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
25 #include "utils_cache.h"
31 #include <linux/i2c-dev.h>
34 /* ------------ MPL115 defines ------------ */
35 /* I2C address of the MPL115 sensor */
36 #define MPL115_I2C_ADDRESS 0x60
38 /* register addresses */
39 #define MPL115_ADDR_CONV 0x00
40 #define MPL115_ADDR_COEFFS 0x04
43 #define MPL115_NUM_CONV 4
44 #define MPL115_NUM_COEFFS 12
46 /* commands / addresses */
47 #define MPL115_CMD_CONVERT_PRESS 0x10
48 #define MPL115_CMD_CONVERT_TEMP 0x11
49 #define MPL115_CMD_CONVERT_BOTH 0x12
51 #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 (MPL3115_DR_STATUS_TDR | MPL3115_DR_STATUS_PDR | MPL3115_DR_STATUS_PTDR)
92 #define MPL3115_DR_STATUS_TOW 0x20
93 #define MPL3115_DR_STATUS_POW 0x40
94 #define MPL3115_DR_STATUS_PTOW 0x80
96 #define MPL3115_CTRL_REG1_ALT 0x80
97 #define MPL3115_CTRL_REG1_RAW 0x40
98 #define MPL3115_CTRL_REG1_OST_MASK 0x38
99 #define MPL3115_CTRL_REG1_OST_1 0x00
100 #define MPL3115_CTRL_REG1_OST_2 0x08
101 #define MPL3115_CTRL_REG1_OST_4 0x10
102 #define MPL3115_CTRL_REG1_OST_8 0x18
103 #define MPL3115_CTRL_REG1_OST_16 0x20
104 #define MPL3115_CTRL_REG1_OST_32 0x28
105 #define MPL3115_CTRL_REG1_OST_64 0x30
106 #define MPL3115_CTRL_REG1_OST_128 0x38
107 #define MPL3115_CTRL_REG1_RST 0x04
108 #define MPL3115_CTRL_REG1_OST 0x02
109 #define MPL3115_CTRL_REG1_SBYB 0x01
110 #define MPL3115_CTRL_REG1_SBYB_MASK 0xFE
112 #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
150 /* ------------ Normalization ------------ */
151 /* Mean sea level pressure normalization methods */
153 #define MSLP_INTERNATIONAL 1
154 #define MSLP_DEU_WETT 2
156 /** Temperature reference history depth for averaging. See #get_reference_temperature */
157 #define REF_TEMP_AVG_NUM 5
160 /* ------------------------------------------ */
162 /** Supported sensor types */
170 static const char *config_keys[] =
174 "PressureOffset", /**< only for MPL3115 */
175 "TemperatureOffset", /**< only for MPL3115 */
181 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
183 static char * config_device = NULL; /**< I2C bus device */
184 static int config_oversample = 1; /**< averaging window */
186 static double config_press_offset = 0.0; /**< pressure offset */
187 static double config_temp_offset = 0.0; /**< temperature offset */
189 static double config_altitude = NAN; /**< altitude */
190 static int config_normalize = 0; /**< normalization method */
192 static _Bool configured = 0; /**< the whole plugin config status */
194 static int i2c_bus_fd = -1; /**< I2C bus device FD */
196 static enum Sensor_type sensor_type = Sensor_none; /**< detected/used sensor type */
198 static __s32 mpl3115_oversample = 0; /**< MPL3115 CTRL1 oversample setting */
200 // BMP085 configuration
201 static unsigned bmp085_oversampling; /**< BMP085 oversampling (0-3) */
202 static unsigned long bmp085_timeCnvPress; /**< BMP085 conversion time for pressure in us */
203 static __u8 bmp085_cmdCnvPress; /**< BMP085 pressure conversion command */
206 /* MPL115 conversion coefficients */
207 static double mpl115_coeffA0;
208 static double mpl115_coeffB1;
209 static double mpl115_coeffB2;
210 static double mpl115_coeffC12;
211 static double mpl115_coeffC11;
212 static double mpl115_coeffC22;
214 /* BMP085 conversion coefficients */
215 static short bmp085_AC1;
216 static short bmp085_AC2;
217 static short bmp085_AC3;
218 static unsigned short bmp085_AC4;
219 static unsigned short bmp085_AC5;
220 static unsigned short bmp085_AC6;
221 static short bmp085_B1;
222 static short bmp085_B2;
223 static short bmp085_MB;
224 static short bmp085_MC;
225 static short bmp085_MD;
229 /* ------------------------ averaging ring buffer ------------------------ */
230 /* Used only for MPL115. MPL3115 supports real oversampling in the device so */
231 /* no need for any postprocessing. */
233 static _Bool avg_initialized = 0; /**< already initialized by real values */
235 typedef struct averaging_s {
236 long int * ring_buffer;
237 int ring_buffer_size;
238 long int ring_buffer_sum;
239 int ring_buffer_head;
243 static averaging_t pressure_averaging = { NULL, 0, 0L, 0 };
244 static averaging_t temperature_averaging = { NULL, 0, 0L, 0 };
248 * Create / allocate averaging buffer
250 * The buffer is initialized with zeros.
