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
372 * order the temperature may not be read yet (then it fails and first measurment
374 * only absolute air pressure reading which is acceptable). Once it succedes
376 * second measurement at the latest) we use average of few last readings from
377 * uc_get_history_by_name. It may take few readings to start filling so again we
379 * uc_get_rate_by_name as a fallback.
380 * The idea is to use basic "noise" filtering (history averaging) across all the
382 * which given sensor provides (up to given depth). Then we get minimum among
385 * @param result where the result is stored. When not available NAN is stored.
387 * @return Zero when successful
389 static int get_reference_temperature(double *result) {
390 temperature_list_t *list = temp_list;
392 gauge_t *values = NULL; /**< rate values */
393 size_t values_num = 0; /**< number of rate values */
395 gauge_t values_history[REF_TEMP_AVG_NUM];
397 double avg_sum; /**< Value sum for computing average */
398 int avg_num; /**< Number of values for computing average */
399 double average; /**< Resulting value average */
403 while (list != NULL) {
407 /* First time need to read current rate to learn how many values are
408 there (typically for temperature it would be just one).
409 We do not expect dynamic changing of number of temperarure values
410 in runtime yet (are there any such cases?). */
411 if (!list->initialized) {
412 if (uc_get_rate_by_name(list->sensor_name, &values, &values_num)) {
414 "barometer: get_reference_temperature - rate \"%s\" not found yet",
421 "barometer: get_reference_temperature - initialize \"%s\", %zu vals",
422 list->sensor_name, values_num);
424 list->initialized = 1;
425 list->num_values = values_num;
427 for (size_t i = 0; i < values_num; ++i) {
428 DEBUG("barometer: get_reference_temperature - rate %zu: %lf **", i,
430 if (!isnan(values[i])) {
431 avg_sum += values[i];
439 /* It is OK to get here the first time as well, in the worst case
440 the history will full of NANs. */
441 if (uc_get_history_by_name(list->sensor_name, values_history,
442 REF_TEMP_AVG_NUM, list->num_values)) {
443 ERROR("barometer: get_reference_temperature - history \"%s\" lost",
445 list->initialized = 0;
446 list->num_values = 0;
451 for (size_t i = 0; i < REF_TEMP_AVG_NUM * list->num_values; ++i) {
452 DEBUG("barometer: get_reference_temperature - history %zu: %lf", i,
454 if (!isnan(values_history[i])) {
455 avg_sum += values_history[i];
460 if (avg_num == 0) /* still no history? fallback to current */
462 if (uc_get_rate_by_name(list->sensor_name, &values, &values_num)) {
463 ERROR("barometer: get_reference_temperature - rate \"%s\" lost",
465 list->initialized = 0;
466 list->num_values = 0;
471 for (size_t i = 0; i < values_num; ++i) {
472 DEBUG("barometer: get_reference_temperature - rate last %zu: %lf **", i,
474 if (!isnan(values[i])) {
475 avg_sum += values[i];
484 ERROR("barometer: get_reference_temperature - could not read \"%s\"",
486 list->initialized = 0;
487 list->num_values = 0;
489 average = avg_sum / (double)avg_num;
492 else if (*result > average)
496 } /* while sensor list */
498 if (*result == NAN) {
499 ERROR("barometer: get_reference_temperature - no sensor available (yet?)");
502 DEBUG("barometer: get_reference_temperature - temp is %lf", *result);
506 /* ------------------------ MPL115 access ------------------------ */
509 * Detect presence of a MPL115 pressure sensor.
511 * Unfortunately there seems to be no ID register so we just try to read first
512 * conversion coefficient from device at MPL115 address and hope it is really
513 * MPL115. We should use this check as the last resort (which would be the
515 * case anyway since MPL115 is the least accurate sensor).
516 * As a sideeffect will leave set I2C slave address.
518 * @return 1 if MPL115, 0 otherwise
520 static int MPL115_detect(void) {
524 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL115_I2C_ADDRESS) < 0) {
525 ERROR("barometer: MPL115_detect problem setting i2c slave address to "
527 MPL115_I2C_ADDRESS, sstrerror(errno, errbuf, sizeof(errbuf)));
531 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL115_ADDR_COEFFS);
533 DEBUG("barometer: MPL115_detect - positive detection");
537 DEBUG("barometer: MPL115_detect - negative detection");
542 * Read the MPL115 sensor conversion coefficients.
544 * These are (device specific) constants so we can read them just once.
