Motoo Tanaka
My trial of BME280 library, tested with Adafruit BME280 module
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BME280.cpp
00001 #include "mbed.h" 00002 #include "BME280.h" 00003 00004 /* internal registers */ 00005 #define REG_HUM_LSB 0xFE 00006 #define REG_HUM_MSB 0xFD 00007 #define REG_TEMP_XLSB 0xFC 00008 #define REG_TEMP_LSB 0xFB 00009 #define REG_TEMP_MSB 0xFA 00010 #define REG_PRESS_XLSB 0xF9 00011 #define REG_PRESS_LSB 0xF8 00012 #define REG_PRESS_MSB 0xF7 00013 #define REG_CONFIG 0xF5 00014 #define REG_CTRL_MEAS 0xF4 00015 #define REG_STATUS 0xF3 00016 #define REG_CTRL_HUM 0xF2 00017 #define REG_RESET 0xE0 00018 #define REG_ID 0xD0 00019 00020 #define REG_CALIB00 0x88 00021 #define REG_CALIB25 0xA1 00022 #define REG_CALIB26 0xE1 00023 #define REG_CALIB41 0xF0 00024 00025 /** Trimming parameters */ 00026 /* temperature */ 00027 #define REG_T1_LSB 0x88 00028 #define REG_T1_MSB 0x89 00029 #define REG_T2_LSB 0x8A 00030 #define REG_T2_MSB 0x8B 00031 #define REG_T3_LSB 0x8C 00032 #define REG_T3_MSB 0x8D 00033 /* pressure */ 00034 #define REG_P1_LSB 0x8E 00035 #define REG_P1_MSB 0x8F 00036 #define REG_P2_LSB 0x90 00037 #define REG_P2_MSB 0x91 00038 #define REG_P3_LSB 0x92 00039 #define REG_P3_MSB 0x93 00040 #define REG_P4_LSB 0x94 00041 #define REG_P4_MSB 0x95 00042 #define REG_P5_LSB 0x96 00043 #define REG_P5_MSB 0x97 00044 #define REG_P6_LSB 0x98 00045 #define REG_P6_MSB 0x99 00046 #define REG_P7_LSB 0x9A 00047 #define REG_P7_MSB 0x9B 00048 #define REG_P8_LSB 0x9C 00049 #define REG_P8_MSB 0x9D 00050 #define REG_P9_LSB 0x9E 00051 #define REG_P9_MSB 0x9F 00052 /* humidity */ 00053 #define REG_H1 0xA1 00054 #define REG_H2_LSB 0xE1 00055 #define REG_H2_MSB 0xE2 00056 #define REG_H3 0xE3 00057 #define REG_H4 0xE4 00058 #define REG_H5 0xE5 00059 #define REG_H6 0xE7 00060 00061 /* 00062 * Register description 00063 * 0xD0 "id" 00064 * chip identification number chip_id[7:0], which is 0x60 00065 * 00066 * 0xE0 "reset" 00067 * Software reset register, writing 0xB6 causes complete power-on-reset. 00068 * 00069 * 0xF2 "ctrl_hum" 00070 * Specifies the humidity data acquision options. 00071 * Note: Changes to this register only become effective after a write 00072 * operaion to "ctrl_meas". 00073 * bit[2:0] osrs_h[2:0] Controls oversampling of humidity data. 00074 * 000: Skipped (output set to 0x8000) 00075 * 001: oversampling x1 00076 * 010: oversampling x2 00077 * 011: oversampling x4 00078 * 100: oversampling x8 00079 * 101, others, oversampling x16 00080 * 00081 * 0xF3 "status" 00082 * bit[3] measuring[0] Automatically set to '1' during conversion 00083 * and back to '0' when done 00084 * bit[0] im_update[0] Automatically set to '1' during NVM data copy 00085 * and back to '0' when done 00086 * 00087 * 0xF4 "ctrl_meas" 00088 * Specifies the pressure and temperature data acquision options. 