252 * @param avg pointer to ring buffer to be allocated
253 * @param size requested buffer size
255 * @return Zero when successful
257 static int averaging_create(averaging_t *avg, int size)
259 avg->ring_buffer = calloc ((size_t) size, sizeof (*avg->ring_buffer));
260 if (avg->ring_buffer == NULL)
262 ERROR ("barometer: averaging_create - ring buffer allocation of size %d failed",
267 avg->ring_buffer_size = size;
268 avg->ring_buffer_sum = 0L;
269 avg->ring_buffer_head = 0;
276 * Delete / free existing averaging buffer
278 * @param avg pointer to the ring buffer to be deleted
280 static void averaging_delete(averaging_t * avg)
282 if (avg->ring_buffer != NULL)
284 free(avg->ring_buffer);
285 avg->ring_buffer = NULL;
287 avg->ring_buffer_size = 0;
288 avg->ring_buffer_sum = 0L;
289 avg->ring_buffer_head = 0;
294 * Add new sample to the averaging buffer
296 * A new averaged value is returned. Note that till the buffer is full
297 * returned value is inaccurate as it is an average of real values and initial
300 * @param avg pointer to the ring buffer
301 * @param sample new sample value
303 * @return Averaged sample value
305 static double averaging_add_sample(averaging_t * avg, long int sample)
309 avg->ring_buffer_sum += sample - avg->ring_buffer[avg->ring_buffer_head];
310 avg->ring_buffer[avg->ring_buffer_head] = sample;
311 avg->ring_buffer_head = (avg->ring_buffer_head+1) % avg->ring_buffer_size;
312 result = (double)(avg->ring_buffer_sum) / (double)(avg->ring_buffer_size);
314 DEBUG ("barometer: averaging_add_sample - added %ld, result = %lf",
322 /* ------------------------ temperature refference ------------------------ */
325 * Linked list type of temperature sensor references
327 typedef struct temperature_list_s {
328 char * sensor_name; /**< sensor name/reference */
329 size_t num_values; /**< number of values (usually one) */
330 _Bool initialized; /**< sensor already provides data */
331 struct temperature_list_s * next; /**< next in the list */
332 } temperature_list_t;
334 static temperature_list_t * temp_list = NULL;
338 * Add new sensor to the temperature reference list
340 * @param list the list
341 * @param sensor reference name (as provided by the config file)
343 * @return Zero when successful
345 static int temp_list_add(temperature_list_t * list, const char * sensor)
347 temperature_list_t *new_temp;
349 new_temp = malloc(sizeof (*new_temp));
353 new_temp->sensor_name = strdup(sensor);
354 new_temp->initialized = 0;
355 new_temp->num_values = 0;
356 if(new_temp->sensor_name == NULL)
362 new_temp->next = temp_list;
363 temp_list = new_temp;
369 * Delete the whole temperature reference list
371 * @param list the list to be deleted
373 static void temp_list_delete(temperature_list_t ** list)
375 temperature_list_t * tmp;
377 while (*list != NULL)
380 (*list) = (*list)->next;
381 free(tmp->sensor_name);
389 * Get reference temperature value
391 * First initially uc_get_rate_by_name is tried. At the startup due to nondeterministic
392 * order the temperature may not be read yet (then it fails and first measurment gives
393 * only absolute air pressure reading which is acceptable). Once it succedes (should be
394 * second measurement at the latest) we use average of few last readings from
395 * uc_get_history_by_name. It may take few readings to start filling so again we use
396 * uc_get_rate_by_name as a fallback.
397 * The idea is to use basic "noise" filtering (history averaging) across all the values
398 * which given sensor provides (up to given depth). Then we get minimum among
401 * @param result where the result is stored. When not available NAN is stored.
403 * @return Zero when successful
405 static int get_reference_temperature(double * result)
407 temperature_list_t * list = temp_list;
409 gauge_t * values = NULL; /**< rate values */
410 size_t values_num = 0; /**< number of rate values */
413 gauge_t values_history[REF_TEMP_AVG_NUM];
415 double avg_sum; /**< Value sum for computing average */
416 int avg_num; /**< Number of values for computing average */
417 double average; /**< Resulting value average */
426 /* First time need to read current rate to learn how many values are
427 there (typically for temperature it would be just one).
428 We do not expect dynamic changing of number of temperarure values
429 in runtime yet (are there any such cases?). */
430 if(!list->initialized)
432 if(uc_get_rate_by_name(list->sensor_name,
436 DEBUG ("barometer: get_reference_temperature - rate \"%s\" not found yet",
442 DEBUG ("barometer: get_reference_temperature - initialize \"%s\", %zu vals",
446 list->initialized = 1;
447 list->num_values = values_num;
449 for(i=0; i<values_num; ++i)
451 DEBUG ("barometer: get_reference_temperature - rate %zu: %lf **",
453 if(!isnan(values[i]))
455 avg_sum += values[i];
463 /* It is OK to get here the first time as well, in the worst case
464 the history will full of NANs. */
465 if(uc_get_history_by_name(list->sensor_name,
470 ERROR ("barometer: get_reference_temperature - history \"%s\" lost",
472 list->initialized = 0;
473 list->num_values = 0;
478 for(i=0; i<REF_TEMP_AVG_NUM*list->num_values; ++i)
480 DEBUG ("barometer: get_reference_temperature - history %zu: %lf",
481 i, values_history[i]);
482 if(!isnan(values_history[i]))
484 avg_sum += values_history[i];
489 if(avg_num == 0) /* still no history? fallback to current */
491 if(uc_get_rate_by_name(list->sensor_name,
495 ERROR ("barometer: get_reference_temperature - rate \"%s\" lost",
497 list->initialized = 0;
498 list->num_values = 0;
503 for(i=0; i<values_num; ++i)
505 DEBUG ("barometer: get_reference_temperature - rate last %zu: %lf **",
507 if(!isnan(values[i]))
509 avg_sum += values[i];
519 ERROR ("barometer: get_reference_temperature - could not read \"%s\"",
521 list->initialized = 0;
522 list->num_values = 0;
526 average = avg_sum / (double) avg_num;
529 else if(*result>average)
533 } /* while sensor list */
537 ERROR("barometer: get_reference_temperature - no sensor available (yet?)");
540 DEBUG ("barometer: get_reference_temperature - temp is %lf", *result);
545 /* ------------------------ MPL115 access ------------------------ */
548 * Detect presence of a MPL115 pressure sensor.
550 * Unfortunately there seems to be no ID register so we just try to read first
551 * conversion coefficient from device at MPL115 address and hope it is really
552 * MPL115. We should use this check as the last resort (which would be the typical
553 * case anyway since MPL115 is the least accurate sensor).
554 * As a sideeffect will leave set I2C slave address.
