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
24 #include "utils_cache.h"
30 #include <linux/i2c-dev.h>
33 /* ------------ MPL115 defines ------------ */
34 /* I2C address of the MPL115 sensor */
35 #define MPL115_I2C_ADDRESS 0x60
37 /* register addresses */
38 #define MPL115_ADDR_CONV 0x00
39 #define MPL115_ADDR_COEFFS 0x04
42 #define MPL115_NUM_CONV 4
43 #define MPL115_NUM_COEFFS 12
45 /* commands / addresses */
46 #define MPL115_CMD_CONVERT_PRESS 0x10
47 #define MPL115_CMD_CONVERT_TEMP 0x11
48 #define MPL115_CMD_CONVERT_BOTH 0x12
50 #define MPL115_CONVERSION_RETRIES 5
53 /* ------------ MPL3115 defines ------------ */
54 /* MPL3115 I2C address */
55 #define MPL3115_I2C_ADDRESS 0x60
57 /* register addresses (only the interesting ones) */
58 #define MPL3115_REG_STATUS 0x00
59 #define MPL3115_REG_OUT_P_MSB 0x01
60 #define MPL3115_REG_OUT_P_CSB 0x02
61 #define MPL3115_REG_OUT_P_LSB 0x03
62 #define MPL3115_REG_OUT_T_MSB 0x04
63 #define MPL3115_REG_OUT_T_LSB 0x05
64 #define MPL3115_REG_DR_STATUS 0x06
65 #define MPL3115_REG_WHO_AM_I 0x0C
66 #define MPL3115_REG_SYSMOD 0x11
67 #define MPL3115_REG_PT_DATA_CFG 0x13
68 #define MPL3115_REG_BAR_IN_MSB 0x14
69 #define MPL3115_REG_BAR_IN_LSB 0x15
70 #define MPL3115_REG_CTRL_REG1 0x26
71 #define MPL3115_REG_CTRL_REG2 0x27
72 #define MPL3115_REG_CTRL_REG3 0x28
73 #define MPL3115_REG_CTRL_REG4 0x29
74 #define MPL3115_REG_CTRL_REG5 0x2A
75 #define MPL3115_REG_OFF_P 0x2B
76 #define MPL3115_REG_OFF_T 0x2C
77 #define MPL3115_REG_OFF_H 0x2D
79 /* Register values, masks */
80 #define MPL3115_WHO_AM_I_RESP 0xC4
82 #define MPL3115_PT_DATA_DREM 0x04
83 #define MPL3115_PT_DATA_PDEF 0x02
84 #define MPL3115_PT_DATA_TDEF 0x01
86 #define MPL3115_DR_STATUS_TDR 0x02
87 #define MPL3115_DR_STATUS_PDR 0x04
88 #define MPL3115_DR_STATUS_PTDR 0x08
89 #define MPL3115_DR_STATUS_DR (MPL3115_DR_STATUS_TDR | MPL3115_DR_STATUS_PDR | MPL3115_DR_STATUS_PTDR)
91 #define MPL3115_DR_STATUS_TOW 0x20
92 #define MPL3115_DR_STATUS_POW 0x40
93 #define MPL3115_DR_STATUS_PTOW 0x80
95 #define MPL3115_CTRL_REG1_ALT 0x80
96 #define MPL3115_CTRL_REG1_RAW 0x40
97 #define MPL3115_CTRL_REG1_OST_MASK 0x38
98 #define MPL3115_CTRL_REG1_OST_1 0x00
99 #define MPL3115_CTRL_REG1_OST_2 0x08
100 #define MPL3115_CTRL_REG1_OST_4 0x10
101 #define MPL3115_CTRL_REG1_OST_8 0x18
102 #define MPL3115_CTRL_REG1_OST_16 0x20
103 #define MPL3115_CTRL_REG1_OST_32 0x28
104 #define MPL3115_CTRL_REG1_OST_64 0x30
105 #define MPL3115_CTRL_REG1_OST_128 0x38
106 #define MPL3115_CTRL_REG1_RST 0x04
107 #define MPL3115_CTRL_REG1_OST 0x02
108 #define MPL3115_CTRL_REG1_SBYB 0x01
109 #define MPL3115_CTRL_REG1_SBYB_MASK 0xFE
111 #define MPL3115_NUM_CONV_VALS 5
114 /* ------------ BMP085 defines ------------ */
115 /* I2C address of the BMP085 sensor */
116 #define BMP085_I2C_ADDRESS 0x77
118 /* register addresses */
119 #define BMP085_ADDR_ID_REG 0xD0
120 #define BMP085_ADDR_VERSION 0xD1
122 #define BMP085_ADDR_CONV 0xF6
124 #define BMP085_ADDR_CTRL_REG 0xF4
125 #define BMP085_ADDR_COEFFS 0xAA
128 #define BMP085_NUM_COEFFS 22
130 /* commands, values */
131 #define BMP085_CHIP_ID 0x55
133 #define BMP085_CMD_CONVERT_TEMP 0x2E
135 #define BMP085_CMD_CONVERT_PRESS_0 0x34
136 #define BMP085_CMD_CONVERT_PRESS_1 0x74
137 #define BMP085_CMD_CONVERT_PRESS_2 0xB4
138 #define BMP085_CMD_CONVERT_PRESS_3 0xF4
141 #define BMP085_TIME_CNV_TEMP 4500
143 #define BMP085_TIME_CNV_PRESS_0 4500
144 #define BMP085_TIME_CNV_PRESS_1 7500
145 #define BMP085_TIME_CNV_PRESS_2 13500
146 #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 #get_reference_temperature */
156 #define REF_TEMP_AVG_NUM 5
159 /* ------------------------------------------ */
161 /** Supported sensor types */
169 static const char *config_keys[] =
173 "PressureOffset", /**< only for MPL3115 */
174 "TemperatureOffset", /**< only for MPL3115 */
180 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
182 static char * config_device = NULL; /**< I2C bus device */
183 static int config_oversample = 1; /**< averaging window */
185 static double config_press_offset = 0.0; /**< pressure offset */
186 static double config_temp_offset = 0.0; /**< temperature offset */
188 static double config_altitude = NAN; /**< altitude */
189 static int config_normalize = 0; /**< normalization method */
191 static _Bool configured = 0; /**< the whole plugin config status */
193 static int i2c_bus_fd = -1; /**< I2C bus device FD */
195 static enum Sensor_type sensor_type = Sensor_none; /**< detected/used sensor type */
197 static __s32 mpl3115_oversample = 0; /**< MPL3115 CTRL1 oversample setting */
199 // BMP085 configuration
200 static unsigned bmp085_oversampling; /**< BMP085 oversampling (0-3) */
201 static unsigned long bmp085_timeCnvPress; /**< BMP085 conversion time for pressure in us */
202 static __u8 bmp085_cmdCnvPress; /**< BMP085 pressure conversion command */
205 /* MPL115 conversion coefficients */
206 static double mpl115_coeffA0;
207 static double mpl115_coeffB1;
208 static double mpl115_coeffB2;
209 static double mpl115_coeffC12;
210 static double mpl115_coeffC11;
211 static double mpl115_coeffC22;
213 /* BMP085 conversion coefficients */
214 static short bmp085_AC1;
215 static short bmp085_AC2;
216 static short bmp085_AC3;