546 * @return Zero when successful
548 static int MPL115_read_coeffs(void) {
549 uint8_t mpl115_coeffs[MPL115_NUM_COEFFS] = {0};
552 int8_t sia0MSB, sia0LSB, sib1MSB, sib1LSB, sib2MSB, sib2LSB;
553 int8_t sic12MSB, sic12LSB, sic11MSB, sic11LSB, sic22MSB, sic22LSB;
554 int16_t sia0, sib1, sib2, sic12, sic11, sic22;
558 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, MPL115_ADDR_COEFFS,
559 STATIC_ARRAY_SIZE(mpl115_coeffs),
562 ERROR("barometer: MPL115_read_coeffs - problem reading data: %s",
563 sstrerror(errno, errbuf, sizeof(errbuf)));
567 /* Using perhaps less elegant/efficient code, but more readable. */
568 /* a0: 16total 1sign 12int 4fract 0pad */
569 sia0MSB = mpl115_coeffs[0];
570 sia0LSB = mpl115_coeffs[1];
571 sia0 = (int16_t)sia0MSB << 8; /* s16 type, Shift to MSB */
572 sia0 += (int16_t)sia0LSB & 0x00FF; /* Add LSB to 16bit number */
573 mpl115_coeffA0 = (double)(sia0);
574 mpl115_coeffA0 /= 8.0; /* 3 fract bits */
576 /* b1: 16total 1sign 2int 13fract 0pad */
577 sib1MSB = mpl115_coeffs[2];
578 sib1LSB = mpl115_coeffs[3];
579 sib1 = sib1MSB << 8; /* Shift to MSB */
580 sib1 += sib1LSB & 0x00FF; /* Add LSB to 16bit number */
581 mpl115_coeffB1 = (double)(sib1);
582 mpl115_coeffB1 /= 8192.0; /* 13 fract */
584 /* b2: 16total 1sign 1int 14fract 0pad */
585 sib2MSB = mpl115_coeffs[4];
586 sib2LSB = mpl115_coeffs[5];
587 sib2 = sib2MSB << 8; /* Shift to MSB */
588 sib2 += sib2LSB & 0x00FF; /* Add LSB to 16bit number */
589 mpl115_coeffB2 = (double)(sib2);
590 mpl115_coeffB2 /= 16384.0; /* 14 fract */
592 /* c12: 14total 1sign 0int 13fract 9pad */
593 sic12MSB = mpl115_coeffs[6];
594 sic12LSB = mpl115_coeffs[7];
595 sic12 = sic12MSB << 8; /* Shift to MSB only by 8 for MSB */
596 sic12 += sic12LSB & 0x00FF;
597 mpl115_coeffC12 = (double)(sic12);
598 mpl115_coeffC12 /= 4.0; /* 16-14=2 */
599 mpl115_coeffC12 /= 4194304.0; /* 13+9=22 fract */
601 /* c11: 11total 1sign 0int 11fract 11pad */
602 sic11MSB = mpl115_coeffs[8];
603 sic11LSB = mpl115_coeffs[9];
604 sic11 = sic11MSB << 8; /* Shift to MSB only by 8 for MSB */
605 sic11 += sic11LSB & 0x00FF;
606 mpl115_coeffC11 = (double)(sic11);
607 mpl115_coeffC11 /= 32.0; /* 16-11=5 */
608 mpl115_coeffC11 /= 4194304.0; /* 11+11=22 fract */
610 /* c12: 11total 1sign 0int 10fract 15pad */
611 sic22MSB = mpl115_coeffs[10];
612 sic22LSB = mpl115_coeffs[11];
613 sic22 = sic22MSB << 8; /* Shift to MSB only by 8 for MSB */
614 sic22 += sic22LSB & 0x00FF;
615 mpl115_coeffC22 = (double)(sic22);
616 mpl115_coeffC22 /= 32.0; // 16-11=5
617 mpl115_coeffC22 /= 33554432.0; /* 10+15=25 fract */
619 DEBUG("barometer: MPL115_read_coeffs: a0=%lf, b1=%lf, b2=%lf, c12=%lf, "
621 mpl115_coeffA0, mpl115_coeffB1, mpl115_coeffB2, mpl115_coeffC12,
622 mpl115_coeffC11, mpl115_coeffC22);
627 * Convert raw adc values to real data using the sensor coefficients.