556 * @return 1 if MPL115, 0 otherwise
558 static int MPL115_detect(void)
563 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL115_I2C_ADDRESS) < 0)
565 ERROR("barometer: MPL115_detect problem setting i2c slave address to 0x%02X: %s",
567 sstrerror (errno, errbuf, sizeof (errbuf)));
571 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL115_ADDR_COEFFS);
574 DEBUG ("barometer: MPL115_detect - positive detection");
578 DEBUG ("barometer: MPL115_detect - negative detection");
583 * Read the MPL115 sensor conversion coefficients.
585 * These are (device specific) constants so we can read them just once.
587 * @return Zero when successful
589 static int MPL115_read_coeffs(void)
591 uint8_t mpl115_coeffs[MPL115_NUM_COEFFS] = { 0 };
594 int8_t sia0MSB, sia0LSB, sib1MSB, sib1LSB, sib2MSB, sib2LSB;
595 int8_t sic12MSB, sic12LSB, sic11MSB, sic11LSB, sic22MSB, sic22LSB;
596 int16_t sia0, sib1, sib2, sic12, sic11, sic22;
600 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd,
602 STATIC_ARRAY_SIZE (mpl115_coeffs),
606 ERROR ("barometer: MPL115_read_coeffs - problem reading data: %s",
607 sstrerror (errno, errbuf, sizeof (errbuf)));
611 /* Using perhaps less elegant/efficient code, but more readable. */
612 /* a0: 16total 1sign 12int 4fract 0pad */
613 sia0MSB = mpl115_coeffs[0];
614 sia0LSB = mpl115_coeffs[1];
615 sia0 = (int16_t) sia0MSB <<8; /* s16 type, Shift to MSB */
616 sia0 += (int16_t) sia0LSB & 0x00FF; /* Add LSB to 16bit number */
617 mpl115_coeffA0 = (double) (sia0);
618 mpl115_coeffA0 /= 8.0; /* 3 fract bits */
620 /* b1: 16total 1sign 2int 13fract 0pad */
621 sib1MSB= mpl115_coeffs[2];
622 sib1LSB= mpl115_coeffs[3];
623 sib1 = sib1MSB <<8; /* Shift to MSB */
624 sib1 += sib1LSB & 0x00FF; /* Add LSB to 16bit number */
625 mpl115_coeffB1 = (double) (sib1);
626 mpl115_coeffB1 /= 8192.0; /* 13 fract */
628 /* b2: 16total 1sign 1int 14fract 0pad */
629 sib2MSB= mpl115_coeffs[4];
630 sib2LSB= mpl115_coeffs[5];
631 sib2 = sib2MSB <<8; /* Shift to MSB */
632 sib2 += sib2LSB & 0x00FF; /* Add LSB to 16bit number */
633 mpl115_coeffB2 = (double) (sib2);
634 mpl115_coeffB2 /= 16384.0; /* 14 fract */
636 /* c12: 14total 1sign 0int 13fract 9pad */
637 sic12MSB= mpl115_coeffs[6];
638 sic12LSB= mpl115_coeffs[7];
639 sic12 = sic12MSB <<8; /* Shift to MSB only by 8 for MSB */
640 sic12 += sic12LSB & 0x00FF;
641 mpl115_coeffC12 = (double) (sic12);
642 mpl115_coeffC12 /= 4.0; /* 16-14=2 */
643 mpl115_coeffC12 /= 4194304.0; /* 13+9=22 fract */
645 /* c11: 11total 1sign 0int 11fract 11pad */
646 sic11MSB= mpl115_coeffs[8];
647 sic11LSB= mpl115_coeffs[9];
648 sic11 = sic11MSB <<8; /* Shift to MSB only by 8 for MSB */
649 sic11 += sic11LSB & 0x00FF;
650 mpl115_coeffC11 = (double) (sic11);
651 mpl115_coeffC11 /= 32.0; /* 16-11=5 */
652 mpl115_coeffC11 /= 4194304.0; /* 11+11=22 fract */
654 /* c12: 11total 1sign 0int 10fract 15pad */
655 sic22MSB= mpl115_coeffs[10];
656 sic22LSB= mpl115_coeffs[11];
657 sic22 = sic22MSB <<8; /* Shift to MSB only by 8 for MSB */
658 sic22 += sic22LSB & 0x00FF;
659 mpl115_coeffC22 = (double) (sic22);
660 mpl115_coeffC22 /= 32.0; //16-11=5
661 mpl115_coeffC22 /= 33554432.0; /* 10+15=25 fract */
663 DEBUG("barometer: MPL115_read_coeffs: a0=%lf, b1=%lf, b2=%lf, c12=%lf, c11=%lf, c22=%lf",
675 * Convert raw adc values to real data using the sensor coefficients.