217 static unsigned short bmp085_AC4;
218 static unsigned short bmp085_AC5;
219 static unsigned short bmp085_AC6;
220 static short bmp085_B1;
221 static short bmp085_B2;
222 static short bmp085_MB;
223 static short bmp085_MC;
224 static short bmp085_MD;
228 /* ------------------------ averaging ring buffer ------------------------ */
229 /* Used only for MPL115. MPL3115 supports real oversampling in the device so */
230 /* no need for any postprocessing. */
232 static _Bool avg_initialized = 0; /**< already initialized by real values */
234 typedef struct averaging_s {
235 long int * ring_buffer;
236 int ring_buffer_size;
237 long int ring_buffer_sum;
238 int ring_buffer_head;
242 static averaging_t pressure_averaging = { NULL, 0, 0L, 0 };
243 static averaging_t temperature_averaging = { NULL, 0, 0L, 0 };
247 * Create / allocate averaging buffer
249 * The buffer is initialized with zeros.
251 * @param avg pointer to ring buffer to be allocated
252 * @param size requested buffer size
254 * @return Zero when successful
256 static int averaging_create(averaging_t * avg, int size)
260 avg->ring_buffer = (long int *) malloc(size * sizeof(*avg));
261 if (avg->ring_buffer == NULL)
263 ERROR ("barometer: averaging_create - ring buffer allocation of size %d failed",
268 for (a=0; a<size; ++a)
270 avg->ring_buffer[a] = 0L;
273 avg->ring_buffer_size = size;
274 avg->ring_buffer_sum = 0L;
275 avg->ring_buffer_head = 0;
282 * Delete / free existing averaging buffer
284 * @param avg pointer to the ring buffer to be deleted
286 static void averaging_delete(averaging_t * avg)
288 if (avg->ring_buffer != NULL)
290 free(avg->ring_buffer);
291 avg->ring_buffer = NULL;
293 avg->ring_buffer_size = 0;
294 avg->ring_buffer_sum = 0L;
295 avg->ring_buffer_head = 0;
300 * Add new sample to the averaging buffer
302 * A new averaged value is returned. Note that till the buffer is full
303 * returned value is inaccurate as it is an average of real values and initial
306 * @param avg pointer to the ring buffer
307 * @param sample new sample value
309 * @return Averaged sample value
311 static double averaging_add_sample(averaging_t * avg, long int sample)
315 avg->ring_buffer_sum += sample - avg->ring_buffer[avg->ring_buffer_head];
316 avg->ring_buffer[avg->ring_buffer_head] = sample;
317 avg->ring_buffer_head = (avg->ring_buffer_head+1) % avg->ring_buffer_size;
318 result = (double)(avg->ring_buffer_sum) / (double)(avg->ring_buffer_size);
320 DEBUG ("barometer: averaging_add_sample - added %ld, result = %lf",
328 /* ------------------------ temperature refference ------------------------ */
331 * Linked list type of temperature sensor references
333 typedef struct temperature_list_s {
334 char * sensor_name; /**< sensor name/reference */
335 size_t num_values; /**< number of values (usually one) */
336 _Bool initialized; /**< sensor already provides data */
337 struct temperature_list_s * next; /**< next in the list */
338 } temperature_list_t;
340 static temperature_list_t * temp_list = NULL;
344 * Add new sensor to the temperature reference list
346 * @param list the list
347 * @param sensor reference name (as provided by the config file)
349 * @return Zero when successful
351 static int temp_list_add(temperature_list_t * list, const char * sensor)
353 temperature_list_t * new_temp;
355 new_temp = (temperature_list_t *) malloc(sizeof(*new_temp));
359 new_temp->sensor_name = strdup(sensor);
360 new_temp->initialized = 0;
361 new_temp->num_values = 0;
362 if(new_temp->sensor_name == NULL)
368 new_temp->next = temp_list;
369 temp_list = new_temp;
375 * Delete the whole temperature reference list
377 * @param list the list to be deleted
379 static void temp_list_delete(temperature_list_t ** list)
381 temperature_list_t * tmp;
383 while (*list != NULL)
386 (*list) = (*list)->next;
387 free(tmp->sensor_name);
395 * Get reference temperature value
397 * First initially uc_get_rate_by_name is tried. At the startup due to nondeterministic
398 * order the temperature may not be read yet (then it fails and first measurment gives
399 * only absolute air pressure reading which is acceptable). Once it succedes (should be
400 * second measurement at the latest) we use average of few last readings from
401 * uc_get_history_by_name. It may take few readings to start filling so again we use
402 * uc_get_rate_by_name as a fallback.
403 * The idea is to use basic "noise" filtering (history averaging) across all the values
404 * which given sensor provides (up to given depth). Then we get minimum among
407 * @param result where the result is stored. When not available NAN is stored.
409 * @return Zero when successful
411 static int get_reference_temperature(double * result)
413 temperature_list_t * list = temp_list;
415 gauge_t * values = NULL; /**< rate values */
416 size_t values_num = 0; /**< number of rate values */
419 gauge_t values_history[REF_TEMP_AVG_NUM];
421 double avg_sum; /**< Value sum for computing average */
422 int avg_num; /**< Number of values for computing average */
423 double average; /**< Resulting value average */
432 /* First time need to read current rate to learn how many values are
433 there (typically for temperature it would be just one).
