressure, *temperature);
726 /* ------------------------ MPL3115 access ------------------------ */
729 * Detect presence of a MPL3115 pressure sensor by checking register "WHO AM I"
731 * As a sideeffect will leave set I2C slave address.
733 * @return 1 if MPL3115, 0 otherwise
735 static int MPL3115_detect(void) {
738 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL3115_I2C_ADDRESS) < 0) {
739 ERROR("barometer: MPL3115_detect problem setting i2c slave address to "
741 MPL3115_I2C_ADDRESS, STRERRNO);
745 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_WHO_AM_I);
746 if (res == MPL3115_WHO_AM_I_RESP) {
747 DEBUG("barometer: MPL3115_detect - positive detection");
751 DEBUG("barometer: MPL3115_detect - negative detection");
756 * Adjusts oversampling to values supported by MPL3115
758 * MPL3115 supports only power of 2 in the range 1 to 128.
760 static void MPL3115_adjust_oversampling(void) {
763 if (config_oversample > 100) {
765 mpl3115_oversample = MPL3115_CTRL_REG1_OST_128;
766 } else if (config_oversample > 48) {
768 mpl3115_oversample = MPL3115_CTRL_REG1_OST_64;
769 } else if (config_oversample > 24) {
771 mpl3115_oversample = MPL3115_CTRL_REG1_OST_32;
772 } else if (config_oversample > 12) {
774 mpl3115_oversample = MPL3115_CTRL_REG1_OST_16;
775 } else if (config_oversample > 6) {
777 mpl3115_oversample = MPL3115_CTRL_REG1_OST_8;
778 } else if (config_oversample > 3) {
780 mpl3115_oversample = MPL3115_CTRL_REG1_OST_4;
781 } else if (config_oversample > 1) {
783 mpl3115_oversample = MPL3115_CTRL_REG1_OST_2;
786 mpl3115_oversample = MPL3115_CTRL_REG1_OST_1;
789 DEBUG("barometer: MPL3115_adjust_oversampling - correcting oversampling from "
791 config_oversample, new_val);
792 config_oversample = new_val;
796 * Read sensor averaged measurements
798 * @param pressure averaged measured pressure
799 * @param temperature averaged measured temperature
801 * @return Zero when successful
803 static int MPL3115_read(double *pressure, double *temperature) {
806 __u8 data[MPL3115_NUM_CONV_VALS];
807 long int tmp_value = 0;
809 /* Set Active - activate the device from standby */
810 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1);
812 ERROR("barometer: MPL3115_read - cannot read CTRL_REG1: %s", STRERRNO);
816 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1,
817 ctrl | MPL3115_CTRL_REG1_SBYB);
819 ERROR("barometer: MPL3115_read - problem activating: %s", STRERRNO);
823 /* base sleep is 5ms x OST */
824 usleep(5000 * config_oversample);
826 /* check the flags/status if ready */
827 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
829 ERROR("barometer: MPL3115_read - cannot read status register: %s",
834 while ((res & MPL3115_DR_STATUS_DR) != MPL3115_DR_STATUS_DR) {
835 /* try some extra sleep... */
838 /* ... and repeat the check. The conversion has to finish sooner or later.
