-
Notifications
You must be signed in to change notification settings - Fork 0
/
bme680.h
237 lines (190 loc) · 6.63 KB
/
bme680.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
//
// Read Bosch BME680 registers and compute values
// author: [email protected]
// started: 2021/11/10
//
#include <fcntl.h>
#include <unistd.h>
#include <stdint.h>
#include <sys/types.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
#ifndef BME680_H
#define BME680_H
/*
sample code found at:
https://elinux.org/Interfacing_with_I2C_Devices
https://www.kernel.org/doc/html/v5.4/i2c/dev-interface.html
https://gist.github.com/JamesDunne/9b7fbedb74c22ccc833059623f47beb7
datasheet:
https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme680-ds001.pdf
*/
typedef unsigned char u8;
// bme680 defines, from rev 1.6 of data sheet
// page 14 - control register in section 5.3.1.3
// sleep mode
#define op_mode_sleep 0x00
// triggers single measurement
#define op_mode_forced 0x01
// page 29
#define ctrl_op_mode 0x74
// page 30
#define ctrl_chip_id 0xd0
// page 15 - suggested oversampling - use one write command - 0x00 means do not perform
// first osrs_h
#define oversample_humidity 0x01
// second osrs_t - section 5.3.2.2
#define oversample_temperature 0x02
// third osrs_p
#define oversample_presssure 0x10
// ignore gas for now - but outline is on page 15
// page 16 has flow chart for all readings
// page 17 - section 3.3.1 -
// temperature calculation formula
// page 18 - registers for value temperature retrieval:
#define calibration_parm_t1_msb 0xea
#define calibration_parm_t1_lsb 0xe9
#define calibration_parm_t2_msb 0x8b
#define calibration_parm_t2_lsb 0x8a
#define calibration_parm_t3 0x8c
#define temp_adc_hi 0x22
#define temp_adc_mid 0x23
#define temp_adc_lo 0x24
// page 30 section 5.3.2.2 - shared with pressure
#define temperature_control 0x74
#define temperature_os_skip 0x00
#define temperature_os_x1 0b00100000
#define temperature_os_x2 0b01000000
#define temperature_os_x4 0b01100000
#define temperature_os_x8 0b10000000
#define temperature_os_x16 0b10100000
// page 19 - registers for value pressure retrieval:
#define calibration_parm_p1_msb 0x8f
#define calibration_parm_p1_lsb 0x8e
#define calibration_parm_p2_msb 0x91
#define calibration_parm_p2_lsb 0x90
#define calibration_parm_p3 0x92
#define calibration_parm_p4_msb 0x95
#define calibration_parm_p4_lsb 0x94
#define calibration_parm_p5_msb 0x97
#define calibration_parm_p5_lsb 0x96
#define calibration_parm_p6 0x99
#define calibration_parm_p7 0x98
#define calibration_parm_p8_msb 0x9d
#define calibration_parm_p8_lsb 0x9c
#define calibration_parm_p9_msb 0x9f
#define calibration_parm_p9_lsb 0x9e
#define calibration_parm_pa 0xa0
#define pressure_adc_msb 0x1f
#define pressure_adc_mid 0x20
#define pressure_adc_lsb 0x21
// page 31 section 5.3.2.3 - shared with temperature
#define pressure_control 0x74
#define pressure_os_skip 0x00
#define pressure_os_x1 0b00000100
#define pressure_os_x2 0b00001000
#define pressure_os_x4 0b00001100
#define pressure_os_x8 0b00010000
#define pressure_os_x16 0b00010100
// page 20 - registers for value humidity retrieval:
#define calibration_parm_h1_msb 0xe3
#define calibration_parm_h1_lsb 0xe2
#define calibration_parm_h2_msb 0xe1
#define calibration_parm_h2_lsb 0xe2
#define calibration_parm_h3 0xe4
#define calibration_parm_h4 0xe5
#define calibration_parm_h5 0xe6
#define calibration_parm_h6 0xe7
#define calibration_parm_h7 0xe8
#define humidity_adc_msb 0x25
#define humidity_adc_lsb 0x26
// page 30 section 5.3.2.1
#define humidity_control 0x72
#define humidity_os_skip 0x00
#define humidity_os_x1 0b00000001
#define humidity_os_x2 0b00000010
#define humidity_os_x4 0b00000011
#define humidity_os_x8 0b00000100
#define humidity_os_x16 0b00000101
// page 31 section 5.3.2.4 - IIR filter control
// temperature & pressure
#define iir_filter_control 0x75
#define iir_filter_coef_0 0b00000000
#define iir_filter_coef_1 0b00000100
#define iir_filter_coef_3 0b00001000
#define iir_filter_coef_7 0b00001100
#define iir_filter_coef_15 0b00010000
#define iir_filter_coef_31 0b00010100
#define iir_filter_coef_63 0b00011000
#define iir_filter_coef_127 0b00011100
// page 22 - registers for value heater:
#define heater_parm_g1 0xed
#define heater_parm_g2_msb 0xec
#define heater_parm_g2_lsb 0xeb
#define heater_parm_g3 0xee
#define heater_range 0x02
#define heater_value 0x00
// page 23 - registers for value gas:
#define gas_adc_msb 0x2a
#define gas_adc_lsb 0x2b
#define gas_range 0x2b
#define gas_range_sw_error 0x04
// page 36 - status registers
#define measurement_status 0x1d
#define status_new_data 0b10000000
#define status_measuring_gas 0b01000000
#define status_measuring 0b00100000
#define status_measuring_gas_ix 0b00001111
// end bme680 definitions
int open_i2c_bus( int id_bus );
int open_i2c_device( int id_bus, u8 id_device );
int read_registers( int fd, u8 reg, u8* data, int length );
int read_register( int fd, u8 reg, u8* data );
int read_register_u8( int fd, u8 reg, uint8_t* data );
int read_register_i8( int fd, u8 reg, int8_t* data );
int write_register( int fd, u8 reg, u8 data );
int read_uint16( int fd, u8 reg, uint16_t* data );
int read_int16( int fd, u8 reg, int16_t* data );
int check_chip_id( int fd_bme680 );
struct temperature {
uint16_t par_t1;
int16_t par_t2;
int8_t par_t3;
uint32_t raw;
int32_t fine; // used in pressure
int32_t compensated; // _.xx celcius
};
int read_temperature_calibration( int fd_bme680, struct temperature* t );
void compensate_temperature( struct temperature* t );
struct pressure {
uint16_t par_p1;
int16_t par_p2;
int8_t par_p3;
int16_t par_p4;
int16_t par_p5;
int8_t par_p6;
int8_t par_p7;
int16_t par_p8;
int16_t par_p9;
uint8_t par_p10;
uint32_t raw;
int32_t compensated; // pascal
};
int read_pressure_calibration( int fd_bme680, struct pressure* p );
void tp( struct pressure* p, const struct temperature* t );
void compensate_pressure( struct pressure* p, const struct temperature* t );
struct humidity {
uint16_t par_h1;
uint16_t par_h2;
int8_t par_h3;
int8_t par_h4;
int8_t par_h5;
uint8_t par_h6;
int8_t par_h7;
uint32_t raw;
int32_t compensated;
};
int read_humidity_calibration( int fd_bme680, struct humidity* h );
void compensate_humidity( struct humidity* h, const struct temperature* t );
int measure_pth( int fd_bme680, int32_t* pressure, int32_t* temperature, int32_t* humidity );
#endif