434 We do not expect dynamic changing of number of temperarure values
435 in runtime yet (are there any such cases?). */
436 if(!list->initialized)
438 if(uc_get_rate_by_name(list->sensor_name,
442 DEBUG ("barometer: get_reference_temperature - rate \"%s\" not found yet",
448 DEBUG ("barometer: get_reference_temperature - initialize \"%s\", %zu vals",
452 list->initialized = 1;
453 list->num_values = values_num;
455 for(i=0; i<values_num; ++i)
457 DEBUG ("barometer: get_reference_temperature - rate %d: %lf **",
460 if(!isnan(values[i]))
462 avg_sum += values[i];
470 /* It is OK to get here the first time as well, in the worst case
471 the history will full of NANs. */
472 if(uc_get_history_by_name(list->sensor_name,
477 ERROR ("barometer: get_reference_temperature - history \"%s\" lost",
479 list->initialized = 0;
480 list->num_values = 0;
485 for(i=0; i<REF_TEMP_AVG_NUM*list->num_values; ++i)
487 DEBUG ("barometer: get_reference_temperature - history %d: %lf",
490 if(!isnan(values_history[i]))
492 avg_sum += values_history[i];
497 if(avg_num == 0) /* still no history? fallback to current */
499 if(uc_get_rate_by_name(list->sensor_name,
503 ERROR ("barometer: get_reference_temperature - rate \"%s\" lost",
505 list->initialized = 0;
506 list->num_values = 0;
511 for(i=0; i<values_num; ++i)
513 DEBUG ("barometer: get_reference_temperature - rate last %d: %lf **",
516 if(!isnan(values[i]))
518 avg_sum += values[i];
528 ERROR ("barometer: get_reference_temperature - could not read \"%s\"",
530 list->initialized = 0;
531 list->num_values = 0;
535 average = avg_sum / (double) avg_num;
538 else if(*result>average)
542 } /* while sensor list */
546 ERROR("barometer: get_reference_temperature - no sensor available (yet?)");
549 DEBUG ("barometer: get_reference_temperature - temp is %lf", *result);
554 /* ------------------------ MPL115 access ------------------------ */
557 * Detect presence of a MPL115 pressure sensor.
559 * Unfortunately there seems to be no ID register so we just try to read first
560 * conversion coefficient from device at MPL115 address and hope it is really
561 * MPL115. We should use this check as the last resort (which would be the typical
562 * case anyway since MPL115 is the least accurate sensor).
563 * As a sideeffect will leave set I2C slave address.
565 * @return 1 if MPL115, 0 otherwise
567 static int MPL115_detect(void)
572 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL115_I2C_ADDRESS) < 0)
574 ERROR("barometer: MPL115_detect problem setting i2c slave address to 0x%02X: %s",
576 sstrerror (errno, errbuf, sizeof (errbuf)));
580 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL115_ADDR_COEFFS);
583 DEBUG ("barometer: MPL115_detect - positive detection");
587 DEBUG ("barometer: MPL115_detect - negative detection");
592 * Read the MPL115 sensor conversion coefficients.
594 * These are (device specific) constants so we can read them just once.
596 * @return Zero when successful
598 static int MPL115_read_coeffs(void)
600 uint8_t mpl115_coeffs[MPL115_NUM_COEFFS];
603 int8_t sia0MSB, sia0LSB, sib1MSB, sib1LSB, sib2MSB, sib2LSB;
604 int8_t sic12MSB, sic12LSB, sic11MSB, sic11LSB, sic22MSB, sic22LSB;
605 int16_t sia0, sib1, sib2, sic12, sic11, sic22;
609 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd,
615 ERROR ("barometer: MPL115_read_coeffs - problem reading data: %s",
616 sstrerror (errno, errbuf, sizeof (errbuf)));
620 /* Using perhaps less elegant/efficient code, but more readable. */
621 /* a0: 16total 1sign 12int 4fract 0pad */
622 sia0MSB = mpl115_coeffs[0];
623 sia0LSB = mpl115_coeffs[1];
624 sia0 = (int16_t) sia0MSB <<8; /* s16 type, Shift to MSB */
625 sia0 += (int16_t) sia0LSB & 0x00FF; /* Add LSB to 16bit number */
626 mpl115_coeffA0 = (double) (sia0);
627 mpl115_coeffA0 /= 8.0; /* 3 fract bits */
629 /* b1: 16total 1sign 2int 13fract 0pad */
630 sib1MSB= mpl115_coeffs[2];
631 sib1LSB= mpl115_coeffs[3];
632 sib1 = sib1MSB <<8; /* Shift to MSB */
633 sib1 += sib1LSB & 0x00FF; /* Add LSB to 16bit number */
634 mpl115_coeffB1 = (double) (sib1);
635 mpl115_coeffB1 /= 8192.0; /* 13 fract */
637 /* b2: 16total 1sign 1int 14fract 0pad */
638 sib2MSB= mpl115_coeffs[4];
639 sib2LSB= mpl115_coeffs[5];
640 sib2 = sib2MSB <<8; /* Shift to MSB */
641 sib2 += sib2LSB & 0x00FF; /* Add LSB to 16bit number */
642 mpl115_coeffB2 = (double) (sib2);
643 mpl115_coeffB2 /= 16384.0; /* 14 fract */
645 /* c12: 14total 1sign 0int 13fract 9pad */
646 sic12MSB= mpl115_coeffs[6];
647 sic12LSB= mpl115_coeffs[7];
648 sic12 = sic12MSB <<8; /* Shift to MSB only by 8 for MSB */
649 sic12 += sic12LSB & 0x00FF;
650 mpl115_coeffC12 = (double) (sic12);
651 mpl115_coeffC12 /= 4.0; /* 16-14=2 */
652 mpl115_coeffC12 /= 4194304.0; /* 13+9=22 fract */
654 /* c11: 11total 1sign 0int 11fract 11pad */
655 sic11MSB= mpl115_coeffs[8];
656 sic11LSB= mpl115_coeffs[9];
657 sic11 = sic11MSB <<8; /* Shift to MSB only by 8 for MSB */
658 sic11 += sic11LSB & 0x00FF;
659 mpl115_coeffC11 = (double) (sic11);
660 mpl115_coeffC11 /= 32.0; /* 16-11=5 */
661 mpl115_coeffC11 /= 4194304.0; /* 11+11=22 fract */
663 /* c12: 11total 1sign 0int 10fract 15pad */
664 sic22MSB= mpl115_coeffs[10];
665 sic22LSB= mpl115_coeffs[11];
666 sic22 = sic22MSB <<8; /* Shift to MSB only by 8 for MSB */
667 sic22 += sic22LSB & 0x00FF;
668 mpl115_coeffC22 = (double) (sic22);
669 mpl115_coeffC22 /= 32.0; //16-11=5
670 mpl115_coeffC22 /= 33554432.0; /* 10+15=25 fract */
672 DEBUG("barometer: MPL115_read_coeffs: a0=%lf, b1=%lf, b2=%lf, c12=%lf, c11=%lf, c22=%lf",
684 * Convert raw adc values to real data using the sensor coefficients.
