44 #include "bme280-arch.h" 45 #include "lib/sensors.h" 48 unsigned short dig_t1;
51 unsigned short dig_p1;
71 bme280_t_overscale100(int32_t ut)
75 v1 = ((((ut >> 3) - ((int32_t)bm.dig_t1 << 1))) *
76 ((int32_t)bm.dig_t2)) >> 11;
78 v2 = (((((ut >> 4) - ((int32_t)bm.dig_t1)) * ((ut >> 4) -
79 ((int32_t)bm.dig_t1))) >> 12) * ((int32_t)bm.dig_t3)) >> 14;
82 t = (bm.t_fine * 5 + 128) >> 8;
92 v1 = (((int32_t)bm.t_fine) >> 1) - (int32_t)64000;
93 v2 = (((v1 >> 2) * (v1 >> 2)) >> 11) * ((int32_t)bm.dig_p6);
94 v2 = v2 + ((v1 * ((int32_t)bm.dig_p5)) << 1);
95 v2 = (v2 >> 2) + (((int32_t)bm.dig_p4) << 16);
97 v1 = (((bm.dig_p3 * (((v1 >> 2) * (v1 >> 2)) >> 13)) >> 3) +
98 ((((int32_t)bm.dig_p2) * v1) >> 1)) >> 18;
100 v1 = ((((32768 + v1)) * ((int32_t)bm.dig_p1)) >> 15);
106 p = (((uint32_t)(((int32_t)1048576) - up) - (v2 >> 12))) * 3125;
109 p = (p << 1) / ((uint32_t)v1);
111 p = (p / (uint32_t)v1) * 2;
114 v1 = (((int32_t)bm.dig_p9) * ((int32_t)(((p >> 3) * (p >> 3)) >> 13))) >> 12;
115 v2 = (((int32_t)(p >> 2)) * ((int32_t)bm.dig_p8)) >> 13;
116 p = (uint32_t)((int32_t)p + ((v1 + v2 + bm.dig_p7) >> 4));
122 bme280_p_overscale256(int32_t up)
126 v1 = ((int64_t)bm.t_fine) - 128000;
127 v2 = v1 * v1 * (int64_t)bm.dig_p6;
128 v2 = v2 + ((v1 * (int64_t)bm.dig_p5) << 17);
129 v2 = v2 + (((int64_t)bm.dig_p4) << 35);
130 v1 = ((v1 * v1 * (int64_t)bm.dig_p3) >> 8) + ((v1 * (int64_t)bm.dig_p2) << 12);
131 v1 = (((((int64_t)1) << 47) + v1)) * ((int64_t)bm.dig_p1) >> 33;
138 p = (((p << 31) - v2) * 3125) / v1;
139 v1 = (((int64_t)bm.dig_p9) * (p >> 13) * (p >> 13)) >> 25;
140 v2 = (((int64_t)bm.dig_p8) * p) >> 19;
141 p = (((p + v1 + v2) >> 8) + (((int64_t)bm.dig_p7) << 4));
147 bme280_h_overscale1024(int32_t uh)
150 v1 = (bm.t_fine - ((int32_t)76800));
151 v1 = (((((uh << 14) - (((int32_t)bm.dig_h4) << 20) - (((int32_t)bm.dig_h5) * v1)) + ((int32_t)16384)) >> 15)
152 * (((((((v1 * ((int32_t)bm.dig_h6)) >> 10) * (((v1 * ((int32_t)bm.dig_h3)) >> 11) + ((int32_t)32768)))
153 >> 10) + ((int32_t)2097152)) * ((int32_t)bm.dig_h2) + 8192) >> 14));
154 v1 = (v1 - (((((v1 >> 15) * (v1 >> 15)) >> 7) * ((int32_t)bm.dig_h1)) >> 4));
155 v1 = (v1 < 0 ? 0 : v1);
156 v1 = (v1 > 419430400 ? 419430400 : v1);
157 return (uint32_t)(v1 >> 12);
160 bme280_init(uint8_t mode)
165 bme280_arch_i2c_init();
168 bme280_arch_i2c_read_mem(BME280_ADDR, 0xD0, buf, 1);
169 if(buf[0] != BME280_CHIP_ID) {
173 bme280_arch_i2c_write_mem(BME280_ADDR, BME280_CNTL_RESET, 0xB6);
175 for(i = 0; i < BME280_MAX_WAIT; i++) {
179 memset(buf, 0,
sizeof(buf));
182 bme280_arch_i2c_read_mem(BME280_ADDR, BME280_DIG_T1_ADDR, buf,