840 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
842 ERROR("barometer: MPL3115_read - cannot read status register: %s",
848 /* Now read all the data in one block. There is address autoincrement. */
849 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, MPL3115_REG_OUT_P_MSB,
850 MPL3115_NUM_CONV_VALS, data);
852 ERROR("barometer: MPL3115_read - cannot read data registers: %s", STRERRNO);
856 tmp_value = (data[0] << 16) | (data[1] << 8) | data[2];
857 *pressure = ((double)tmp_value) / 4.0 / 16.0 / 100.0;
858 DEBUG("barometer: MPL3115_read - absolute pressure = %lf hPa", *pressure);
860 if (data[3] > 0x7F) {
861 data[3] = ~data[3] + 1;
862 *temperature = data[3];
863 *temperature = -*temperature;
865 *temperature = data[3];
868 *temperature += (double)(data[4]) / 256.0;
869 DEBUG("barometer: MPL3115_read - temperature = %lf C", *temperature);
875 * Initialize MPL3115 for barometeric measurements
877 * @return 0 if successful
879 static int MPL3115_init_sensor(void) {
883 /* Reset the sensor. It will reset immediately without ACKing */
884 /* the transaction, so no error handling here. */
885 i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1,
886 MPL3115_CTRL_REG1_RST);
888 /* wait some time for the reset to finish */
891 /* now it should be in standby already so we can go and configure it */
893 /* Set temperature offset. */
894 /* result = ADCtemp + offset [C] */
895 offset = (__s8)(config_temp_offset * 16.0);
896 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_T, offset);
898 ERROR("barometer: MPL3115_init_sensor - problem setting temp offset: %s",
903 /* Set pressure offset. */
904 /* result = ADCpress + offset [hPa] */
905 offset = (__s8)(config_press_offset * 100.0 / 4.0);
906 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_P, offset);
909 "barometer: MPL3115_init_sensor - problem setting pressure offset: %s",
914 /* Enable Data Flags in PT_DATA_CFG - flags on both pressure and temp */
915 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_PT_DATA_CFG,
916 MPL3115_PT_DATA_DREM | MPL3115_PT_DATA_PDEF |
917 MPL3115_PT_DATA_TDEF);
919 ERROR("barometer: MPL3115_init_sensor - problem setting PT_DATA_CFG: %s",
924 /* Set to barometer with an OSR */
925 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1,
928 ERROR("barometer: MPL3115_init_sensor - problem configuring CTRL_REG1: %s",
936 /* ------------------------ BMP085 access ------------------------ */
939 * Detect presence of a BMP085 pressure sensor by checking its ID register
941 * As a sideeffect will leave set I2C slave address.
943 * @return 1 if BMP085, 0 otherwise
945 static int BMP085_detect(void) {
948 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, BMP085_I2C_ADDRESS) < 0) {
949 ERROR("barometer: BMP085_detect - problem setting i2c slave address to "
951 BMP085_I2C_ADDRESS, STRERRNO);
955 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_ID_REG);
956 if (res == BMP085_CHIP_ID) {
957 DEBUG("barometer: BMP085_detect - positive detection");
960 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_VERSION);
962 ERROR("barometer: BMP085_detect - problem checking chip version: %s",
966 DEBUG("barometer: BMP085_detect - chip version ML:0x%02X AL:0x%02X",
967 res & 0x0f, (res & 0xf0) >> 4);
971 DEBUG("barometer: BMP085_detect - negative detection");
976 * Adjusts oversampling settings to values supported by BMP085
978 * BMP085 supports only 1,2,4 or 8 samples.
980 static void BMP085_adjust_oversampling(void) {
983 if (config_oversample > 6) /* 8 */
986 bmp085_oversampling = 3;
987 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_3;
988 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_3;
989 } else if (config_oversample > 3) /* 4 */
992 bmp085_oversampling = 2;
993 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_2;
994 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_2;
995 } else if (config_oversample > 1) /* 2 */
998 bmp085_oversampling = 1;
999 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_1;
1000 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_1;
1004 bmp085_oversampling = 0;
1005 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_0;
1006 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_0;
1009 DEBUG("barometer: BMP085_adjust_oversampling - correcting oversampling from "
1011 config_oversample, new_val);
1012 config_oversample = new_val;
1016 * Read the BMP085 sensor conversion coefficients.
1018 * These are (device specific) constants so we can read them just once.