686 * @param adc_pressure adc pressure value to be converted
687 * @param adc_temp adc temperature value to be converted
688 * @param pressure computed real pressure
689 * @param temperature computed real temperature
691 static void MPL115_convert_adc_to_real(double adc_pressure,
694 double * temperature)
697 Pcomp = mpl115_coeffA0 + \
698 (mpl115_coeffB1 + mpl115_coeffC11*adc_pressure + mpl115_coeffC12*adc_temp) * adc_pressure + \
699 (mpl115_coeffB2 + mpl115_coeffC22*adc_temp) * adc_temp;
701 *pressure = ((1150.0-500.0) * Pcomp / 1023.0) + 500.0;
702 *temperature = (472.0 - adc_temp) / 5.35 + 25.0;
703 DEBUG ("barometer: MPL115_convert_adc_to_real - got %lf hPa, %lf C",
710 * Read sensor averegaed measurements
712 * @param pressure averaged measured pressure
713 * @param temperature averaged measured temperature
715 * @return Zero when successful
717 static int MPL115_read_averaged(double * pressure, double * temperature)
719 uint8_t mpl115_conv[MPL115_NUM_CONV];
723 int conv_temperature;
725 double adc_temperature;
731 /* start conversion of both temp and presure */
732 retries = MPL115_CONVERSION_RETRIES;
735 /* write 1 to start conversion */
736 res = i2c_smbus_write_byte_data (i2c_bus_fd,
737 MPL115_CMD_CONVERT_BOTH,
745 ERROR ("barometer: MPL115_read_averaged - requesting conversion: %s, " \
746 "will retry at most %d more times",
747 sstrerror (errno, errbuf, sizeof (errbuf)),
752 ERROR ("barometer: MPL115_read_averaged - requesting conversion: %s, "\
753 "too many failed retries",
754 sstrerror (errno, errbuf, sizeof (errbuf)));
759 usleep (10000); /* wait 10ms for the conversion */
761 retries=MPL115_CONVERSION_RETRIES;
764 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd,
774 ERROR ("barometer: MPL115_read_averaged - reading conversion: %s, " \
775 "will retry at most %d more times",
776 sstrerror (errno, errbuf, sizeof (errbuf)),
781 ERROR ("barometer: MPL115_read_averaged - reading conversion: %s, " \
782 "too many failed retries",
783 sstrerror (errno, errbuf, sizeof (errbuf)));
788 conv_pressure = ((mpl115_conv[0] << 8) | mpl115_conv[1]) >> 6;
789 conv_temperature = ((mpl115_conv[2] << 8) | mpl115_conv[3]) >> 6;
790 DEBUG ("barometer: MPL115_read_averaged, raw pressure ADC value = %d, " \
791 "raw temperature ADC value = %d",
795 adc_pressure = averaging_add_sample (&pressure_averaging, conv_pressure);
796 adc_temperature = averaging_add_sample (&temperature_averaging, conv_temperature);
798 MPL115_convert_adc_to_real(adc_pressure, adc_temperature, pressure, temperature);
800 DEBUG ("barometer: MPL115_read_averaged - averaged ADC pressure = %lf / temperature = %lf, " \
801 "real pressure = %lf hPa / temperature = %lf C",
810 /* ------------------------ MPL3115 access ------------------------ */
813 * Detect presence of a MPL3115 pressure sensor by checking register "WHO AM I"
815 * As a sideeffect will leave set I2C slave address.
817 * @return 1 if MPL3115, 0 otherwise
819 static int MPL3115_detect(void)
824 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL3115_I2C_ADDRESS) < 0)
826 ERROR("barometer: MPL3115_detect problem setting i2c slave address to 0x%02X: %s",
828 sstrerror (errno, errbuf, sizeof (errbuf)));
832 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_WHO_AM_I);
833 if(res == MPL3115_WHO_AM_I_RESP)
835 DEBUG ("barometer: MPL3115_detect - positive detection");
839 DEBUG ("barometer: MPL3115_detect - negative detection");
844 * Adjusts oversampling to values supported by MPL3115
846 * MPL3115 supports only power of 2 in the range 1 to 128.