629 * @param adc_pressure adc pressure value to be converted
630 * @param adc_temp adc temperature value to be converted
631 * @param pressure computed real pressure
632 * @param temperature computed real temperature
634 static void MPL115_convert_adc_to_real(double adc_pressure, double adc_temp,
635 double *pressure, double *temperature) {
637 Pcomp = mpl115_coeffA0 +
638 (mpl115_coeffB1 + mpl115_coeffC11 * adc_pressure +
639 mpl115_coeffC12 * adc_temp) *
641 (mpl115_coeffB2 + mpl115_coeffC22 * adc_temp) * adc_temp;
643 *pressure = ((1150.0 - 500.0) * Pcomp / 1023.0) + 500.0;
644 *temperature = (472.0 - adc_temp) / 5.35 + 25.0;
645 DEBUG("barometer: MPL115_convert_adc_to_real - got %lf hPa, %lf C", *pressure,
650 * Read sensor averegaed measurements
652 * @param pressure averaged measured pressure
653 * @param temperature averaged measured temperature
655 * @return Zero when successful
657 static int MPL115_read_averaged(double *pressure, double *temperature) {
658 uint8_t mpl115_conv[MPL115_NUM_CONV] = {0};
662 int conv_temperature;
664 double adc_temperature;
670 /* start conversion of both temp and presure */
671 retries = MPL115_CONVERSION_RETRIES;
672 while (retries > 0) {
673 /* write 1 to start conversion */
674 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL115_CMD_CONVERT_BOTH, 0x01);
680 ERROR("barometer: MPL115_read_averaged - requesting conversion: %s, "
681 "will retry at most %d more times",
682 sstrerror(errno, errbuf, sizeof(errbuf)), retries);
684 ERROR("barometer: MPL115_read_averaged - requesting conversion: %s, "
685 "too many failed retries",
686 sstrerror(errno, errbuf, sizeof(errbuf)));
691 usleep(10000); /* wait 10ms for the conversion */
693 retries = MPL115_CONVERSION_RETRIES;
694 while (retries > 0) {
695 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, MPL115_ADDR_CONV,
696 STATIC_ARRAY_SIZE(mpl115_conv),
703 ERROR("barometer: MPL115_read_averaged - reading conversion: %s, "
704 "will retry at most %d more times",
705 sstrerror(errno, errbuf, sizeof(errbuf)), retries);
707 ERROR("barometer: MPL115_read_averaged - reading conversion: %s, "
708 "too many failed retries",
709 sstrerror(errno, errbuf, sizeof(errbuf)));
714 conv_pressure = ((mpl115_conv[0] << 8) | mpl115_conv[1]) >> 6;
715 conv_temperature = ((mpl115_conv[2] << 8) | mpl115_conv[3]) >> 6;
716 DEBUG("barometer: MPL115_read_averaged, raw pressure ADC value = %d, "
717 "raw temperature ADC value = %d",
718 conv_pressure, conv_temperature);
720 adc_pressure = averaging_add_sample(&pressure_averaging, conv_pressure);
722 averaging_add_sample(&temperature_averaging, conv_temperature);
724 MPL115_convert_adc_to_real(adc_pressure, adc_temperature, pressure,
727 DEBUG("barometer: MPL115_read_averaged - averaged ADC pressure = %lf / "
728 "temperature = %lf, "
729 "real pressure = %lf hPa / temperature = %lf C",
730 adc_pressure, adc_temperature, *pressure, *temperature);
735 /* ------------------------ MPL3115 access ------------------------ */
738 * Detect presence of a MPL3115 pressure sensor by checking register "WHO AM I"
740 * As a sideeffect will leave set I2C slave address.
742 * @return 1 if MPL3115, 0 otherwise
744 static int MPL3115_detect(void) {
748 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL3115_I2C_ADDRESS) < 0) {
749 ERROR("barometer: MPL3115_detect problem setting i2c slave address to "
751 MPL3115_I2C_ADDRESS, sstrerror(errno, errbuf, sizeof(errbuf)));
755 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_WHO_AM_I);
756 if (res == MPL3115_WHO_AM_I_RESP) {
757 DEBUG("barometer: MPL3115_detect - positive detection");
761 DEBUG("barometer: MPL3115_detect - negative detection");
766 * Adjusts oversampling to values supported by MPL3115
768 * MPL3115 supports only power of 2 in the range 1 to 128.
770 static void MPL3115_adjust_oversampling(void) {
773 if (config_oversample > 100) {
775 mpl3115_oversample = MPL3115_CTRL_REG1_OST_128;
776 } else if (config_oversample > 48) {
778 mpl3115_oversample = MPL3115_CTRL_REG1_OST_64;
779 } else if (config_oversample > 24) {
781 mpl3115_oversample = MPL3115_CTRL_REG1_OST_32;
782 } else if (config_oversample > 12) {
784 mpl3115_oversample = MPL3115_CTRL_REG1_OST_16;
785 } else if (config_oversample > 6) {
787 mpl3115_oversample = MPL3115_CTRL_REG1_OST_8;
788 } else if (config_oversample > 3) {
790 mpl3115_oversample = MPL3115_CTRL_REG1_OST_4;
791 } else if (config_oversample > 1) {
793 mpl3115_oversample = MPL3115_CTRL_REG1_OST_2;
796 mpl3115_oversample = MPL3115_CTRL_REG1_OST_1;
799 DEBUG("barometer: MPL3115_adjust_oversampling - correcting oversampling from "
801 config_oversample, new_val);
802 config_oversample = new_val;
806 * Read sensor averaged measurements
808 * @param pressure averaged measured pressure
809 * @param temperature averaged measured temperature
811 * @return Zero when successful
813 static int MPL3115_read(double *pressure, double *temperature) {
816 __u8 data[MPL3115_NUM_CONV_VALS];
817 long int tmp_value = 0;
820 /* Set Active - activate the device from standby */
821 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1);
823 ERROR("barometer: MPL3115_read - cannot read CTRL_REG1: %s",
824 sstrerror(errno, errbuf, sizeof(errbuf)));
828 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1,
829 ctrl | MPL3115_CTRL_REG1_SBYB);
831 ERROR("barometer: MPL3115_read - problem activating: %s",
832 sstrerror(errno, errbuf, sizeof(errbuf)));
836 /* base sleep is 5ms x OST */
837 usleep(5000 * config_oversample);
839 /* check the flags/status if ready */
840 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
842 ERROR("barometer: MPL3115_read - cannot read status register: %s",
843 sstrerror(errno, errbuf, sizeof(errbuf)));
847 while ((res & MPL3115_DR_STATUS_DR) != MPL3115_DR_STATUS_DR) {
848 /* try some extra sleep... */
851 /* ... and repeat the check. The conversion has to finish sooner or later.