sizeof(buf));
183 bm.dig_t1 = ((uint16_t)buf[1] << 8) | (uint16_t)buf[0];
184 bm.dig_t2 = ((int16_t)buf[3] << 8) | (uint16_t)buf[2];
185 bm.dig_t3 = ((int16_t)buf[5] << 8) | (uint16_t)buf[4];
186 bm.dig_p1 = ((uint16_t)buf[7] << 8) | (uint16_t)buf[6];
187 bm.dig_p2 = ((int16_t)buf[9] << 8) | (uint16_t)buf[8];
188 bm.dig_p3 = ((int16_t)buf[11] << 8) | (uint16_t)buf[10];
189 bm.dig_p4 = ((int16_t)buf[13] << 8) | (uint16_t)buf[12];
190 bm.dig_p5 = ((int16_t)buf[15] << 8) | (uint16_t)buf[14];
191 bm.dig_p6 = ((int16_t)buf[17] << 8) | (uint16_t)buf[16];
192 bm.dig_p7 = ((int16_t)buf[19] << 8) | (uint16_t)buf[18];
193 bm.dig_p8 = ((int16_t)buf[21] << 8) | (uint16_t)buf[20];
194 bm.dig_p9 = ((int16_t)buf[23] << 8) | (uint16_t)buf[22];
196 bm.dig_h1 = (
unsigned char)buf[25];
199 bme280_arch_i2c_read_mem(BME280_ADDR, BME280_DIG_H2_ADDR, buf, 8);
200 bm.dig_h2 = ((int16_t)buf[1] << 8) | (uint16_t)buf[0];
201 bm.dig_h3 = (
unsigned char)buf[2];
202 bm.dig_h4 = ((int16_t)buf[3] << 4) | (((uint16_t)buf[4]) & 0xF);
203 bm.dig_h5 = ((int16_t)buf[6] << 4) | (((uint16_t)buf[5]) & 0xF);
204 bm.dig_h6 = (
unsigned char)buf[7];
210 bme280_read(uint8_t mode)
213 uint8_t buf[8], sleep;
215 memset(buf, 0,
sizeof(buf));
218 if(mode == BME280_MODE_NONE || mode != bm.mode) {
225 if(mode == BME280_MODE_WEATHER) {
227 bme280_arch_i2c_write_mem(BME280_ADDR, BME280_CNTL_HUM, 0x01);
231 bme280_arch_i2c_write_mem(BME280_ADDR, BME280_CONTROL, 0x00);
235 bme280_arch_i2c_write_mem(BME280_ADDR, BME280_CNTL_MEAS, 0x26);
237 for(i = 0; i < BME280_MAX_WAIT; i++) {
238 bme280_arch_i2c_read_mem(BME280_ADDR, BME280_CNTL_MEAS, &sleep, 1);
246 if(i == BME280_MAX_WAIT) {
254 bme280_arch_i2c_read_mem(BME280_ADDR, BME280_PRESS, buf, 8);
255 ut = (uint32_t)(buf[3]) << 12 | (uint32_t)(buf[4]) << 4 | (uint32_t)buf[5] >> 4;
256 up = (uint32_t)(buf[0]) << 12 | (uint32_t)(buf[1]) << 4 | (uint32_t)buf[2] >> 4;
257 uh = (uint32_t)(buf[6]) << 8 | (uint32_t)buf[7];
259 bme280_mea.t_overscale100 = bme280_t_overscale100(ut);
260 bme280_mea.h_overscale1024 = bme280_h_overscale1024(uh);
262 bme280_mea.p_overscale256 = bme280_p_overscale256(up);
264 bme280_mea.p = bme280_p(up);
268 printf(
"T_BME280=%5.2f", (
double)bme280_mea.t_overscale100 / 100.);
269 printf(
" RH_BME280=%5.2f ", (
double)bme280_mea.h_overscale1024 / 1024.);
271 printf(
" P_BME280=%5.2f\n", (
double)bme280_mea.p_overscale256 / 256.);
273 printf(
" P_BME280=%5.2f\n", (
double)bme280_mea.p);
void clock_delay_usec(uint16_t dt)
Delay a given number of microseconds.
Definitions for the Bosch BME280 based on datasheet Rev 1.1