1020 * @return Zero when successful
1022 static int BMP085_read_coeffs(void) {
1024 __u8 coeffs[BMP085_NUM_COEFFS];
1026 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, BMP085_ADDR_COEFFS,
1027 BMP085_NUM_COEFFS, coeffs);
1029 ERROR("barometer: BMP085_read_coeffs - problem reading data: %s", STRERRNO);
1033 bmp085_AC1 = ((int16_t)coeffs[0] << 8) | (int16_t)coeffs[1];
1034 bmp085_AC2 = ((int16_t)coeffs[2] << 8) | (int16_t)coeffs[3];
1035 bmp085_AC3 = ((int16_t)coeffs[4] << 8) | (int16_t)coeffs[5];
1036 bmp085_AC4 = ((uint16_t)coeffs[6] << 8) | (uint16_t)coeffs[7];
1037 bmp085_AC5 = ((uint16_t)coeffs[8] << 8) | (uint16_t)coeffs[9];
1038 bmp085_AC6 = ((uint16_t)coeffs[10] << 8) | (uint16_t)coeffs[11];
1039 bmp085_B1 = ((int16_t)coeffs[12] << 8) | (int16_t)coeffs[13];
1040 bmp085_B2 = ((int16_t)coeffs[14] << 8) | (int16_t)coeffs[15];
1041 bmp085_MB = ((int16_t)coeffs[16] << 8) | (int16_t)coeffs[17];
1042 bmp085_MC = ((int16_t)coeffs[18] << 8) | (int16_t)coeffs[19];
1043 bmp085_MD = ((int16_t)coeffs[20] << 8) | (int16_t)coeffs[21];
1045 DEBUG("barometer: BMP085_read_coeffs - AC1=%d, AC2=%d, AC3=%d, AC4=%u,"
1046 " AC5=%u, AC6=%u, B1=%d, B2=%d, MB=%d, MC=%d, MD=%d",
1047 bmp085_AC1, bmp085_AC2, bmp085_AC3, bmp085_AC4, bmp085_AC5, bmp085_AC6,
1048 bmp085_B1, bmp085_B2, bmp085_MB, bmp085_MC, bmp085_MD);
1054 * Convert raw BMP085 adc values to real data using the sensor coefficients.
1056 * @param adc_pressure adc pressure value to be converted
1057 * @param adc_temp adc temperature value to be converted
1058 * @param pressure computed real pressure
1059 * @param temperature computed real temperature
1061 static void BMP085_convert_adc_to_real(long adc_pressure, long adc_temperature,
1062 double *pressure, double *temperature)
1067 unsigned long B4, B7;
1072 /* calculate real temperature */
1073 X1 = ((adc_temperature - bmp085_AC6) * bmp085_AC5) >> 15;
1074 X2 = (bmp085_MC << 11) / (X1 + bmp085_MD);
1079 *temperature = (double)T * 0.1;
1081 /* calculate real pressure */
1082 /* in general X1, X2, X3 are recycled while values of B3, B4, B5, B6 are kept
1087 X1 = ((bmp085_B2 * ((B6 * B6) >> 12)) >> 11);
1088 X2 = (((long)bmp085_AC2 * B6) >> 11);
1090 B3 = (((((long)bmp085_AC1 * 4) + X3) << bmp085_oversampling) + 2) >> 2;
1093 X1 = (((long)bmp085_AC3 * B6) >> 13);
1094 X2 = (bmp085_B1 * ((B6 * B6) >> 12)) >> 16;
1095 X3 = ((X1 + X2) + 2) >> 2;
1096 B4 = ((long)bmp085_AC4 * (unsigned long)(X3 + 32768)) >> 15;
1099 B7 = (unsigned long)(adc_pressure - B3) * (50000 >> bmp085_oversampling);
1100 if (B7 < 0x80000000) {
1105 X1 = (P >> 8) * (P >> 8);
1106 X1 = (X1 * 3038) >> 16;
1107 X2 = ((-7357) * P) >> 16;
1108 P = P + ((X1 + X2 + 3791) >> 4);
1110 *pressure = P / 100.0; // in [hPa]
1111 DEBUG("barometer: BMP085_convert_adc_to_real - got %lf hPa, %lf C", *pressure,