853 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
855 ERROR("barometer: MPL3115_read - cannot read status register: %s",
856 sstrerror(errno, errbuf, sizeof(errbuf)));
861 /* Now read all the data in one block. There is address autoincrement. */
862 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, MPL3115_REG_OUT_P_MSB,
863 MPL3115_NUM_CONV_VALS, data);
865 ERROR("barometer: MPL3115_read - cannot read data registers: %s",
866 sstrerror(errno, errbuf, sizeof(errbuf)));
870 tmp_value = (data[0] << 16) | (data[1] << 8) | data[2];
871 *pressure = ((double)tmp_value) / 4.0 / 16.0 / 100.0;
872 DEBUG("barometer: MPL3115_read - absolute pressure = %lf hPa", *pressure);
874 if (data[3] > 0x7F) {
875 data[3] = ~data[3] + 1;
876 *temperature = data[3];
877 *temperature = -*temperature;
879 *temperature = data[3];
882 *temperature += (double)(data[4]) / 256.0;
883 DEBUG("barometer: MPL3115_read - temperature = %lf C", *temperature);
889 * Initialize MPL3115 for barometeric measurements
891 * @return 0 if successful
893 static int MPL3115_init_sensor(void) {
898 /* Reset the sensor. It will reset immediately without ACKing */
899 /* the transaction, so no error handling here. */
900 i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1,
901 MPL3115_CTRL_REG1_RST);
903 /* wait some time for the reset to finish */
906 /* now it should be in standby already so we can go and configure it */
908 /* Set temperature offset. */
909 /* result = ADCtemp + offset [C] */
910 offset = (__s8)(config_temp_offset * 16.0);
911 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_T, offset);
913 ERROR("barometer: MPL3115_init_sensor - problem setting temp offset: %s",
914 sstrerror(errno, errbuf, sizeof(errbuf)));
918 /* Set pressure offset. */
919 /* result = ADCpress + offset [hPa] */
920 offset = (__s8)(config_press_offset * 100.0 / 4.0);
921 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_P, offset);
924 "barometer: MPL3115_init_sensor - problem setting pressure offset: %s",
925 sstrerror(errno, errbuf, sizeof(errbuf)));
929 /* Enable Data Flags in PT_DATA_CFG - flags on both pressure and temp */
930 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_PT_DATA_CFG,
931 MPL3115_PT_DATA_DREM | MPL3115_PT_DATA_PDEF |
932 MPL3115_PT_DATA_TDEF);
934 ERROR("barometer: MPL3115_init_sensor - problem setting PT_DATA_CFG: %s",
935 sstrerror(errno, errbuf, sizeof(errbuf)));
939 /* Set to barometer with an OSR */
940 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1,
943 ERROR("barometer: MPL3115_init_sensor - problem configuring CTRL_REG1: %s",
944 sstrerror(errno, errbuf, sizeof(errbuf)));
951 /* ------------------------ BMP085 access ------------------------ */
954 * Detect presence of a BMP085 pressure sensor by checking its ID register
956 * As a sideeffect will leave set I2C slave address.
958 * @return 1 if BMP085, 0 otherwise
960 static int BMP085_detect(void) {
964 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, BMP085_I2C_ADDRESS) < 0) {
965 ERROR("barometer: BMP085_detect - problem setting i2c slave address to "
967 BMP085_I2C_ADDRESS, sstrerror(errno, errbuf, sizeof(errbuf)));
971 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_ID_REG);
972 if (res == BMP085_CHIP_ID) {
973 DEBUG("barometer: BMP085_detect - positive detection");
976 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_VERSION);
978 ERROR("barometer: BMP085_detect - problem checking chip version: %s",
979 sstrerror(errno, errbuf, sizeof(errbuf)));
982 DEBUG("barometer: BMP085_detect - chip version ML:0x%02X AL:0x%02X",
983 res & 0x0f, (res & 0xf0) >> 4);
987 DEBUG("barometer: BMP085_detect - negative detection");
992 * Adjusts oversampling settings to values supported by BMP085
994 * BMP085 supports only 1,2,4 or 8 samples.
996 static void BMP085_adjust_oversampling(void) {
999 if (config_oversample > 6) /* 8 */
1002 bmp085_oversampling = 3;
1003 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_3;
1004 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_3;
1005 } else if (config_oversample > 3) /* 4 */
1008 bmp085_oversampling = 2;
1009 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_2;
1010 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_2;
1011 } else if (config_oversample > 1) /* 2 */
1014 bmp085_oversampling = 1;
1015 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_1;
1016 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_1;
1020 bmp085_oversampling = 0;
1021 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_0;
1022 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_0;
1025 DEBUG("barometer: BMP085_adjust_oversampling - correcting oversampling from "
1027 config_oversample, new_val);
1028 config_oversample = new_val;
1032 * Read the BMP085 sensor conversion coefficients.