677 * @param adc_pressure adc pressure value to be converted
678 * @param adc_temp adc temperature value to be converted
679 * @param pressure computed real pressure
680 * @param temperature computed real temperature
682 static void MPL115_convert_adc_to_real(double adc_pressure,
685 double * temperature)
688 Pcomp = mpl115_coeffA0 + \
689 (mpl115_coeffB1 + mpl115_coeffC11*adc_pressure + mpl115_coeffC12*adc_temp) * adc_pressure + \
690 (mpl115_coeffB2 + mpl115_coeffC22*adc_temp) * adc_temp;
692 *pressure = ((1150.0-500.0) * Pcomp / 1023.0) + 500.0;
693 *temperature = (472.0 - adc_temp) / 5.35 + 25.0;
694 DEBUG ("barometer: MPL115_convert_adc_to_real - got %lf hPa, %lf C",
701 * Read sensor averegaed measurements
703 * @param pressure averaged measured pressure
704 * @param temperature averaged measured temperature
706 * @return Zero when successful
708 static int MPL115_read_averaged(double * pressure, double * temperature)
710 uint8_t mpl115_conv[MPL115_NUM_CONV] = { 0 };
714 int conv_temperature;
716 double adc_temperature;
722 /* start conversion of both temp and presure */
723 retries = MPL115_CONVERSION_RETRIES;
726 /* write 1 to start conversion */
727 res = i2c_smbus_write_byte_data (i2c_bus_fd,
728 MPL115_CMD_CONVERT_BOTH,
736 ERROR ("barometer: MPL115_read_averaged - requesting conversion: %s, " \
737 "will retry at most %d more times",
738 sstrerror (errno, errbuf, sizeof (errbuf)),
743 ERROR ("barometer: MPL115_read_averaged - requesting conversion: %s, "\
744 "too many failed retries",
745 sstrerror (errno, errbuf, sizeof (errbuf)));
750 usleep (10000); /* wait 10ms for the conversion */
752 retries=MPL115_CONVERSION_RETRIES;
755 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd,
757 STATIC_ARRAY_SIZE (mpl115_conv),
765 ERROR ("barometer: MPL115_read_averaged - reading conversion: %s, " \
766 "will retry at most %d more times",
767 sstrerror (errno, errbuf, sizeof (errbuf)),
772 ERROR ("barometer: MPL115_read_averaged - reading conversion: %s, " \
773 "too many failed retries",
774 sstrerror (errno, errbuf, sizeof (errbuf)));
779 conv_pressure = ((mpl115_conv[0] << 8) | mpl115_conv[1]) >> 6;
780 conv_temperature = ((mpl115_conv[2] << 8) | mpl115_conv[3]) >> 6;
781 DEBUG ("barometer: MPL115_read_averaged, raw pressure ADC value = %d, " \
782 "raw temperature ADC value = %d",
786 adc_pressure = averaging_add_sample (&pressure_averaging, conv_pressure);
787 adc_temperature = averaging_add_sample (&temperature_averaging, conv_temperature);
789 MPL115_convert_adc_to_real(adc_pressure, adc_temperature, pressure, temperature);
791 DEBUG ("barometer: MPL115_read_averaged - averaged ADC pressure = %lf / temperature = %lf, " \
792 "real pressure = %lf hPa / temperature = %lf C",
801 /* ------------------------ MPL3115 access ------------------------ */
804 * Detect presence of a MPL3115 pressure sensor by checking register "WHO AM I"
806 * As a sideeffect will leave set I2C slave address.
808 * @return 1 if MPL3115, 0 otherwise
810 static int MPL3115_detect(void)
815 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL3115_I2C_ADDRESS) < 0)
817 ERROR("barometer: MPL3115_detect problem setting i2c slave address to 0x%02X: %s",
819 sstrerror (errno, errbuf, sizeof (errbuf)));
823 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_WHO_AM_I);
824 if(res == MPL3115_WHO_AM_I_RESP)
826 DEBUG ("barometer: MPL3115_detect - positive detection");
830 DEBUG ("barometer: MPL3115_detect - negative detection");
835 * Adjusts oversampling to values supported by MPL3115
837 * MPL3115 supports only power of 2 in the range 1 to 128.
839 static void MPL3115_adjust_oversampling(void)
843 if(config_oversample > 100)
846 mpl3115_oversample = MPL3115_CTRL_REG1_OST_128;
848 else if(config_oversample > 48)
851 mpl3115_oversample = MPL3115_CTRL_REG1_OST_64;
853 else if(config_oversample > 24)
856 mpl3115_oversample = MPL3115_CTRL_REG1_OST_32;
858 else if(config_oversample > 12)
861 mpl3115_oversample = MPL3115_CTRL_REG1_OST_16;
863 else if(config_oversample > 6)
866 mpl3115_oversample = MPL3115_CTRL_REG1_OST_8;
868 else if(config_oversample > 3)
871 mpl3115_oversample = MPL3115_CTRL_REG1_OST_4;
873 else if(config_oversample > 1)
876 mpl3115_oversample = MPL3115_CTRL_REG1_OST_2;
881 mpl3115_oversample = MPL3115_CTRL_REG1_OST_1;
884 DEBUG("barometer: MPL3115_adjust_oversampling - correcting oversampling from %d to %d",
887 config_oversample = new_val;
891 * Read sensor averaged measurements
893 * @param pressure averaged measured pressure
894 * @param temperature averaged measured temperature
896 * @return Zero when successful
898 static int MPL3115_read(double * pressure, double * temperature)
902 __u8 data[MPL3115_NUM_CONV_VALS];
903 long int tmp_value = 0;
906 /* Set Active - activate the device from standby */
907 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1);
910 ERROR ("barometer: MPL3115_read - cannot read CTRL_REG1: %s",
911 sstrerror (errno, errbuf, sizeof (errbuf)));
915 res = i2c_smbus_write_byte_data(i2c_bus_fd,
916 MPL3115_REG_CTRL_REG1,
917 ctrl | MPL3115_CTRL_REG1_SBYB);
920 ERROR ("barometer: MPL3115_read - problem activating: %s",
921 sstrerror (errno, errbuf, sizeof (errbuf)));
925 /* base sleep is 5ms x OST */
926 usleep(5000 * config_oversample);
928 /* check the flags/status if ready */
929 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
932 ERROR ("barometer: MPL3115_read - cannot read status register: %s",
933 sstrerror (errno, errbuf, sizeof (errbuf)));
937 while ((res & MPL3115_DR_STATUS_DR) != MPL3115_DR_STATUS_DR)
939 /* try some extra sleep... */
942 /* ... and repeat the check. The conversion has to finish sooner or later. */
943 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
946 ERROR ("barometer: MPL3115_read - cannot read status register: %s",
947 sstrerror (errno, errbuf, sizeof (errbuf)));
952 /* Now read all the data in one block. There is address autoincrement. */