1116 * Read compensated sensor measurements
1118 * @param pressure averaged measured pressure
1119 * @param temperature averaged measured temperature
1121 * @return Zero when successful
1123 static int BMP085_read(double *pressure, double *temperature) {
1128 long adc_temperature;
1130 /* start conversion of temperature */
1131 res = i2c_smbus_write_byte_data(i2c_bus_fd, BMP085_ADDR_CTRL_REG,
1132 BMP085_CMD_CONVERT_TEMP);
1134 ERROR("barometer: BMP085_read - problem requesting temperature conversion: "
1140 usleep(BMP085_TIME_CNV_TEMP); /* wait for the conversion */
1143 i2c_smbus_read_i2c_block_data(i2c_bus_fd, BMP085_ADDR_CONV, 2, measBuff);
1145 ERROR("barometer: BMP085_read - problem reading temperature data: %s",
1150 adc_temperature = ((unsigned short)measBuff[0] << 8) + measBuff[1];
1153 res = i2c_smbus_write_byte_data(i2c_bus_fd, BMP085_ADDR_CTRL_REG,
1154 bmp085_cmdCnvPress);
1156 ERROR("barometer: BMP085_read - problem requesting pressure conversion: %s",
1161 usleep(bmp085_timeCnvPress); /* wait for the conversion */
1164 i2c_smbus_read_i2c_block_data(i2c_bus_fd, BMP085_ADDR_CONV, 3, measBuff);
1166 ERROR("barometer: BMP085_read - problem reading pressure data: %s",
1171 adc_pressure = (long)((((ulong)measBuff[0] << 16) |
1172 ((ulong)measBuff[1] << 8) | (ulong)measBuff[2]) >>
1173 (8 - bmp085_oversampling));
1175 DEBUG("barometer: BMP085_read - raw pressure ADC value = %ld, "
1176 "raw temperature ADC value = %ld",
1177 adc_pressure, adc_temperature);
1179 BMP085_convert_adc_to_real(adc_pressure, adc_temperature, pressure,
1185 /* ------------------------ Sensor detection ------------------------ */
1187 * Detect presence of a supported sensor.
1189 * As a sideeffect will leave set I2C slave address.
1190 * The detection is done in the order BMP085, MPL3115, MPL115 and stops after
1191 * first sensor beeing found.
1193 * @return detected sensor type
1195 static enum Sensor_type detect_sensor_type(void) {
1196 if (BMP085_detect())
1197 return Sensor_BMP085;
1199 else if (MPL3115_detect())
1200 return Sensor_MPL3115;
1202 else if (MPL115_detect())
1203 return Sensor_MPL115;
1208 /* ------------------------ Common functionality ------------------------ */
1211 * Convert absolute pressure (in hPa) to mean sea level pressure
1213 * Implemented methods are:
1214 * - MSLP_NONE - no converions, returns absolute pressure
1216 * - MSLP_INTERNATIONAL - see
1217 * http://en.wikipedia.org/wiki/Atmospheric_pressure#Altitude_atmospheric_pressure_variation
1218 * Requires #config_altitude
1220 * - MSLP_DEU_WETT - formula as recommended by the Deutsche Wetterdienst. See
1221 * http://de.wikipedia.org/wiki/Barometrische_H%C3%B6henformel#Theorie
1222 * Requires both #config_altitude and temperature reference(s).