848 static void MPL3115_adjust_oversampling(void)
852 if(config_oversample > 100)
855 mpl3115_oversample = MPL3115_CTRL_REG1_OST_128;
857 else if(config_oversample > 48)
860 mpl3115_oversample = MPL3115_CTRL_REG1_OST_64;
862 else if(config_oversample > 24)
865 mpl3115_oversample = MPL3115_CTRL_REG1_OST_32;
867 else if(config_oversample > 12)
870 mpl3115_oversample = MPL3115_CTRL_REG1_OST_16;
872 else if(config_oversample > 6)
875 mpl3115_oversample = MPL3115_CTRL_REG1_OST_8;
877 else if(config_oversample > 3)
880 mpl3115_oversample = MPL3115_CTRL_REG1_OST_4;
882 else if(config_oversample > 1)
885 mpl3115_oversample = MPL3115_CTRL_REG1_OST_2;
890 mpl3115_oversample = MPL3115_CTRL_REG1_OST_1;
893 DEBUG("barometer: MPL3115_adjust_oversampling - correcting oversampling from %d to %d",
896 config_oversample = new_val;
900 * Read sensor averegaed measurements
902 * @param pressure averaged measured pressure
903 * @param temperature averaged measured temperature
905 * @return Zero when successful
907 static int MPL3115_read(double * pressure, double * temperature)
911 __u8 data[MPL3115_NUM_CONV_VALS];
912 long int tmp_value = 0;
915 /* Set Active - activate the device from standby */
916 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1);
919 ERROR ("barometer: MPL3115_read - cannot read CTRL_REG1: %s",
920 sstrerror (errno, errbuf, sizeof (errbuf)));
924 res = i2c_smbus_write_byte_data(i2c_bus_fd,
925 MPL3115_REG_CTRL_REG1,
926 ctrl | MPL3115_CTRL_REG1_SBYB);
929 ERROR ("barometer: MPL3115_read - problem activating: %s",
930 sstrerror (errno, errbuf, sizeof (errbuf)));
934 /* base sleep is 5ms x OST */
935 usleep(5000 * config_oversample);
937 /* check the flags/status if ready */
938 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
941 ERROR ("barometer: MPL3115_read - cannot read status register: %s",
942 sstrerror (errno, errbuf, sizeof (errbuf)));
946 while ((res & MPL3115_DR_STATUS_DR) != MPL3115_DR_STATUS_DR)
948 /* try some extra sleep... */
951 /* ... and repeat the check. The conversion has to finish sooner or later. */
952 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
955 ERROR ("barometer: MPL3115_read - cannot read status register: %s",
956 sstrerror (errno, errbuf, sizeof (errbuf)));
961 /* Now read all the data in one block. There is address autoincrement. */
962 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd,
963 MPL3115_REG_OUT_P_MSB,
964 MPL3115_NUM_CONV_VALS,
968 ERROR ("barometer: MPL3115_read - cannot read data registers: %s",
969 sstrerror (errno, errbuf, sizeof (errbuf)));
973 tmp_value = (data[0] << 16) | (data[1] << 8) | data[2];
974 *pressure = ((double) tmp_value) / 4.0 / 16.0 / 100.0;
975 DEBUG ("barometer: MPL3115_read - absolute pressure = %lf hPa", *pressure);
979 data[3] = ~data[3] + 1;
980 *temperature = data[3];
981 *temperature = - *temperature;
985 *temperature = data[3];
988 *temperature += (double)(data[4]) / 256.0;
989 DEBUG ("barometer: MPL3115_read - temperature = %lf C", *temperature);
995 * Initialize MPL3115 for barometeric measurements
997 * @return 0 if successful
999 static int MPL3115_init_sensor(void)
1005 /* Reset the sensor. It will reset immediately without ACKing */
1006 /* the transaction, so no error handling here. */
1007 i2c_smbus_write_byte_data(i2c_bus_fd,
1008 MPL3115_REG_CTRL_REG1,
1009 MPL3115_CTRL_REG1_RST);
1011 /* wait some time for the reset to finish */
1014 /* now it should be in standby already so we can go and configure it */
1016 /* Set temperature offset. */
1017 /* result = ADCtemp + offset [C] */
1018 offset = (__s8) (config_temp_offset * 16.0);
1019 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_T, offset);
1022 ERROR ("barometer: MPL3115_init_sensor - problem setting temp offset: %s",
1023 sstrerror (errno, errbuf, sizeof (errbuf)));
1027 /* Set pressure offset. */
1028 /* result = ADCpress + offset [hPa] */
1029 offset = (__s8) (config_press_offset * 100.0 / 4.0);
1030 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_P, offset);
1033 ERROR ("barometer: MPL3115_init_sensor - problem setting pressure offset: %s",
1034 sstrerror (errno, errbuf, sizeof (errbuf)));
1038 /* Enable Data Flags in PT_DATA_CFG - flags on both pressure and temp */
1039 res = i2c_smbus_write_byte_data(i2c_bus_fd,
1040 MPL3115_REG_PT_DATA_CFG,
1041 MPL3115_PT_DATA_DREM \
1042 | MPL3115_PT_DATA_PDEF \
1043 | MPL3115_PT_DATA_TDEF);
1046 ERROR ("barometer: MPL3115_init_sensor - problem setting PT_DATA_CFG: %s",
1047 sstrerror (errno, errbuf, sizeof (errbuf)));
1051 /* Set to barometer with an OSR */
1052 res = i2c_smbus_write_byte_data(i2c_bus_fd,
1053 MPL3115_REG_CTRL_REG1,
1054 mpl3115_oversample);
1057 ERROR ("barometer: MPL3115_init_sensor - problem configuring CTRL_REG1: %s",
1058 sstrerror (errno, errbuf, sizeof (errbuf)));
1065 /* ------------------------ BMP085 access ------------------------ */
1068 * Detect presence of a BMP085 pressure sensor by checking its ID register
1070 * As a sideeffect will leave set I2C slave address.
1072 * @return 1 if BMP085, 0 otherwise
1074 static int BMP085_detect(void)
1079 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, BMP085_I2C_ADDRESS) < 0)
1081 ERROR("barometer: BMP085_detect - problem setting i2c slave address to 0x%02X: %s",
1083 sstrerror (errno, errbuf, sizeof (errbuf)));
1087 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_ID_REG);
1088 if(res == BMP085_CHIP_ID)
1090 DEBUG ("barometer: BMP085_detect - positive detection");
1093 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_VERSION );
1096 ERROR("barometer: BMP085_detect - problem checking chip version: %s",
1097 sstrerror (errno, errbuf, sizeof (errbuf)));
1100 DEBUG ("barometer: BMP085_detect - chip version ML:0x%02X AL:0x%02X",
1106 DEBUG ("barometer: BMP085_detect - negative detection");
1112 * Adjusts oversampling settings to values supported by BMP085
1114 * BMP085 supports only 1,2,4 or 8 samples.
1116 static void BMP085_adjust_oversampling(void)
1120 if( config_oversample > 6 ) /* 8 */
1123 bmp085_oversampling = 3;
1124 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_3;
1125 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_3;
1127 else if( config_oversample > 3 ) /* 4 */
1130 bmp085_oversampling = 2;
1131 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_2;
1132 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_2;
1134 else if( config_oversample > 1 ) /* 2 */
1137 bmp085_oversampling = 1;
1138 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_1;
1139 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_1;
1144 bmp085_oversampling = 0;
1145 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_0;
1146 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_0;
1149 DEBUG("barometer: BMP085_adjust_oversampling - correcting oversampling from %d to %d",
1152 config_oversample = new_val;
1157 * Read the BMP085 sensor conversion coefficients.