953 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd,
954 MPL3115_REG_OUT_P_MSB,
955 MPL3115_NUM_CONV_VALS,
959 ERROR ("barometer: MPL3115_read - cannot read data registers: %s",
960 sstrerror (errno, errbuf, sizeof (errbuf)));
964 tmp_value = (data[0] << 16) | (data[1] << 8) | data[2];
965 *pressure = ((double) tmp_value) / 4.0 / 16.0 / 100.0;
966 DEBUG ("barometer: MPL3115_read - absolute pressure = %lf hPa", *pressure);
970 data[3] = ~data[3] + 1;
971 *temperature = data[3];
972 *temperature = - *temperature;
976 *temperature = data[3];
979 *temperature += (double)(data[4]) / 256.0;
980 DEBUG ("barometer: MPL3115_read - temperature = %lf C", *temperature);
986 * Initialize MPL3115 for barometeric measurements
988 * @return 0 if successful
990 static int MPL3115_init_sensor(void)
996 /* Reset the sensor. It will reset immediately without ACKing */
997 /* the transaction, so no error handling here. */
998 i2c_smbus_write_byte_data(i2c_bus_fd,
999 MPL3115_REG_CTRL_REG1,
1000 MPL3115_CTRL_REG1_RST);
1002 /* wait some time for the reset to finish */
1005 /* now it should be in standby already so we can go and configure it */
1007 /* Set temperature offset. */
1008 /* result = ADCtemp + offset [C] */
1009 offset = (__s8) (config_temp_offset * 16.0);
1010 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_T, offset);
1013 ERROR ("barometer: MPL3115_init_sensor - problem setting temp offset: %s",
1014 sstrerror (errno, errbuf, sizeof (errbuf)));
1018 /* Set pressure offset. */
1019 /* result = ADCpress + offset [hPa] */
1020 offset = (__s8) (config_press_offset * 100.0 / 4.0);
1021 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_P, offset);
1024 ERROR ("barometer: MPL3115_init_sensor - problem setting pressure offset: %s",
1025 sstrerror (errno, errbuf, sizeof (errbuf)));
1029 /* Enable Data Flags in PT_DATA_CFG - flags on both pressure and temp */
1030 res = i2c_smbus_write_byte_data(i2c_bus_fd,
1031 MPL3115_REG_PT_DATA_CFG,
1032 MPL3115_PT_DATA_DREM \
1033 | MPL3115_PT_DATA_PDEF \
1034 | MPL3115_PT_DATA_TDEF);
1037 ERROR ("barometer: MPL3115_init_sensor - problem setting PT_DATA_CFG: %s",
1038 sstrerror (errno, errbuf, sizeof (errbuf)));
1042 /* Set to barometer with an OSR */
1043 res = i2c_smbus_write_byte_data(i2c_bus_fd,
1044 MPL3115_REG_CTRL_REG1,
1045 mpl3115_oversample);
1048 ERROR ("barometer: MPL3115_init_sensor - problem configuring CTRL_REG1: %s",
1049 sstrerror (errno, errbuf, sizeof (errbuf)));
1056 /* ------------------------ BMP085 access ------------------------ */
1059 * Detect presence of a BMP085 pressure sensor by checking its ID register
1061 * As a sideeffect will leave set I2C slave address.
1063 * @return 1 if BMP085, 0 otherwise
1065 static int BMP085_detect(void)
1070 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, BMP085_I2C_ADDRESS) < 0)
1072 ERROR("barometer: BMP085_detect - problem setting i2c slave address to 0x%02X: %s",
1074 sstrerror (errno, errbuf, sizeof (errbuf)));
1078 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_ID_REG);
1079 if(res == BMP085_CHIP_ID)
1081 DEBUG ("barometer: BMP085_detect - positive detection");
1084 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_VERSION );
1087 ERROR("barometer: BMP085_detect - problem checking chip version: %s",
1088 sstrerror (errno, errbuf, sizeof (errbuf)));
1091 DEBUG ("barometer: BMP085_detect - chip version ML:0x%02X AL:0x%02X",
1097 DEBUG ("barometer: BMP085_detect - negative detection");
1103 * Adjusts oversampling settings to values supported by BMP085
1105 * BMP085 supports only 1,2,4 or 8 samples.
1107 static void BMP085_adjust_oversampling(void)
1111 if( config_oversample > 6 ) /* 8 */
1114 bmp085_oversampling = 3;
1115 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_3;
1116 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_3;
1118 else if( config_oversample > 3 ) /* 4 */
1121 bmp085_oversampling = 2;
1122 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_2;
1123 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_2;
1125 else if( config_oversample > 1 ) /* 2 */
1128 bmp085_oversampling = 1;
1129 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_1;
1130 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_1;
1135 bmp085_oversampling = 0;
1136 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_0;
1137 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_0;
1140 DEBUG("barometer: BMP085_adjust_oversampling - correcting oversampling from %d to %d",
1143 config_oversample = new_val;
1148 * Read the BMP085 sensor conversion coefficients.
1150 * These are (device specific) constants so we can read them just once.
1152 * @return Zero when successful
1154 static int BMP085_read_coeffs(void)
1157 __u8 coeffs[BMP085_NUM_COEFFS];
1160 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd,
1166 ERROR ("barometer: BMP085_read_coeffs - problem reading data: %s",
1167 sstrerror (errno, errbuf, sizeof (errbuf)));
1171 bmp085_AC1 = ((int16_t) coeffs[0] <<8) | (int16_t) coeffs[1];
1172 bmp085_AC2 = ((int16_t) coeffs[2] <<8) | (int16_t) coeffs[3];
1173 bmp085_AC3 = ((int16_t) coeffs[4] <<8) | (int16_t) coeffs[5];
1174 bmp085_AC4 = ((uint16_t) coeffs[6] <<8) | (uint16_t) coeffs[7];
1175 bmp085_AC5 = ((uint16_t) coeffs[8] <<8) | (uint16_t) coeffs[9];
1176 bmp085_AC6 = ((uint16_t) coeffs[10] <<8) | (uint16_t) coeffs[11];
1177 bmp085_B1 = ((int16_t) coeffs[12] <<8) | (int16_t) coeffs[13];
1178 bmp085_B2 = ((int16_t) coeffs[14] <<8) | (int16_t) coeffs[15];
1179 bmp085_MB = ((int16_t) coeffs[16] <<8) | (int16_t) coeffs[17];
1180 bmp085_MC = ((int16_t) coeffs[18] <<8) | (int16_t) coeffs[19];
1181 bmp085_MD = ((int16_t) coeffs[20] <<8) | (int16_t) coeffs[21];
1183 DEBUG("barometer: BMP085_read_coeffs - AC1=%d, AC2=%d, AC3=%d, AC4=%u,"\
1184 " AC5=%u, AC6=%u, B1=%d, B2=%d, MB=%d, MC=%d, MD=%d",
1202 * Convert raw BMP085 adc values to real data using the sensor coefficients.