1224 * @param abs_pressure absloute pressure to be converted
1226 * @return mean sea level pressure if successful, NAN otherwise
1228 static double abs_to_mean_sea_level_pressure(double abs_pressure) {
1233 if (config_normalize >= MSLP_DEU_WETT) {
1234 result = get_reference_temperature(&temp);
1240 switch (config_normalize) {
1242 mean = abs_pressure;
1245 case MSLP_INTERNATIONAL:
1246 mean = abs_pressure / pow(1.0 - 0.0065 * config_altitude / 288.15,
1247 9.80665 * 0.0289644 / (8.31447 * 0.0065));
1250 case MSLP_DEU_WETT: {
1251 double E; /* humidity */
1254 E = 5.6402 * (-0.0916 + exp(0.06 * temp));
1256 E = 18.2194 * (1.0463 - exp(-0.0666 * temp));
1258 (287.05 * (temp + 273.15 + 0.12 * E + 0.0065 * config_altitude / 2)) *
1260 mean = abs_pressure * exp(x);
1265 "barometer: abs_to_mean_sea_level_pressure: wrong conversion method %d",
1267 mean = abs_pressure;
1271 DEBUG("barometer: abs_to_mean_sea_level_pressure: absPressure = %lf hPa, "
1272 "method = %d, meanPressure = %lf hPa",
1273 abs_pressure, config_normalize, mean);
1278 /* ------------------------ main plugin callbacks ------------------------ */
1281 * Main plugin configuration callback (using simple config)
1283 * @param key configuration key we should process
1284 * @param value configuration value we should process
1286 * @return Zero when successful.
1288 static int collectd_barometer_config(const char *key, const char *value) {
1289 DEBUG("barometer: collectd_barometer_config");
1291 if (strcasecmp(key, "Device") == 0) {
1292 sfree(config_device);
1293 config_device = strdup(value);
1294 } else if (strcasecmp(key, "Oversampling") == 0) {
1295 int oversampling_tmp = atoi(value);
1296 if (oversampling_tmp < 1 || oversampling_tmp > 1024) {
1297 WARNING("barometer: collectd_barometer_config: invalid oversampling: %d."
1298 " Allowed values are 1 to 1024 (for MPL115) or 1 to 128 (for "
1299 "MPL3115) or 1 to 8 (for BMP085).",
1303 config_oversample = oversampling_tmp;
1304 } else if (strcasecmp(key, "Altitude") == 0) {
1305 config_altitude = atof(value);
1306 } else if (strcasecmp(key, "Normalization") == 0) {
1307 int normalize_tmp = atoi(value);
1308 if (normalize_tmp < 0 || normalize_tmp > 2) {
1309 WARNING("barometer: collectd_barometer_config: invalid normalization: %d",
1313 config_normalize = normalize_tmp;
1314 } else if (strcasecmp(key, "TemperatureSensor") == 0) {
1315 if (temp_list_add(temp_list, value)) {
1318 } else if (strcasecmp(key, "PressureOffset") == 0) {
1319 config_press_offset = atof(value);
1320 } else if (strcasecmp(key, "TemperatureOffset") == 0) {
1321 config_temp_offset = atof(value);
1330 * Shutdown callback.
1332 * Close I2C and delete all the buffers.
1334 * @return Zero when successful (at the moment the only possible outcome)
1336 static int collectd_barometer_shutdown(void) {
1337 DEBUG("barometer: collectd_barometer_shutdown");
1339 if (sensor_type == Sensor_MPL115) {
1340 averaging_delete(&pressure_averaging);
1341 averaging_delete(&temperature_averaging);
1343 temp_list_delete(&temp_list);
1346 if (i2c_bus_fd > 0) {
1349 sfree(config_device);
1356 * Plugin read callback for MPL115.
1358 * Dispatching will create values:
1359 * - <hostname>/barometer-mpl115/pressure-normalized
1360 * - <hostname>/barometer-mpl115/pressure-absolute
1361 * - <hostname>/barometer-mpl115/temperature
1363 * @return Zero when successful.