1034 * These are (device specific) constants so we can read them just once.
1036 * @return Zero when successful
1038 static int BMP085_read_coeffs(void) {
1040 __u8 coeffs[BMP085_NUM_COEFFS];
1043 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, BMP085_ADDR_COEFFS,
1044 BMP085_NUM_COEFFS, coeffs);
1046 ERROR("barometer: BMP085_read_coeffs - problem reading data: %s",
1047 sstrerror(errno, errbuf, sizeof(errbuf)));
1051 bmp085_AC1 = ((int16_t)coeffs[0] << 8) | (int16_t)coeffs[1];
1052 bmp085_AC2 = ((int16_t)coeffs[2] << 8) | (int16_t)coeffs[3];
1053 bmp085_AC3 = ((int16_t)coeffs[4] << 8) | (int16_t)coeffs[5];
1054 bmp085_AC4 = ((uint16_t)coeffs[6] << 8) | (uint16_t)coeffs[7];
1055 bmp085_AC5 = ((uint16_t)coeffs[8] << 8) | (uint16_t)coeffs[9];
1056 bmp085_AC6 = ((uint16_t)coeffs[10] << 8) | (uint16_t)coeffs[11];
1057 bmp085_B1 = ((int16_t)coeffs[12] << 8) | (int16_t)coeffs[13];
1058 bmp085_B2 = ((int16_t)coeffs[14] << 8) | (int16_t)coeffs[15];
1059 bmp085_MB = ((int16_t)coeffs[16] << 8) | (int16_t)coeffs[17];
1060 bmp085_MC = ((int16_t)coeffs[18] << 8) | (int16_t)coeffs[19];
1061 bmp085_MD = ((int16_t)coeffs[20] << 8) | (int16_t)coeffs[21];
1063 DEBUG("barometer: BMP085_read_coeffs - AC1=%d, AC2=%d, AC3=%d, AC4=%u,"
1064 " AC5=%u, AC6=%u, B1=%d, B2=%d, MB=%d, MC=%d, MD=%d",
1065 bmp085_AC1, bmp085_AC2, bmp085_AC3, bmp085_AC4, bmp085_AC5, bmp085_AC6,
1066 bmp085_B1, bmp085_B2, bmp085_MB, bmp085_MC, bmp085_MD);
1072 * Convert raw BMP085 adc values to real data using the sensor coefficients.
1074 * @param adc_pressure adc pressure value to be converted
1075 * @param adc_temp adc temperature value to be converted
1076 * @param pressure computed real pressure
1077 * @param temperature computed real temperature
1079 static void BMP085_convert_adc_to_real(long adc_pressure, long adc_temperature,
1080 double *pressure, double *temperature)
1085 unsigned long B4, B7;
1090 /* calculate real temperature */
1091 X1 = ((adc_temperature - bmp085_AC6) * bmp085_AC5) >> 15;
1092 X2 = (bmp085_MC << 11) / (X1 + bmp085_MD);
1097 *temperature = (double)T * 0.1;
1099 /* calculate real pressure */
1100 /* in general X1, X2, X3 are recycled while values of B3, B4, B5, B6 are kept
1105 X1 = ((bmp085_B2 * ((B6 * B6) >> 12)) >> 11);
1106 X2 = (((long)bmp085_AC2 * B6) >> 11);
1108 B3 = (((((long)bmp085_AC1 * 4) + X3) << bmp085_oversampling) + 2) >> 2;
1111 X1 = (((long)bmp085_AC3 * B6) >> 13);
1112 X2 = (bmp085_B1 * ((B6 * B6) >> 12)) >> 16;
1113 X3 = ((X1 + X2) + 2) >> 2;
1114 B4 = ((long)bmp085_AC4 * (unsigned long)(X3 + 32768)) >> 15;
1117 B7 = (unsigned long)(adc_pressure - B3) * (50000 >> bmp085_oversampling);
1118 if (B7 < 0x80000000) {
1123 X1 = (P >> 8) * (P >> 8);
1124 X1 = (X1 * 3038) >> 16;
1125 X2 = ((-7357) * P) >> 16;
1126 P = P + ((X1 + X2 + 3791) >> 4);
1128 *pressure = P / 100.0; // in [hPa]
1129 DEBUG("barometer: BMP085_convert_adc_to_real - got %lf hPa, %lf C", *pressure,
1134 * Read compensated sensor measurements
1136 * @param pressure averaged measured pressure
1137 * @param temperature averaged measured temperature
1139 * @return Zero when successful
1141 static int BMP085_read(double *pressure, double *temperature) {
1146 long adc_temperature;
1150 /* start conversion of temperature */
1151 res = i2c_smbus_write_byte_data(i2c_bus_fd, BMP085_ADDR_CTRL_REG,
1152 BMP085_CMD_CONVERT_TEMP);
1154 ERROR("barometer: BMP085_read - problem requesting temperature conversion: "
1156 sstrerror(errno, errbuf, sizeof(errbuf)));
1160 usleep(BMP085_TIME_CNV_TEMP); /* wait for the conversion */
1163 i2c_smbus_read_i2c_block_data(i2c_bus_fd, BMP085_ADDR_CONV, 2, measBuff);