1204 * @param adc_pressure adc pressure value to be converted
1205 * @param adc_temp adc temperature value to be converted
1206 * @param pressure computed real pressure
1207 * @param temperature computed real temperature
1209 static void BMP085_convert_adc_to_real(long adc_pressure,
1210 long adc_temperature,
1212 double * temperature)
1217 unsigned long B4, B7;
1223 /* calculate real temperature */
1224 X1 = ( (adc_temperature - bmp085_AC6) * bmp085_AC5) >> 15;
1225 X2 = (bmp085_MC << 11) / (X1 + bmp085_MD);
1230 *temperature = (double)T * 0.1;
1232 /* calculate real pressure */
1233 /* in general X1, X2, X3 are recycled while values of B3, B4, B5, B6 are kept */
1237 X1 = ((bmp085_B2 * ((B6 * B6)>>12)) >> 11 );
1238 X2 = (((long)bmp085_AC2 * B6) >> 11);
1240 B3 = (((((long)bmp085_AC1 * 4) + X3) << bmp085_oversampling) + 2) >> 2;
1243 X1 = (((long)bmp085_AC3*B6) >> 13);
1244 X2 = (bmp085_B1*((B6*B6) >> 12) ) >> 16;
1245 X3 = ((X1 + X2) + 2 ) >> 2;
1246 B4 = ((long)bmp085_AC4* (unsigned long)(X3 + 32768)) >> 15;
1249 B7 = (unsigned long)(adc_pressure - B3)*(50000>>bmp085_oversampling);
1250 if( B7 < 0x80000000 )
1258 X1 = (P >> 8) * (P >> 8);
1259 X1 = (X1 * 3038) >> 16;
1260 X2 = ((-7357) * P) >> 16;
1261 P = P + ( ( X1 + X2 + 3791 ) >> 4);
1263 *pressure = P / 100.0; // in [hPa]
1264 DEBUG ("barometer: BMP085_convert_adc_to_real - got %lf hPa, %lf C",
1271 * Read compensated sensor measurements
1273 * @param pressure averaged measured pressure
1274 * @param temperature averaged measured temperature
1276 * @return Zero when successful
1278 static int BMP085_read(double * pressure, double * temperature)
1284 long adc_temperature;
1288 /* start conversion of temperature */
1289 res = i2c_smbus_write_byte_data( i2c_bus_fd,
1290 BMP085_ADDR_CTRL_REG,
1291 BMP085_CMD_CONVERT_TEMP );
1294 ERROR ("barometer: BMP085_read - problem requesting temperature conversion: %s",
1295 sstrerror (errno, errbuf, sizeof (errbuf)));
1299 usleep(BMP085_TIME_CNV_TEMP); /* wait for the conversion */
1301 res = i2c_smbus_read_i2c_block_data( i2c_bus_fd,
1307 ERROR ("barometer: BMP085_read - problem reading temperature data: %s",
1308 sstrerror (errno, errbuf, sizeof (errbuf)));
1312 adc_temperature = ( (unsigned short)measBuff[0] << 8 ) + measBuff[1];
1316 res = i2c_smbus_write_byte_data( i2c_bus_fd,
1317 BMP085_ADDR_CTRL_REG,
1318 bmp085_cmdCnvPress );
1321 ERROR ("barometer: BMP085_read - problem requesting pressure conversion: %s",
1322 sstrerror (errno, errbuf, sizeof (errbuf)));
1326 usleep(bmp085_timeCnvPress); /* wait for the conversion */
1328 res = i2c_smbus_read_i2c_block_data( i2c_bus_fd,
1334 ERROR ("barometer: BMP085_read - problem reading pressure data: %s",
1335 sstrerror (errno, errbuf, sizeof (errbuf)));
1339 adc_pressure = (long)((((ulong)measBuff[0]<<16) | ((ulong)measBuff[1]<<8) | (ulong)measBuff[2] ) >> (8 - bmp085_oversampling));
1342 DEBUG ("barometer: BMP085_read - raw pressure ADC value = %ld, " \
1343 "raw temperature ADC value = %ld",
1347 BMP085_convert_adc_to_real(adc_pressure, adc_temperature, pressure, temperature);
1354 /* ------------------------ Sensor detection ------------------------ */
1356 * Detect presence of a supported sensor.
1358 * As a sideeffect will leave set I2C slave address.
1359 * The detection is done in the order BMP085, MPL3115, MPL115 and stops after
1360 * first sensor beeing found.
1362 * @return detected sensor type
1364 static enum Sensor_type detect_sensor_type(void)
1367 return Sensor_BMP085;
1369 else if(MPL3115_detect())
1370 return Sensor_MPL3115;
1372 else if(MPL115_detect())
1373 return Sensor_MPL115;
1378 /* ------------------------ Common functionality ------------------------ */
1381 * Convert absolute pressure (in hPa) to mean sea level pressure
1383 * Implemented methods are:
1384 * - MSLP_NONE - no converions, returns absolute pressure
1386 * - MSLP_INTERNATIONAL - see http://en.wikipedia.org/wiki/Atmospheric_pressure#Altitude_atmospheric_pressure_variation
1387 * Requires #config_altitude
1389 * - MSLP_DEU_WETT - formula as recommended by the Deutsche Wetterdienst. See
1390 * http://de.wikipedia.org/wiki/Barometrische_H%C3%B6henformel#Theorie
1391 * Requires both #config_altitude and temperature reference(s).