00089 * Note: This register needs to be written after canging "ctrl_hum" to take effect. 00090 * bit[7:5] osrs_t[2:0] Controls oversampling of temperature data 00091 * bit value is similar to osrs_h (except 000 output set to 0x80000) 00092 * bit[4:2] osrs_p[2:0] Controls oversampling of pressure data 00093 * bit value is similar to osrs_h (except 000 output set to 0x80000) 00094 * bit[1:0] mode[1:0] Controls the sensor mode. 00095 * 00: Sleep mode 00096 * 01: Forced mode 00097 * 10: Forced mode 00098 * 11: Normal mode 00099 * 00100 * 0xF5 "config" 00101 * Specifies the rate, filter and interface options. 00102 * Writes to "config" in normal mode may be ignored. 00103 * In sleep mode writes are not ignored. 00104 * bit[7:5] t_sb[2:0] Controls inactive duration t_standby in normal mode. 00105 * 000: 0.5 [ms] 00106 * 001: 62.5 [ms] 00107 * 010: 125 [ms] 00108 * 011: 250 [ms] 00109 * 100: 500 [ms] 00110 * 101: 1000 [ms] 00111 * 110: 10 [ms] 00112 * 111: 20 [ms] 00113 * bit[4:2] filter[2:0] Controls the time constant of the IIR filter. 00114 * 000: Filter off 00115 * 001: 2 00116 * 010: 4 00117 * 011: 8 00118 * 100, others: 16 00119 * 00120 * 0xF7 .. 0xF9 "press" (_msb, _lsb, _xlsb) 00121 * 0xF7 bit[7:0] press_msb[7:0] MSB part up[19:12] 00122 * 0xF8 bit[7:0] press_lsb[7:0] LSB part up[11:4] 00123 * 0xF9 bit[7:4] press_xlsb[3:0] XLSB part up[3:0] 00124 * 00125 * 0xFA .. 0xFC "temp" (_msb, _lsb, _xlsb) 00126 * 0xFA bit[7:0] temp_msb[7:0] MSB part ut[19:12] 00127 * 0xFB bit[7:0] temp_lsb[7:0] LSB part ut[11:4] 00128 * 0xFC bit[7:4] temp_xlsp[3:0] XLSB part ut[3:0] 00129 * 00130 * 0xFD .. 0xFE "hum" (_msb, _lsb) 00131 * 0xFD bit[7:0] hum_msb[7:0] MSB part uh[15:8] 00132 * 0xFE bit[7:0] hum_lsb[7:0] LSB part uh[7:0] 00133 */ 00134 /* 00135 * Compensation parameter storage, naming and data type 00136 * Register addr, Register content, Data type 00137 * 0x88/0x89, dig_T1[7:0]/[15:8], unsigned short 00138 * 0x8A/0x8B, dig_T2[7:0]/[15:8], signed short 00139 * 0x8C/0x8D, dig_T3[7:0]/[15:8], signed short 00140 * 0x8E/0x8F, dig_P1[7:0]/[15:8], unsigned short 00141 * 0x90/0x91, dig_P2[7:0]/[15:8], signed short 00142 * 0x92/0x93, dig_P3[7:0]/[15:8], signed short 00143 * 0x94/0x95, dig_P4[7:0]/[15:8], signed short 00144 * 0x96/0x97, dig_P5[7:0]/[15:8], signed short 00145 * 0x98/0x99, dig_P6[7:0]/[15:8], signed short 00146 * 0x9A/0x9B, dig_P7[7:0]/[15:8], signed short 00147 * 0x9C/0x9D, dig_P8[7:0]/[15:8], signed short 00148 * 