1159 * These are (device specific) constants so we can read them just once.
1161 * @return Zero when successful
1163 static int BMP085_read_coeffs(void)
1166 __u8 coeffs[BMP085_NUM_COEFFS];
1169 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd,
1175 ERROR ("barometer: BMP085_read_coeffs - problem reading data: %s",
1176 sstrerror (errno, errbuf, sizeof (errbuf)));
1180 bmp085_AC1 = ((int16_t) coeffs[0] <<8) | (int16_t) coeffs[1];
1181 bmp085_AC2 = ((int16_t) coeffs[2] <<8) | (int16_t) coeffs[3];
1182 bmp085_AC3 = ((int16_t) coeffs[4] <<8) | (int16_t) coeffs[5];
1183 bmp085_AC4 = ((uint16_t) coeffs[6] <<8) | (uint16_t) coeffs[7];
1184 bmp085_AC5 = ((uint16_t) coeffs[8] <<8) | (uint16_t) coeffs[9];
1185 bmp085_AC6 = ((uint16_t) coeffs[10] <<8) | (uint16_t) coeffs[11];
1186 bmp085_B1 = ((int16_t) coeffs[12] <<8) | (int16_t) coeffs[13];
1187 bmp085_B2 = ((int16_t) coeffs[14] <<8) | (int16_t) coeffs[15];
1188 bmp085_MB = ((int16_t) coeffs[16] <<8) | (int16_t) coeffs[17];
1189 bmp085_MC = ((int16_t) coeffs[18] <<8) | (int16_t) coeffs[19];
1190 bmp085_MD = ((int16_t) coeffs[20] <<8) | (int16_t) coeffs[21];
1192 DEBUG("barometer: BMP085_read_coeffs - AC1=%d, AC2=%d, AC3=%d, AC4=%u,"\
1193 " AC5=%u, AC6=%u, B1=%d, B2=%d, MB=%d, MC=%d, MD=%d",
1211 * Convert raw BMP085 adc values to real data using the sensor coefficients.
1213 * @param adc_pressure adc pressure value to be converted
1214 * @param adc_temp adc temperature value to be converted
1215 * @param pressure computed real pressure
1216 * @param temperature computed real temperature
1218 static void BMP085_convert_adc_to_real(long adc_pressure,
1219 long adc_temperature,
1221 double * temperature)
1226 unsigned long B4, B7;
1232 /* calculate real temperature */
1233 X1 = ( (adc_temperature - bmp085_AC6) * bmp085_AC5) >> 15;
1234 X2 = (bmp085_MC << 11) / (X1 + bmp085_MD);
1239 *temperature = (double)T * 0.1;
1241 /* calculate real pressure */
1242 /* in general X1, X2, X3 are recycled while values of B3, B4, B5, B6 are kept */
1246 X1 = ((bmp085_B2 * ((B6 * B6)>>12)) >> 11 );
1247 X2 = (((long)bmp085_AC2 * B6) >> 11);
1249 B3 = (((((long)bmp085_AC1 * 4) + X3) << bmp085_oversampling) + 2) >> 2;
1252 X1 = (((long)bmp085_AC3*B6) >> 13);
1253 X2 = (bmp085_B1*((B6*B6) >> 12) ) >> 16;
1254 X3 = ((X1 + X2) + 2 ) >> 2;
1255 B4 = ((long)bmp085_AC4* (unsigned long)(X3 + 32768)) >> 15;
1258 B7 = (unsigned long)(adc_pressure - B3)*(50000>>bmp085_oversampling);
1259 if( B7 < 0x80000000 )
1267 X1 = (P >> 8) * (P >> 8);
1268 X1 = (X1 * 3038) >> 16;
1269 X2 = ((-7357) * P) >> 16;
1270 P = P + ( ( X1 + X2 + 3791 ) >> 4);
1272 *pressure = P / 100.0; // in [hPa]
1273 DEBUG ("barometer: BMP085_convert_adc_to_real - got %lf hPa, %lf C",
1280 * Read compensated sensor measurements
1282 * @param pressure averaged measured pressure
1283 * @param temperature averaged measured temperature
1285 * @return Zero when successful
1287 static int BMP085_read(double * pressure, double * temperature)
1293 long adc_temperature;
1297 /* start conversion of temperature */
1298 res = i2c_smbus_write_byte_data( i2c_bus_fd,
1299 BMP085_ADDR_CTRL_REG,
1300 BMP085_CMD_CONVERT_TEMP );
1303 ERROR ("barometer: BMP085_read - problem requesting temperature conversion: %s",
1304 sstrerror (errno, errbuf, sizeof (errbuf)));
1308 usleep(BMP085_TIME_CNV_TEMP); /* wait for the conversion */
1310 res = i2c_smbus_read_i2c_block_data( i2c_bus_fd,
1316 ERROR ("barometer: BMP085_read - problem reading temperature data: %s",
1317 sstrerror (errno, errbuf, sizeof (errbuf)));
1321 adc_temperature = ( (unsigned short)measBuff[0] << 8 ) + measBuff[1];
1325 res = i2c_smbus_write_byte_data( i2c_bus_fd,
1326 BMP085_ADDR_CTRL_REG,
1327 bmp085_cmdCnvPress );
1330 ERROR ("barometer: BMP085_read - problem requesting pressure conversion: %s",
1331 sstrerror (errno, errbuf, sizeof (errbuf)));
1335 usleep(bmp085_timeCnvPress); /* wait for the conversion */
1337 res = i2c_smbus_read_i2c_block_data( i2c_bus_fd,
1343 ERROR ("barometer: BMP085_read - problem reading pressure data: %s",
1344 sstrerror (errno, errbuf, sizeof (errbuf)));
1348 adc_pressure = (long)((((ulong)measBuff[0]<<16) | ((ulong)measBuff[1]<<8) | (ulong)measBuff[2] ) >> (8 - bmp085_oversampling));
1351 DEBUG ("barometer: BMP085_read - raw pressure ADC value = %ld, " \
1352 "raw temperature ADC value = %ld",
1356 BMP085_convert_adc_to_real(adc_pressure, adc_temperature, pressure, temperature);
1363 /* ------------------------ Sensor detection ------------------------ */
1365 * Detect presence of a supported sensor.
1367 * As a sideeffect will leave set I2C slave address.