1393 * @param abs_pressure absloute pressure to be converted
1395 * @return mean sea level pressure if successful, NAN otherwise
1397 static double abs_to_mean_sea_level_pressure(double abs_pressure)
1403 if (config_normalize >= MSLP_DEU_WETT)
1405 result = get_reference_temperature(&temp);
1412 switch(config_normalize)
1415 mean = abs_pressure;
1418 case MSLP_INTERNATIONAL:
1419 mean = abs_pressure / \
1420 pow(1.0 - 0.0065*config_altitude/288.15, 9.80665*0.0289644/(8.31447*0.0065));
1425 double E; /* humidity */
1428 E = 5.6402 * (-0.0916 + exp(0.06*temp) );
1430 E = 18.2194 * (1.0463 - exp(-0.0666*temp) );
1431 x = 9.80665 / (287.05 * (temp+273.15 + 0.12*E + 0.0065*config_altitude/2)) * config_altitude;
1432 mean = abs_pressure * exp(x);
1437 ERROR ("barometer: abs_to_mean_sea_level_pressure: wrong conversion method %d",
1439 mean = abs_pressure;
1443 DEBUG ("barometer: abs_to_mean_sea_level_pressure: absPressure = %lf hPa, method = %d, meanPressure = %lf hPa",
1451 /* ------------------------ main plugin callbacks ------------------------ */
1454 * Main plugin configuration callback (using simple config)
1456 * @param key configuration key we should process
1457 * @param value configuration value we should process
1459 * @return Zero when successful.
1461 static int collectd_barometer_config (const char *key, const char *value)
1463 DEBUG("barometer: collectd_barometer_config");
1465 if (strcasecmp (key, "Device") == 0)
1467 sfree (config_device);
1468 config_device = strdup (value);
1470 else if (strcasecmp (key, "Oversampling") == 0)
1472 int oversampling_tmp = atoi (value);
1473 if (oversampling_tmp < 1 || oversampling_tmp > 1024)
1475 WARNING ("barometer: collectd_barometer_config: invalid oversampling: %d." \
1476 " Allowed values are 1 to 1024 (for MPL115) or 1 to 128 (for MPL3115) or 1 to 8 (for BMP085).",
1480 config_oversample = oversampling_tmp;
1482 else if (strcasecmp (key, "Altitude") == 0)
1484 config_altitude = atof (value);
1486 else if (strcasecmp (key, "Normalization") == 0)
1488 int normalize_tmp = atoi (value);
1489 if (normalize_tmp < 0 || normalize_tmp > 2)
1491 WARNING ("barometer: collectd_barometer_config: invalid normalization: %d",
1495 config_normalize = normalize_tmp;
1497 else if (strcasecmp (key, "TemperatureSensor") == 0)
1499 if(temp_list_add(temp_list, value))
1504 else if (strcasecmp (key, "PressureOffset") == 0)
1506 config_press_offset = atof(value);
1508 else if (strcasecmp (key, "TemperatureOffset") == 0)
1510 config_temp_offset = atof(value);
1522 * Shutdown callback.
1524 * Close I2C and delete all the buffers.
1526 * @return Zero when successful (at the moment the only possible outcome)
1528 static int collectd_barometer_shutdown(void)
1530 DEBUG ("barometer: collectd_barometer_shutdown");
1532 if(sensor_type == Sensor_MPL115)
1534 averaging_delete (&pressure_averaging);
1535 averaging_delete (&temperature_averaging);
1537 temp_list_delete(&temp_list);
1544 sfree (config_device);
1552 * Plugin read callback for MPL115.
1554 * Dispatching will create values:
1555 * - <hostname>/barometer-mpl115/pressure-normalized
1556 * - <hostname>/barometer-mpl115/pressure-absolute
1557 * - <hostname>/barometer-mpl115/temperature
1559 * @return Zero when successful.
1561 static int MPL115_collectd_barometer_read (void)
1565 double pressure = 0.0;
1566 double temperature = 0.0;
1567 double norm_pressure = 0.0;
1569 value_list_t vl = VALUE_LIST_INIT;
1572 DEBUG("barometer: MPL115_collectd_barometer_read");
1579 /* Rather than delaying init, we will intitialize during first read. This
1580 way at least we have a better chance to have the reference temperature
1581 already available. */
1582 if(!avg_initialized)
1585 for(i=0; i<config_oversample-1; ++i)
1587 result = MPL115_read_averaged(&pressure, &temperature);
1590 ERROR ("barometer: MPL115_collectd_barometer_read - mpl115 read, ignored during init");
1592 DEBUG("barometer: MPL115_collectd_barometer_read - init %d / %d", i+1, config_oversample-1);
1595 avg_initialized = 1;
1598 result = MPL115_read_averaged(&pressure, &temperature);
1602 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1604 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
1605 sstrncpy (vl.plugin, "barometer", sizeof (vl.plugin));
1606 sstrncpy (vl.plugin_instance, "mpl115", sizeof (vl.plugin_instance));
1611 /* dispatch normalized air pressure */
1612 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1613 sstrncpy (vl.type_instance, "normalized", sizeof (vl.type_instance));
1614 values[0].gauge = norm_pressure;
1615 plugin_dispatch_values (&vl);
1617 /* dispatch absolute air pressure */
1618 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1619 sstrncpy (vl.type_instance, "absolute", sizeof (vl.type_instance));
1620 values[0].gauge = pressure;
1621 plugin_dispatch_values (&vl);
1623 /* dispatch sensor temperature */
1624 sstrncpy (vl.type, "temperature", sizeof (vl.type));
1625 sstrncpy (vl.type_instance, "", sizeof (vl.type_instance));
1626 values[0].gauge = temperature;
1627 plugin_dispatch_values (&vl);
1634 * Plugin read callback for MPL3115.