1165 ERROR("barometer: BMP085_read - problem reading temperature data: %s",
1166 sstrerror(errno, errbuf, sizeof(errbuf)));
1170 adc_temperature = ((unsigned short)measBuff[0] << 8) + measBuff[1];
1173 res = i2c_smbus_write_byte_data(i2c_bus_fd, BMP085_ADDR_CTRL_REG,
1174 bmp085_cmdCnvPress);
1176 ERROR("barometer: BMP085_read - problem requesting pressure conversion: %s",
1177 sstrerror(errno, errbuf, sizeof(errbuf)));
1181 usleep(bmp085_timeCnvPress); /* wait for the conversion */
1184 i2c_smbus_read_i2c_block_data(i2c_bus_fd, BMP085_ADDR_CONV, 3, measBuff);
1186 ERROR("barometer: BMP085_read - problem reading pressure data: %s",
1187 sstrerror(errno, errbuf, sizeof(errbuf)));
1191 adc_pressure = (long)((((ulong)measBuff[0] << 16) |
1192 ((ulong)measBuff[1] << 8) | (ulong)measBuff[2]) >>
1193 (8 - bmp085_oversampling));
1195 DEBUG("barometer: BMP085_read - raw pressure ADC value = %ld, "
1196 "raw temperature ADC value = %ld",
1197 adc_pressure, adc_temperature);
1199 BMP085_convert_adc_to_real(adc_pressure, adc_temperature, pressure,
1205 /* ------------------------ Sensor detection ------------------------ */
1207 * Detect presence of a supported sensor.
1209 * As a sideeffect will leave set I2C slave address.
1210 * The detection is done in the order BMP085, MPL3115, MPL115 and stops after
1211 * first sensor beeing found.
1213 * @return detected sensor type
1215 static enum Sensor_type detect_sensor_type(void) {
1216 if (BMP085_detect())
1217 return Sensor_BMP085;
1219 else if (MPL3115_detect())
1220 return Sensor_MPL3115;
1222 else if (MPL115_detect())
1223 return Sensor_MPL115;
1228 /* ------------------------ Common functionality ------------------------ */
1231 * Convert absolute pressure (in hPa) to mean sea level pressure
1233 * Implemented methods are:
1234 * - MSLP_NONE - no converions, returns absolute pressure
1236 * - MSLP_INTERNATIONAL - see
1237 * http://en.wikipedia.org/wiki/Atmospheric_pressure#Altitude_atmospheric_pressure_variation
1238 * Requires #config_altitude
1240 * - MSLP_DEU_WETT - formula as recommended by the Deutsche Wetterdienst. See
1241 * http://de.wikipedia.org/wiki/Barometrische_H%C3%B6henformel#Theorie
1242 * Requires both #config_altitude and temperature reference(s).
1244 * @param abs_pressure absloute pressure to be converted
1246 * @return mean sea level pressure if successful, NAN otherwise
1248 static double abs_to_mean_sea_level_pressure(double abs_pressure) {
1253 if (config_normalize >= MSLP_DEU_WETT) {
1254 result = get_reference_temperature(&temp);
1260 switch (config_normalize) {
1262 mean = abs_pressure;
1265 case MSLP_INTERNATIONAL:
1266 mean = abs_pressure / pow(1.0 - 0.0065 * config_altitude / 288.15,
1267 9.80665 * 0.0289644 / (8.31447 * 0.0065));
1270 case MSLP_DEU_WETT: {
1271 double E; /* humidity */
1274 E = 5.6402 * (-0.0916 + exp(0.06 * temp));
1276 E = 18.2194 * (1.0463 - exp(-0.0666 * temp));
1278 (287.05 * (temp + 273.15 + 0.12 * E + 0.0065 * config_altitude / 2)) *
1280 mean = abs_pressure * exp(x);
1285 "barometer: abs_to_mean_sea_level_pressure: wrong conversion method %d",
1287 mean = abs_pressure;
1291 DEBUG("barometer: abs_to_mean_sea_level_pressure: absPressure = %lf hPa, "
1292 "method = %d, meanPressure = %lf hPa",
1293 abs_pressure, config_normalize, mean);
1298 /* ------------------------ main plugin callbacks ------------------------ */
1301 * Main plugin configuration callback (using simple config)
1303 * @param key configuration key we should process
1304 * @param value configuration value we should process
1306 * @return Zero when successful.