0x9E/0x9F, dig_P9[7:0]/[15:8], signed short 00149 * 0xA1, dig_H1[7:0], unsigned char 00150 * 0xE1/0xE2, dig_H2[7:0]/[15:8], signed short 00151 * 0xE3, dig_H3[7:0], unsigned char 00152 * 0xE4/0xE5[3:0], dig_H4[11:4]/[3:0] signed short 00153 * 0xE5[7:4]/0xE6, dig_H5[3:0]/[11:4] signed short 00154 * 0xE7, dig_H6[7:0], signed char 00155 */ 00156 00157 void BME280::init(void) 00158 { 00159 uint8_t data[18] ; 00160 00161 data[0] = REG_CTRL_HUM ; 00162 data[1] = 0x03 ; /* Humidity oversampling x4 */ 00163 writeRegs(data, 2) ; 00164 00165 data[0] = REG_CTRL_MEAS ; 00166 data[1] = (0x3 << 5) /* temp oversample x4 */ 00167 | (0x3 << 2) /* pres oversample x4 */ 00168 | (0x00) /* Sleep Mode */ 00169 ; 00170 writeRegs(data, 2) ; 00171 00172 data[0] = REG_CONFIG ; 00173 data[1] = (0x4 << 5) /* standby 500ms */ 00174 | (0x0 << 2) /* filter off */ 00175 | (0x0) /* spi 4wire mode */ 00176 ; 00177 writeRegs(data, 2) ; 00178 00179 /* read dig_T regs */ 00180 readRegs(REG_T1_LSB, data, 6) ; 00181 dig_T1 = (data[1] << 8) | data[0] ; 00182 dig_T2 = (data[3] << 8) | data[2] ; 00183 dig_T3 = (data[5] << 8) | data[4] ; 00184 // printf("dig_T1:0x%04X, dig_T2:0x%04X, dig_T3:0x%04X\n",dig_T1, dig_T2, dig_T3) ; 00185 00186 /* read dig_P regs */ 00187 readRegs(REG_P1_LSB, data, 18) ; 00188 dig_P1 = (data[ 1] << 8) | data[ 0] ; 00189 dig_P2 = (data[ 3] << 8) | data[ 2] ; 00190 dig_P3 = (data[ 5] << 8) | data[ 4] ; 00191 dig_P4 = (data[ 7] << 8) | data[ 6] ; 00192 dig_P5 = (data[ 9] << 8) | data[ 8] ; 00193 dig_P6 = (data[11] << 8) | data[10] ; 00194 dig_P7 = (data[13] << 8) | data[12] ; 00195 dig_P8 = (data[15] << 8) | data[14] ; 00196 dig_P9 = (data[17] << 8) | data[16] ; 00197 // printf("dig_P1:0x%04X, dig_P2:0x%04X, dig_P3:0x%04X\n",dig_P1, dig_P2, dig_P3) ; 00198 // printf("dig_P4:0x%04X, dig_P5:0x%04X, dig_P6:0x%04X\n",dig_P4, dig_P5, dig_P6) ; 00199 // printf("dig_P7:0x%04X, dig_P8:0x%04X, dig_P9:0x%04X\n",dig_P7, dig_P8, dig_P9) ; 00200 00201 /* read dig_H regs */ 00202 readRegs(REG_H1, data, 1) ; 00203 dig_H1 = data[0] ; 00204 readRegs(REG_H2_LSB, data, 2) ; 00205 dig_H2 = (data[1] << 8) | data[0] ; 00206 readRegs(REG_H3, data, 1) ; 00207 dig_H3 = data[0] ; 00208 readRegs(REG_H4, data, 3) ; 00209 dig_H4 = (data[0] << 4) | (data[1] & 0x0F) ; 00210 dig_H5 = (data[2] << 4) | (data[1] >> 4) ; 00211 readRegs(REG_H6, data, 1) ; 00212 dig_H6 = data[0] ; 00213 // printf("dig_H1:0x%04X, dig_H2:0x%04X, dig_H3:0x%04X\n",dig_H1, dig_H2, dig_H3) ; 00214 // printf("dig_H4:0x%04X, dig_H5:0x%04X, dig_H6:0x%04X\n",dig_H4, dig_H5, dig_H6) ; 00215 00216 trigger() ; /* dummy measure */ 00217 } 00218 00219 BME280::BME280(PinName sda, PinName scl, int addr) 00220 { 00221 m_i2c = new I2C(sda, scl) ; 00222 m_addr = (addr << 1) ; 00223 m_spi = 0 ; 00224 m_cs = 0 ; 00225 init() ; 00226 } 00227 00228 BME280::BME280(PinName sck, PinName miso, PinName mosi, PinName cs) 00229 { 00230 m_cs = new DigitalOut(cs, 1) ; 00231 m_spi = new SPI(mosi, miso, sck) ; 00232 m_spi->format(8, 3) ; 00233 m_i2c = 0 ; 00234 m_addr = 0 ; 00235 init() ; 00236 } 00237 00238 BME280::~BME280() 00239 { 00240 if (m_spi) { 00241 delete m_spi ; 00242 delete m_cs ; 00243 } 00244 if (m_i2c) { 00245 delete m_i2c ; 00246 m_addr = 0 ; 00247 } 00248 } 00249 00250 void BME280::i2c_readRegs(int addr, uint8_t * data, int len) { 00251 char t[1] = {addr} ; 00252 m_i2c->write(m_addr, t, 1, true) ; 00253 m_i2c->read(m_addr, (char*)data, len) ; 00254 } 00255 00256 void BME280::i2c_writeRegs(uint8_t * data, int len) { 00257 m_i2c->write(m_addr, (char *)data, len) ; 00258 } 00259 00260 void BME280::spi_readRegs(int addr, uint8_t * data, int len) { 00261 *m_cs = 0 ; 00262 m_spi->write(addr | 0x80) ; 00263 for (int i = 0 ; i < len ; i++ ) { 00264 data[i] = m_spi->write((addr+i)|0x80) ; 00265 } 00266 m_spi->write(0x00) ; // to terminate read mode 00267 *m_cs = 1 ; 00268 } 00269 00270 void BME280::spi_writeRegs(uint8_t * data, int len) { 00271 *m_cs = 0 ; 00272 for (int i = 0 ; i < len-1 ; i++ ) { 00273 m_spi->write((data[0]+i)^0x80) ; /* register address */ 00274 m_spi->write(data[i+1]) ; /* data to write */ 00275 00276 } 00277 *m_cs = 1 ; 00278 } 00279 00280 void BME280::readRegs(int addr, uint8_t *data, int len) 00281 { 00282 if (m_spi) { 00283 spi_readRegs(addr, data, len) ; 00284 } else if (m_i2c) { 00285 i2c_readRegs(addr, data, len) ; 00286 } 00287 } 00288 00289 void BME280::writeRegs(uint8_t *data, int len) 00290 { 00291 if (m_spi) { 00292 spi_writeRegs(data, len) ; 00293 } else if (m_i2c) { 00294 i2c_writeRegs(data, len) ; 00295 } 00296 } 00297 00298 void BME280::reset(void) 00299 { 00300 uint8_t data[2] ; 00301 data[0] = REG_RESET ; 00302 data[1] = 0xB6 ; 00303 writeRegs(data, 2) ; 00304 } 00305 00306 void BME280::trigger(void) 00307 { 00308 uint8_t data[2] ; 00309 readRegs(REG_CTRL_MEAS, &data[1], 1) ; 00310 00311 data[0] = REG_CTRL_MEAS ; 00312 data[1] = (data[1] & 0xFC) /* keep oversampling */ 00313 | (0x2) /* Forced Mode */ 00314 ; 00315 writeRegs(data, 2) ; 00316 } 00317 00318 uint8_t BME280::busy(void) 00319 { 00320 uint8_t data[1] ; 00321 readRegs(REG_STATUS, data, 1) ; 00322 return( data[0] & 0x9 ) ; 00323 } 00324 00325 uint8_t BME280::getID(void) 00326 { 00327 uint8_t data[1] ; 00328 readRegs(REG_ID, data, 1) ; 00329 return(data[0]) ; 00330 } 00331 00332 float BME280::getTemperature(void) 00333 { 00334 