1636 * Dispatching will create values:
1637 * - <hostname>/barometer-mpl3115/pressure-normalized
1638 * - <hostname>/barometer-mpl3115/pressure-absolute
1639 * - <hostname>/barometer-mpl3115/temperature
1641 * @return Zero when successful.
1643 static int MPL3115_collectd_barometer_read (void)
1647 double pressure = 0.0;
1648 double temperature = 0.0;
1649 double norm_pressure = 0.0;
1651 value_list_t vl = VALUE_LIST_INIT;
1654 DEBUG("barometer: MPL3115_collectd_barometer_read");
1661 result = MPL3115_read(&pressure, &temperature);
1665 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1667 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
1668 sstrncpy (vl.plugin, "barometer", sizeof (vl.plugin));
1669 sstrncpy (vl.plugin_instance, "mpl3115", sizeof (vl.plugin_instance));
1674 /* dispatch normalized air pressure */
1675 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1676 sstrncpy (vl.type_instance, "normalized", sizeof (vl.type_instance));
1677 values[0].gauge = norm_pressure;
1678 plugin_dispatch_values (&vl);
1680 /* dispatch absolute air pressure */
1681 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1682 sstrncpy (vl.type_instance, "absolute", sizeof (vl.type_instance));
1683 values[0].gauge = pressure;
1684 plugin_dispatch_values (&vl);
1686 /* dispatch sensor temperature */
1687 sstrncpy (vl.type, "temperature", sizeof (vl.type));
1688 sstrncpy (vl.type_instance, "", sizeof (vl.type_instance));
1689 values[0].gauge = temperature;
1690 plugin_dispatch_values (&vl);
1697 * Plugin read callback for BMP085.
1699 * Dispatching will create values:
1700 * - <hostname>/barometer-bmp085/pressure-normalized
1701 * - <hostname>/barometer-bmp085/pressure-absolute
1702 * - <hostname>/barometer-bmp085/temperature
1704 * @return Zero when successful.
1706 static int BMP085_collectd_barometer_read (void)
1710 double pressure = 0.0;
1711 double temperature = 0.0;
1712 double norm_pressure = 0.0;
1714 value_list_t vl = VALUE_LIST_INIT;
1717 DEBUG("barometer: BMP085_collectd_barometer_read");
1724 result = BMP085_read(&pressure, &temperature);
1728 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1730 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
1731 sstrncpy (vl.plugin, "barometer", sizeof (vl.plugin));
1732 sstrncpy (vl.plugin_instance, "bmp085", sizeof (vl.plugin_instance));
1737 /* dispatch normalized air pressure */
1738 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1739 sstrncpy (vl.type_instance, "normalized", sizeof (vl.type_instance));
1740 values[0].gauge = norm_pressure;
1741 plugin_dispatch_values (&vl);
1743 /* dispatch absolute air pressure */
1744 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1745 sstrncpy (vl.type_instance, "absolute", sizeof (vl.type_instance));
1746 values[0].gauge = pressure;
1747 plugin_dispatch_values (&vl);
1749 /* dispatch sensor temperature */
1750 sstrncpy (vl.type, "temperature", sizeof (vl.type));
1751 sstrncpy (vl.type_instance, "", sizeof (vl.type_instance));
1752 values[0].gauge = temperature;
1753 plugin_dispatch_values (&vl);
1760 * Initialization callback
1762 * Check config, initialize I2C bus access, conversion coefficients and averaging
1765 * @return Zero when successful.
1767 static int collectd_barometer_init (void)
1771 DEBUG ("barometer: collectd_barometer_init");
1773 if (config_device == NULL)
1775 ERROR("barometer: collectd_barometer_init I2C bus device not configured");
1779 if (config_normalize >= MSLP_INTERNATIONAL && isnan(config_altitude))
1781 ERROR("barometer: collectd_barometer_init no altitude configured " \
1782 "for mean sea level pressure normalization.");
1786 if (config_normalize == MSLP_DEU_WETT
1790 ERROR("barometer: collectd_barometer_init no temperature reference "\
1791 "configured for mean sea level pressure normalization.");
1796 i2c_bus_fd = open(config_device, O_RDWR);
1799 ERROR ("barometer: collectd_barometer_init problem opening I2C bus device \"%s\": %s (is loaded mod i2c-dev?)",
1801 sstrerror (errno, errbuf, sizeof (errbuf)));
1805 /* detect sensor type - this will also set slave address */
1806 sensor_type = detect_sensor_type();
1808 /* init correct sensor type */
1812 case Sensor_MPL3115:
1814 MPL3115_adjust_oversampling();
1816 if(MPL3115_init_sensor())
1819 plugin_register_read ("barometer", MPL3115_collectd_barometer_read);
1826 if (averaging_create (&pressure_averaging, config_oversample))
1828 ERROR("barometer: collectd_barometer_init pressure averaging init failed");
1832 if (averaging_create (&temperature_averaging, config_oversample))
1834 ERROR("barometer: collectd_barometer_init temperature averaging init failed");
1838 if (MPL115_read_coeffs() < 0)
1841 plugin_register_read ("barometer", MPL115_collectd_barometer_read);
1848 BMP085_adjust_oversampling();
1850 if (BMP085_read_coeffs() < 0)
1853 plugin_register_read ("barometer", BMP085_collectd_barometer_read);
1857 /* anything else -> error */
1859 ERROR("barometer: collectd_barometer_init - no supported sensor found");
1868 /* ------------------------ plugin register / entry point ------------------------ */
1871 * Plugin "entry" - register all callback.
1874 void module_register (void)
1876 plugin_register_config ("barometer",
1877 collectd_barometer_config,
1880 plugin_register_init ("barometer", collectd_barometer_init);
1881 plugin_register_shutdown ("barometer", collectd_barometer_shutdown);