1308 static int collectd_barometer_config(const char *key, const char *value) {
1309 DEBUG("barometer: collectd_barometer_config");
1311 if (strcasecmp(key, "Device") == 0) {
1312 sfree(config_device);
1313 config_device = strdup(value);
1314 } else if (strcasecmp(key, "Oversampling") == 0) {
1315 int oversampling_tmp = atoi(value);
1316 if (oversampling_tmp < 1 || oversampling_tmp > 1024) {
1317 WARNING("barometer: collectd_barometer_config: invalid oversampling: %d."
1318 " Allowed values are 1 to 1024 (for MPL115) or 1 to 128 (for "
1319 "MPL3115) or 1 to 8 (for BMP085).",
1323 config_oversample = oversampling_tmp;
1324 } else if (strcasecmp(key, "Altitude") == 0) {
1325 config_altitude = atof(value);
1326 } else if (strcasecmp(key, "Normalization") == 0) {
1327 int normalize_tmp = atoi(value);
1328 if (normalize_tmp < 0 || normalize_tmp > 2) {
1329 WARNING("barometer: collectd_barometer_config: invalid normalization: %d",
1333 config_normalize = normalize_tmp;
1334 } else if (strcasecmp(key, "TemperatureSensor") == 0) {
1335 if (temp_list_add(temp_list, value)) {
1338 } else if (strcasecmp(key, "PressureOffset") == 0) {
1339 config_press_offset = atof(value);
1340 } else if (strcasecmp(key, "TemperatureOffset") == 0) {
1341 config_temp_offset = atof(value);
1350 * Shutdown callback.
1352 * Close I2C and delete all the buffers.
1354 * @return Zero when successful (at the moment the only possible outcome)
1356 static int collectd_barometer_shutdown(void) {
1357 DEBUG("barometer: collectd_barometer_shutdown");
1359 if (sensor_type == Sensor_MPL115) {
1360 averaging_delete(&pressure_averaging);
1361 averaging_delete(&temperature_averaging);
1363 temp_list_delete(&temp_list);
1366 if (i2c_bus_fd > 0) {
1369 sfree(config_device);
1376 * Plugin read callback for MPL115.
1378 * Dispatching will create values:
1379 * - <hostname>/barometer-mpl115/pressure-normalized
1380 * - <hostname>/barometer-mpl115/pressure-absolute
1381 * - <hostname>/barometer-mpl115/temperature
1383 * @return Zero when successful.
1385 static int MPL115_collectd_barometer_read(void) {
1388 double pressure = 0.0;
1389 double temperature = 0.0;
1390 double norm_pressure = 0.0;
1392 value_list_t vl = VALUE_LIST_INIT;
1395 DEBUG("barometer: MPL115_collectd_barometer_read");
1401 /* Rather than delaying init, we will intitialize during first read. This
1402 way at least we have a better chance to have the reference temperature
1403 already available. */
1404 if (!avg_initialized) {
1405 for (int i = 0; i < config_oversample - 1; ++i) {
1406 result = MPL115_read_averaged(&pressure, &temperature);
1408 ERROR("barometer: MPL115_collectd_barometer_read - mpl115 read, "
1409 "ignored during init");
1411 DEBUG("barometer: MPL115_collectd_barometer_read - init %d / %d", i + 1,
1412 config_oversample - 1);
1415 avg_initialized = 1;
1418 result = MPL115_read_averaged(&pressure, &temperature);
1422 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1424 sstrncpy(vl.plugin, "barometer", sizeof(vl.plugin));
1425 sstrncpy(vl.plugin_instance, "mpl115", sizeof(vl.plugin_instance));
1430 /* dispatch normalized air pressure */
1431 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1432 sstrncpy(vl.type_instance, "normalized", sizeof(vl.type_instance));
1433 values[0].gauge = norm_pressure;
1434 plugin_dispatch_values(&vl);
1436 /* dispatch absolute air pressure */
1437 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1438 sstrncpy(vl.type_instance, "absolute", sizeof(vl.type_instance));
1439 values[0].gauge = pressure;
1440 plugin_dispatch_values(&vl);
1442 /* dispatch sensor temperature */
1443 sstrncpy(vl.type, "temperature", sizeof(vl.type));
1444 sstrncpy(vl.type_instance, "", sizeof(vl.type_instance));
1445 values[0].gauge = temperature;
1446 plugin_dispatch_values(&vl);
1452 * Plugin read callback for MPL3115.
1454 * Dispatching will create values:
1455 * - <hostname>/barometer-mpl3115/pressure-normalized
1456 * - <hostname>/barometer-mpl3115/pressure-absolute
1457 * - <hostname>/barometer-mpl3115/temperature
1459 * @return Zero when successful.