1365 static int MPL115_collectd_barometer_read(void) {
1368 double pressure = 0.0;
1369 double temperature = 0.0;
1370 double norm_pressure = 0.0;
1372 value_list_t vl = VALUE_LIST_INIT;
1375 DEBUG("barometer: MPL115_collectd_barometer_read");
1381 /* Rather than delaying init, we will intitialize during first read. This
1382 way at least we have a better chance to have the reference temperature
1383 already available. */
1384 if (!avg_initialized) {
1385 for (int i = 0; i < config_oversample - 1; ++i) {
1386 result = MPL115_read_averaged(&pressure, &temperature);
1388 ERROR("barometer: MPL115_collectd_barometer_read - mpl115 read, "
1389 "ignored during init");
1391 DEBUG("barometer: MPL115_collectd_barometer_read - init %d / %d", i + 1,
1392 config_oversample - 1);
1395 avg_initialized = 1;
1398 result = MPL115_read_averaged(&pressure, &temperature);
1402 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1404 sstrncpy(vl.plugin, "barometer", sizeof(vl.plugin));
1405 sstrncpy(vl.plugin_instance, "mpl115", sizeof(vl.plugin_instance));
1410 /* dispatch normalized air pressure */
1411 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1412 sstrncpy(vl.type_instance, "normalized", sizeof(vl.type_instance));
1413 values[0].gauge = norm_pressure;
1414 plugin_dispatch_values(&vl);
1416 /* dispatch absolute air pressure */
1417 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1418 sstrncpy(vl.type_instance, "absolute", sizeof(vl.type_instance));
1419 values[0].gauge = pressure;
1420 plugin_dispatch_values(&vl);
1422 /* dispatch sensor temperature */
1423 sstrncpy(vl.type, "temperature", sizeof(vl.type));
1424 sstrncpy(vl.type_instance, "", sizeof(vl.type_instance));
1425 values[0].gauge = temperature;
1426 plugin_dispatch_values(&vl);
1432 * Plugin read callback for MPL3115.
1434 * Dispatching will create values:
1435 * - <hostname>/barometer-mpl3115/pressure-normalized
1436 * - <hostname>/barometer-mpl3115/pressure-absolute
1437 * - <hostname>/barometer-mpl3115/temperature
1439 * @return Zero when successful.
1441 static int MPL3115_collectd_barometer_read(void) {
1444 double pressure = 0.0;
1445 double temperature = 0.0;
1446 double norm_pressure = 0.0;
1448 value_list_t vl = VALUE_LIST_INIT;
1451 DEBUG("barometer: MPL3115_collectd_barometer_read");
1457 result = MPL3115_read(&pressure, &temperature);
1461 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1463 sstrncpy(vl.plugin, "barometer", sizeof(vl.plugin));
1464 sstrncpy(vl.plugin_instance, "mpl3115", sizeof(vl.plugin_instance));
1469 /* dispatch normalized air pressure */
1470 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1471 sstrncpy(vl.type_instance, "normalized", sizeof(vl.type_instance));
1472 values[0].gauge = norm_pressure;
1473 plugin_dispatch_values(&vl);
1475 /* dispatch absolute air pressure */
1476 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1477 sstrncpy(vl.type_instance, "absolute", sizeof(vl.type_instance));
1478 values[0].gauge = pressure;
1479 plugin_dispatch_values(&vl);
1481 /* dispatch sensor temperature */
1482 sstrncpy(vl.type, "temperature", sizeof(vl.type));
1483 sstrncpy(vl.type_instance, "", sizeof(vl.type_instance));
1484 values[0].gauge = temperature;
1485 plugin_dispatch_values(&vl);
1491 * Plugin read callback for BMP085.
1493 * Dispatching will create values:
1494 * - <hostname>/barometer-bmp085/pressure-normalized
1495 * - <hostname>/barometer-bmp085/pressure-absolute
1496 * - <hostname>/barometer-bmp085/temperature
1498 * @return Zero when successful.