1368 * The detection is done in the order BMP085, MPL3115, MPL115 and stops after
1369 * first sensor beeing found.
1371 * @return detected sensor type
1373 enum Sensor_type Detect_sensor_type(void)
1376 return Sensor_BMP085;
1378 else if(MPL3115_detect())
1379 return Sensor_MPL3115;
1381 else if(MPL115_detect())
1382 return Sensor_MPL115;
1387 /* ------------------------ Common functionality ------------------------ */
1390 * Convert absolute pressure (in hPa) to mean sea level pressure
1392 * Implemented methods are:
1393 * - MSLP_NONE - no converions, returns absolute pressure
1395 * - MSLP_INTERNATIONAL - see http://en.wikipedia.org/wiki/Atmospheric_pressure#Altitude_atmospheric_pressure_variation
1396 * Requires #config_altitude
1398 * - MSLP_DEU_WETT - formula as recommended by the Deutsche Wetterdienst. See
1399 * http://de.wikipedia.org/wiki/Barometrische_H%C3%B6henformel#Theorie
1400 * Requires both #config_altitude and temperature reference(s).
1402 * @param abs_pressure absloute pressure to be converted
1404 * @return mean sea level pressure if successful, NAN otherwise
1406 static double abs_to_mean_sea_level_pressure(double abs_pressure)
1412 DEBUG ("barometer: abs_to_mean_sea_level_pressure: absPressure = %lf, method = %d",
1416 if (config_normalize >= MSLP_DEU_WETT)
1418 result = get_reference_temperature(&temp);
1425 switch(config_normalize)
1428 mean = abs_pressure;
1431 case MSLP_INTERNATIONAL:
1432 mean = abs_pressure / \
1433 pow(1.0 - 0.0065*config_altitude/288.15, 0.0065*0.0289644/(8.31447*0.0065));
1438 double E; /* humidity */
1441 E = 5.6402 * (-0.0916 + exp(0.06*temp) );
1443 E = 18.2194 * (1.0463 - exp(-0.0666*temp) );
1444 x = 9.80665 / (287.05 * (temp+273.15 + 0.12*E + 0.0065*config_altitude/2)) * config_altitude;
1445 mean = abs_pressure * exp(x);
1450 ERROR ("barometer: abs_to_mean_sea_level_pressure: wrong conversion method %d",
1452 mean = abs_pressure;
1459 /* ------------------------ main plugin callbacks ------------------------ */
1462 * Main plugin configuration callback (using simple config)
1464 * @param key configuration key we should process
1465 * @param value configuration value we should process
1467 * @return Zero when successful.
1469 static int collectd_barometer_config (const char *key, const char *value)
1471 DEBUG("barometer: collectd_barometer_config");
1473 if (strcasecmp (key, "Device") == 0)
1475 sfree (config_device);
1476 config_device = strdup (value);
1478 else if (strcasecmp (key, "Oversampling") == 0)
1480 int oversampling_tmp = atoi (value);
1481 if (oversampling_tmp < 1 || oversampling_tmp > 1024)
1483 WARNING ("barometer: collectd_barometer_config: invalid oversampling: %d." \
1484 " Allowed values are 1 to 1024 (for MPL115) or 1 to 128 (for MPL3115) or 1 to 8 (for BMP085).",
1488 config_oversample = oversampling_tmp;
1490 else if (strcasecmp (key, "Altitude") == 0)
1492 config_altitude = atof (value);
1494 else if (strcasecmp (key, "Normalization") == 0)
1496 int normalize_tmp = atoi (value);
1497 if (normalize_tmp < 0 || normalize_tmp > 2)
1499 WARNING ("barometer: collectd_barometer_config: invalid normalization: %d",
1503 config_normalize = normalize_tmp;
1505 else if (strcasecmp (key, "TemperatureSensor") == 0)
1507 if(temp_list_add(temp_list, value))
1512 else if (strcasecmp (key, "PressureOffset") == 0)
1514 config_press_offset = atof(value);
1516 else if (strcasecmp (key, "TemperatureOffset") == 0)
1518 config_temp_offset = atof(value);
1530 * Shutdown callback.
1532 * Close I2C and delete all the buffers.
1534 * @return Zero when successful (at the moment the only possible outcome)
1536 static int collectd_barometer_shutdown(void)
1538 DEBUG ("barometer: collectd_barometer_shutdown");
1540 if(sensor_type == Sensor_MPL115)
1542 averaging_delete (&pressure_averaging);
1543 averaging_delete (&temperature_averaging);
1545 temp_list_delete(&temp_list);
1552 sfree (config_device);
1560 * Plugin read callback for MPL115.
1562 * Dispatching will create values:
1563 * - <hostname>/barometer-mpl115/pressure-normalized
1564 * - <hostname>/barometer-mpl115/pressure-absolute
1565 * - <hostname>/barometer-mpl115/temperature
1567 * @return Zero when successful.
1569 static int MPL115_collectd_barometer_read (void)
1573 double pressure = 0.0;
1574 double temperature = 0.0;
1575 double norm_pressure = 0.0;
1577 value_list_t vl = VALUE_LIST_INIT;
1580 DEBUG("barometer: MPL115_collectd_barometer_read");
1587 /* Rather than delaying init, we will intitialize during first read. This
1588 way at least we have a better chance to have the reference temperature
1589 already available. */
1590 if(!avg_initialized)
1593 for(i=0; i<config_oversample-1; ++i)
1595 result = MPL115_read_averaged(&pressure, &temperature);
1598 ERROR ("barometer: MPL115_collectd_barometer_read - mpl115 read, ignored during init");
1600 DEBUG("barometer: MPL115_collectd_barometer_read - init %d / %d", i+1, config_oversample-1);
1603 avg_initialized = 1;
1606 result = MPL115_read_averaged(&pressure, &temperature);
1610 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1612 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
1613 sstrncpy (vl.plugin, "barometer", sizeof (vl.plugin));
1614 sstrncpy (vl.plugin_instance, "mpl115", sizeof (vl.plugin_instance));
1619 /* dispatch normalized air pressure */
1620 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1621 sstrncpy (vl.type_instance, "normalized", sizeof (vl.type_instance));
1622 values[0].gauge = norm_pressure;
1623 plugin_dispatch_values (&vl);
1625 /* dispatch absolute air pressure */
1626 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1627 sstrncpy (vl.type_instance, "absolute", sizeof (vl.type_instance));
1628 values[0].gauge = pressure;
1629 plugin_dispatch_values (&vl);
1631 /* dispatch sensor temperature */
1632 sstrncpy (vl.type, "temperature", sizeof (vl.type));
1633 sstrncpy (vl.type_instance, "", sizeof (vl.type_instance));
1634 values[0].gauge = temperature;
1635 plugin_dispatch_values (&vl);
1642 * Plugin read callback for MPL3115.