1461 static int MPL3115_collectd_barometer_read(void) {
1464 double pressure = 0.0;
1465 double temperature = 0.0;
1466 double norm_pressure = 0.0;
1468 value_list_t vl = VALUE_LIST_INIT;
1471 DEBUG("barometer: MPL3115_collectd_barometer_read");
1477 result = MPL3115_read(&pressure, &temperature);
1481 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1483 sstrncpy(vl.plugin, "barometer", sizeof(vl.plugin));
1484 sstrncpy(vl.plugin_instance, "mpl3115", sizeof(vl.plugin_instance));
1489 /* dispatch normalized air pressure */
1490 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1491 sstrncpy(vl.type_instance, "normalized", sizeof(vl.type_instance));
1492 values[0].gauge = norm_pressure;
1493 plugin_dispatch_values(&vl);
1495 /* dispatch absolute air pressure */
1496 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1497 sstrncpy(vl.type_instance, "absolute", sizeof(vl.type_instance));
1498 values[0].gauge = pressure;
1499 plugin_dispatch_values(&vl);
1501 /* dispatch sensor temperature */
1502 sstrncpy(vl.type, "temperature", sizeof(vl.type));
1503 sstrncpy(vl.type_instance, "", sizeof(vl.type_instance));
1504 values[0].gauge = temperature;
1505 plugin_dispatch_values(&vl);
1511 * Plugin read callback for BMP085.
1513 * Dispatching will create values:
1514 * - <hostname>/barometer-bmp085/pressure-normalized
1515 * - <hostname>/barometer-bmp085/pressure-absolute
1516 * - <hostname>/barometer-bmp085/temperature
1518 * @return Zero when successful.
1520 static int BMP085_collectd_barometer_read(void) {
1523 double pressure = 0.0;
1524 double temperature = 0.0;
1525 double norm_pressure = 0.0;
1527 value_list_t vl = VALUE_LIST_INIT;
1530 DEBUG("barometer: BMP085_collectd_barometer_read");
1536 result = BMP085_read(&pressure, &temperature);
1540 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1542 sstrncpy(vl.plugin, "barometer", sizeof(vl.plugin));
1543 sstrncpy(vl.plugin_instance, "bmp085", sizeof(vl.plugin_instance));
1548 /* dispatch normalized air pressure */
1549 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1550 sstrncpy(vl.type_instance, "normalized", sizeof(vl.type_instance));
1551 values[0].gauge = norm_pressure;
1552 plugin_dispatch_values(&vl);
1554 /* dispatch absolute air pressure */
1555 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1556 sstrncpy(vl.type_instance, "absolute", sizeof(vl.type_instance));
1557 values[0].gauge = pressure;
1558 plugin_dispatch_values(&vl);
1560 /* dispatch sensor temperature */
1561 sstrncpy(vl.type, "temperature", sizeof(vl.type));
1562 sstrncpy(vl.type_instance, "", sizeof(vl.type_instance));
1563 values[0].gauge = temperature;
1564 plugin_dispatch_values(&vl);
1570 * Initialization callback
1572 * Check config, initialize I2C bus access, conversion coefficients and
1576 * @return Zero when successful.
1578 static int collectd_barometer_init(void) {
1581 DEBUG("barometer: collectd_barometer_init");
1583 if (config_device == NULL) {
1584 ERROR("barometer: collectd_barometer_init I2C bus device not configured");
1588 if (config_normalize >= MSLP_INTERNATIONAL && isnan(config_altitude)) {
1589 ERROR("barometer: collectd_barometer_init no altitude configured "
1590 "for mean sea level pressure normalization.");
1594 if (config_normalize == MSLP_DEU_WETT && temp_list == NULL) {
1595 ERROR("barometer: collectd_barometer_init no temperature reference "
1596 "configured for mean sea level pressure normalization.");
1600 i2c_bus_fd = open(config_device, O_RDWR);
1601 if (i2c_bus_fd < 0) {
1602 ERROR("barometer: collectd_barometer_init problem opening I2C bus device "
1603 "\"%s\": %s (is loaded mod i2c-dev?)",
1604 config_device, sstrerror(errno, errbuf, sizeof(errbuf)));
1608 /* detect sensor type - this will also set slave address */
1609 sensor_type = detect_sensor_type();
1611 /* init correct sensor type */
1612 switch (sensor_type) {
1614 case Sensor_MPL3115: {
1615 MPL3115_adjust_oversampling();
1617 if (MPL3115_init_sensor())
1620 plugin_register_read("barometer", MPL3115_collectd_barometer_read);
1624 case Sensor_MPL115: {
1625 if (averaging_create(&pressure_averaging, config_oversample)) {
1627 "barometer: collectd_barometer_init pressure averaging init failed");
1631 if (averaging_create(&temperature_averaging, config_oversample)) {
1632 ERROR("barometer: collectd_barometer_init temperature averaging init "
1637 if (MPL115_read_coeffs() < 0)
1640 plugin_register_read("barometer", MPL115_collectd_barometer_read);
1644 case Sensor_BMP085: {
1645 BMP085_adjust_oversampling();
1647 if (BMP085_read_coeffs() < 0)
1650 plugin_register_read("barometer", BMP085_collectd_barometer_read);
1653 /* anything else -> error */
1655 ERROR("barometer: collectd_barometer_init - no supported sensor found");
1663 /* ------------------------ plugin register / entry point
1664 * ------------------------ */
1667 * Plugin "entry" - register all callback.
1670 void module_register(void) {
1671 plugin_register_config("barometer", collectd_barometer_config, config_keys,
1673 plugin_register_init("barometer", collectd_barometer_init);
1674 plugin_register_shutdown("barometer", collectd_barometer_shutdown);