1500 static int BMP085_collectd_barometer_read(void) {
1503 double pressure = 0.0;
1504 double temperature = 0.0;
1505 double norm_pressure = 0.0;
1507 value_list_t vl = VALUE_LIST_INIT;
1510 DEBUG("barometer: BMP085_collectd_barometer_read");
1516 result = BMP085_read(&pressure, &temperature);
1520 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1522 sstrncpy(vl.plugin, "barometer", sizeof(vl.plugin));
1523 sstrncpy(vl.plugin_instance, "bmp085", sizeof(vl.plugin_instance));
1528 /* dispatch normalized air pressure */
1529 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1530 sstrncpy(vl.type_instance, "normalized", sizeof(vl.type_instance));
1531 values[0].gauge = norm_pressure;
1532 plugin_dispatch_values(&vl);
1534 /* dispatch absolute air pressure */
1535 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1536 sstrncpy(vl.type_instance, "absolute", sizeof(vl.type_instance));
1537 values[0].gauge = pressure;
1538 plugin_dispatch_values(&vl);
1540 /* dispatch sensor temperature */
1541 sstrncpy(vl.type, "temperature", sizeof(vl.type));
1542 sstrncpy(vl.type_instance, "", sizeof(vl.type_instance));
1543 values[0].gauge = temperature;
1544 plugin_dispatch_values(&vl);
1550 * Initialization callback
1552 * Check config, initialize I2C bus access, conversion coefficients and
1556 * @return Zero when successful.
1558 static int collectd_barometer_init(void) {
1560 DEBUG("barometer: collectd_barometer_init");
1562 if (config_device == NULL) {
1563 ERROR("barometer: collectd_barometer_init I2C bus device not configured");
1567 if (config_normalize >= MSLP_INTERNATIONAL && isnan(config_altitude)) {
1568 ERROR("barometer: collectd_barometer_init no altitude configured "
1569 "for mean sea level pressure normalization.");
1573 if (config_normalize == MSLP_DEU_WETT && temp_list == NULL) {
1574 ERROR("barometer: collectd_barometer_init no temperature reference "
1575 "configured for mean sea level pressure normalization.");
1579 i2c_bus_fd = open(config_device, O_RDWR);
1580 if (i2c_bus_fd < 0) {
1581 ERROR("barometer: collectd_barometer_init problem opening I2C bus device "
1582 "\"%s\": %s (is loaded mod i2c-dev?)",
1583 config_device, STRERRNO);
1587 /* detect sensor type - this will also set slave address */
1588 sensor_type = detect_sensor_type();
1590 /* init correct sensor type */
1591 switch (sensor_type) {
1593 case Sensor_MPL3115: {
1594 MPL3115_adjust_oversampling();
1596 if (MPL3115_init_sensor())
1599 plugin_register_read("barometer", MPL3115_collectd_barometer_read);
1603 case Sensor_MPL115: {
1604 if (averaging_create(&pressure_averaging, config_oversample)) {
1606 "barometer: collectd_barometer_init pressure averaging init failed");
1610 if (averaging_create(&temperature_averaging, config_oversample)) {
1611 ERROR("barometer: collectd_barometer_init temperature averaging init "
1616 if (MPL115_read_coeffs() < 0)
1619 plugin_register_read("barometer", MPL115_collectd_barometer_read);
1623 case Sensor_BMP085: {
1624 BMP085_adjust_oversampling();
1626 if (BMP085_read_coeffs() < 0)
1629 plugin_register_read("barometer", BMP085_collectd_barometer_read);
1632 /* anything else -> error */
1634 ERROR("barometer: collectd_barometer_init - no supported sensor found");
1642 /* ------------------------ plugin register / entry point
1643 * ------------------------ */
1646 * Plugin "entry" - register all callback.
1649 void module_register(void) {
1650 plugin_register_config("barometer", collectd_barometer_config, config_keys,
1652 plugin_register_init("barometer", collectd_barometer_init);
1653 plugin_register_shutdown("barometer", collectd_barometer_shutdown);