1644 * Dispatching will create values:
1645 * - <hostname>/barometer-mpl3115/pressure-normalized
1646 * - <hostname>/barometer-mpl3115/pressure-absolute
1647 * - <hostname>/barometer-mpl3115/temperature
1649 * @return Zero when successful.
1651 static int MPL3115_collectd_barometer_read (void)
1655 double pressure = 0.0;
1656 double temperature = 0.0;
1657 double norm_pressure = 0.0;
1659 value_list_t vl = VALUE_LIST_INIT;
1662 DEBUG("barometer: MPL3115_collectd_barometer_read");
1669 result = MPL3115_read(&pressure, &temperature);
1673 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1675 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
1676 sstrncpy (vl.plugin, "barometer", sizeof (vl.plugin));
1677 sstrncpy (vl.plugin_instance, "mpl3115", sizeof (vl.plugin_instance));
1682 /* dispatch normalized air pressure */
1683 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1684 sstrncpy (vl.type_instance, "normalized", sizeof (vl.type_instance));
1685 values[0].gauge = norm_pressure;
1686 plugin_dispatch_values (&vl);
1688 /* dispatch absolute air pressure */
1689 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1690 sstrncpy (vl.type_instance, "absolute", sizeof (vl.type_instance));
1691 values[0].gauge = pressure;
1692 plugin_dispatch_values (&vl);
1694 /* dispatch sensor temperature */
1695 sstrncpy (vl.type, "temperature", sizeof (vl.type));
1696 sstrncpy (vl.type_instance, "", sizeof (vl.type_instance));
1697 values[0].gauge = temperature;
1698 plugin_dispatch_values (&vl);
1705 * Plugin read callback for BMP085.
1707 * Dispatching will create values:
1708 * - <hostname>/barometer-bmp085/pressure-normalized
1709 * - <hostname>/barometer-bmp085/pressure-absolute
1710 * - <hostname>/barometer-bmp085/temperature
1712 * @return Zero when successful.
1714 static int BMP085_collectd_barometer_read (void)
1718 double pressure = 0.0;
1719 double temperature = 0.0;
1720 double norm_pressure = 0.0;
1722 value_list_t vl = VALUE_LIST_INIT;
1725 DEBUG("barometer: BMP085_collectd_barometer_read");
1732 result = BMP085_read(&pressure, &temperature);
1736 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1738 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
1739 sstrncpy (vl.plugin, "barometer", sizeof (vl.plugin));
1740 sstrncpy (vl.plugin_instance, "bmp085", sizeof (vl.plugin_instance));
1745 /* dispatch normalized air pressure */
1746 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1747 sstrncpy (vl.type_instance, "normalized", sizeof (vl.type_instance));
1748 values[0].gauge = norm_pressure;
1749 plugin_dispatch_values (&vl);
1751 /* dispatch absolute air pressure */
1752 sstrncpy (vl.type, "pressure", sizeof (vl.type));
1753 sstrncpy (vl.type_instance, "absolute", sizeof (vl.type_instance));
1754 values[0].gauge = pressure;
1755 plugin_dispatch_values (&vl);
1757 /* dispatch sensor temperature */
1758 sstrncpy (vl.type, "temperature", sizeof (vl.type));
1759 sstrncpy (vl.type_instance, "", sizeof (vl.type_instance));
1760 values[0].gauge = temperature;
1761 plugin_dispatch_values (&vl);
1768 * Initialization callback
1770 * Check config, initialize I2C bus access, conversion coefficients and averaging
1773 * @return Zero when successful.
1775 static int collectd_barometer_init (void)
1779 DEBUG ("barometer: collectd_barometer_init");
1781 if (config_device == NULL)
1783 ERROR("barometer: collectd_barometer_init I2C bus device not configured");
1787 if (config_normalize >= MSLP_INTERNATIONAL && isnan(config_altitude))
1789 ERROR("barometer: collectd_barometer_init no altitude configured " \
1790 "for mean sea level pressure normalization.");
1794 if (config_normalize == MSLP_DEU_WETT
1798 ERROR("barometer: collectd_barometer_init no temperature reference "\
1799 "configured for mean sea level pressure normalization.");
1804 i2c_bus_fd = open(config_device, O_RDWR);
1807 ERROR ("barometer: collectd_barometer_init problem opening I2C bus device \"%s\": %s (is loaded mod i2c-dev?)",
1809 sstrerror (errno, errbuf, sizeof (errbuf)));
1813 /* detect sensor type - this will also set slave address */
1814 sensor_type = Detect_sensor_type();
1816 /* init correct sensor type */
1820 case Sensor_MPL3115:
1822 MPL3115_adjust_oversampling();
1824 if(MPL3115_init_sensor())
1827 plugin_register_read ("barometer", MPL3115_collectd_barometer_read);
1834 if (averaging_create (&pressure_averaging, config_oversample))
1836 ERROR("barometer: collectd_barometer_init pressure averaging init failed");
1840 if (averaging_create (&temperature_averaging, config_oversample))
1842 ERROR("barometer: collectd_barometer_init temperature averaging init failed");
1846 if (MPL115_read_coeffs() < 0)
1849 plugin_register_read ("barometer", MPL115_collectd_barometer_read);
1856 BMP085_adjust_oversampling();
1858 if (BMP085_read_coeffs() < 0)
1861 plugin_register_read ("barometer", BMP085_collectd_barometer_read);
1865 /* anything else -> error */
1867 ERROR("barometer: collectd_barometer_init - no supported sensor found");
1876 /* ------------------------ plugin register / entry point ------------------------ */
1879 * Plugin "entry" - register all callback.
1882 void module_register (void)
1884 plugin_register_config ("barometer",
1885 collectd_barometer_config,
1888 plugin_register_init ("barometer", collectd_barometer_init);
1889 plugin_register_shutdown ("barometer", collectd_barometer_shutdown);