float tempf ; 00335 uint8_t data[3] ; 00336 BME280_S32_t var1, var2, T ; 00337 BME280_S32_t adc_T ; 00338 00339 readRegs(REG_TEMP_MSB, data, 3) ; 00340 adc_T = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4); 00341 00342 var1 = ((((adc_T>>3) - ((BME280_S32_t)dig_T1<<1))) * ((BME280_S32_t)dig_T2)) >> 11; 00343 var2 = (((((adc_T>>4) - ((BME280_S32_t)dig_T1)) * ((adc_T>>4) - ((BME280_S32_t)dig_T1))) >> 12) * 00344 ((BME280_S32_t)dig_T3)) >> 14; 00345 t_fine = var1 + var2; 00346 T = (t_fine * 5 + 128) >> 8; 00347 00348 tempf = (float)T; 00349 return (tempf/100.0f); 00350 } 00351 00352 float BME280::getPressure(void) 00353 { 00354 BME280_S32_t adc_P ; 00355 BME280_S64_t var1, var2, p ; 00356 float pressf; 00357 uint8_t data[3]; 00358 00359 readRegs(REG_PRESS_MSB, data, 3) ; 00360 adc_P = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4); 00361 00362 var1 = ((BME280_S64_t)t_fine) - 128000; 00363 var2 = var1 * var1 * (BME280_S64_t)dig_P6; 00364 var2 = var2 + ((var1*(BME280_S64_t)dig_P5)<<17); 00365 var2 = var2 + (((BME280_S64_t)dig_P4)<<35); 00366 var1 = ((var1 * var1 * (BME280_S64_t)dig_P3)>>8) + ((var1 * (BME280_S64_t)dig_P2)<<12); 00367 var1 = (((((BME280_S64_t)1)<<47)+var1))*((BME280_S64_t)dig_P1)>>33; 00368 if (var1 == 0) { 00369 return 0; // avoid exception caused by division by zero 00370 } 00371 p = 1048576-adc_P; 00372 p = (((p<<31)-var2)*3125)/var1; 00373 var1 = (((BME280_S64_t)dig_P9) * (p>>13) * (p>>13)) >> 25; 00374 var2 = (((BME280_S64_t)dig_P8) * p) >> 19; 00375 p = ((p + var1 + var2) >> 8) + (((BME280_S64_t)dig_P7)<<4); 00376 00377 pressf = (float)(p >> 8) ; 00378 return (pressf/100.0f); 00379 } 00380 00381 float BME280::getHumidity(void) 00382 { 00383 BME280_S32_t adc_H; 00384 BME280_S32_t v_x1_u32r ; 00385 float humf; 00386 uint8_t data[2]; 00387 00388 readRegs(REG_HUM_MSB, data, 2) ; 00389 adc_H = (data[0] << 8) | data[1]; 00390 00391 v_x1_u32r = (t_fine - ((BME280_S32_t)76800)); 00392 v_x1_u32r = (((((adc_H << 14) - (((BME280_S32_t)dig_H4) << 20) - (((BME280_S32_t)dig_H5) * v_x1_u32r)) + 00393 ((BME280_S32_t)16384)) >> 15) * (((((((v_x1_u32r * ((BME280_S32_t)dig_H6)) >> 10) * (((v_x1_u32r * 00394 ((BME280_S32_t)dig_H3)) >> 11) + ((BME280_S32_t)32768))) >> 10) + ((BME280_S32_t)2097152)) * 00395 ((BME280_S32_t)dig_H2) + 8192) >> 14)); 00396 v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((BME280_S32_t)dig_H1)) >> 4)); 00397 v_x1_u32r = (v_x1_u32r < 0 ? 0 : v_x1_u32r); 00398 v_x1_u32r = (v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r); 00399 humf = (float)(v_x1_u32r >> 12) ; 00400 00401 return (humf/1024.0f); 00402 }
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