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bme280_math.c
357 lines (312 loc) · 14 KB
/
bme280_math.c
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// ***************************************************************************
// BMP280 module for ESP8266 with nodeMCU
//
// Written by Lukas Voborsky, @voborsky
//
// MIT license, http://opensource.org/licenses/MIT
// ***************************************************************************
// #define NODE_DEBUG
#include "module.h"
#include "lauxlib.h"
#include "platform.h"
#include "user_interface.h"
#include <math.h>
/****************************************************/
/**\name registers definition */
/***************************************************/
#define BME280_REGISTER_CONTROL (0xF4)
#define BME280_REGISTER_CONTROL_HUM (0xF2)
#define BME280_REGISTER_CONFIG (0xF5)
#define BME280_REGISTER_CHIPID (0xD0)
#define BME280_REGISTER_VERSION (0xD1)
#define BME280_REGISTER_SOFTRESET (0xE0)
#define BME280_REGISTER_CAL26 (0xE1)
#define BME280_REGISTER_PRESS (0xF7) // 0xF7-0xF9
#define BME280_REGISTER_TEMP (0xFA) // 0xFA-0xFC
#define BME280_REGISTER_HUM (0xFD) // 0xFD-0xFE
#define BME280_REGISTER_DIG_T (0x88) // 0x88-0x8D ( 6)
#define BME280_REGISTER_DIG_P (0x8E) // 0x8E-0x9F (18)
#define BME280_REGISTER_DIG_H1 (0xA1) // 0xA1 ( 1)
#define BME280_REGISTER_DIG_H2 (0xE1) // 0xE1-0xE7 ( 7)
/****************************************************/
/**\name I2C ADDRESS DEFINITIONS */
/***************************************************/
#define BME280_I2C_ADDRESS1 (0x76)
#define BME280_I2C_ADDRESS2 (0x77)
/****************************************************/
/**\name POWER MODE DEFINITIONS */
/***************************************************/
/* Sensor Specific constants */
#define BME280_SLEEP_MODE (0x00)
#define BME280_FORCED_MODE (0x01)
#define BME280_NORMAL_MODE (0x03)
#define BME280_SOFT_RESET_CODE (0xB6)
/****************************************************/
/**\name OVER SAMPLING DEFINITIONS */
/***************************************************/
#define BME280_OVERSAMP_1X (0x01)
#define BME280_OVERSAMP_2X (0x02)
#define BME280_OVERSAMP_4X (0x03)
#define BME280_OVERSAMP_8X (0x04)
#define BME280_OVERSAMP_16X (0x05)
/****************************************************/
/**\name STANDBY TIME DEFINITIONS */
/***************************************************/
#define BME280_STANDBY_TIME_1_MS (0x00)
#define BME280_STANDBY_TIME_63_MS (0x01)
#define BME280_STANDBY_TIME_125_MS (0x02)
#define BME280_STANDBY_TIME_250_MS (0x03)
#define BME280_STANDBY_TIME_500_MS (0x04)
#define BME280_STANDBY_TIME_1000_MS (0x05)
#define BME280_STANDBY_TIME_10_MS (0x06)
#define BME280_STANDBY_TIME_20_MS (0x07)
/****************************************************/
/**\name FILTER DEFINITIONS */
/***************************************************/
#define BME280_FILTER_COEFF_OFF (0x00)
#define BME280_FILTER_COEFF_2 (0x01)
#define BME280_FILTER_COEFF_4 (0x02)
#define BME280_FILTER_COEFF_8 (0x03)
#define BME280_FILTER_COEFF_16 (0x04)
/****************************************************/
/**\data type definition */
/***************************************************/
#define BME280_S32_t int32_t
#define BME280_U32_t uint32_t
#define BME280_S64_t int64_t
#define BME280_SAMPLING_DELAY 113 //maximum measurement time in ms for maximum oversampling for all measures = 1.25 + 2.3*16 + 2.3*16 + 0.575 + 2.3*16 + 0.575 ms
// #define r16s(reg) ((int16_t)r16u(reg))
// #define r16sLE(reg) ((int16_t)r16uLE(reg))
// #define bme280_adc_P(void) r24u(BME280_REGISTER_PRESS)
// #define bme280_adc_T(void) r24u(BME280_REGISTER_TEMP)
// #define bme280_adc_H(void) r16u(BME280_REGISTER_HUM)
typedef struct {
uint16_t dig_T1;
int16_t dig_T2;
int16_t dig_T3;
uint16_t dig_P1;
int16_t dig_P2;
int16_t dig_P3;
int16_t dig_P4;
int16_t dig_P5;
int16_t dig_P6;
int16_t dig_P7;
int16_t dig_P8;
int16_t dig_P9;
uint8_t dig_H1;
int16_t dig_H2;
uint8_t dig_H3;
int16_t dig_H4;
int16_t dig_H5;
int8_t dig_H6;
} bme280_data_t;
typedef bme280_data_t* bme280_data_p;
bme280_data_p bme280_data;
BME280_S32_t bme280_t_fine;
// Returns temperature in DegC, resolution is 0.01 DegC. Output value of “5123” equals 51.23 DegC.
// t_fine carries fine temperature as global value
BME280_S32_t bme280_compensate_T(BME280_S32_t adc_T) {
BME280_S32_t var1, var2, T;
var1 = ((((adc_T>>3) - ((BME280_S32_t)(*bme280_data).dig_T1<<1))) * ((BME280_S32_t)(*bme280_data).dig_T2)) >> 11;
var2 = (((((adc_T>>4) - ((BME280_S32_t)(*bme280_data).dig_T1)) * ((adc_T>>4) - ((BME280_S32_t)(*bme280_data).dig_T1))) >> 12) *
((BME280_S32_t)(*bme280_data).dig_T3)) >> 14;
bme280_t_fine = var1 + var2;
T = (bme280_t_fine * 5 + 128) >> 8;
return T;
}
// Returns pressure in Pa as unsigned 32 bit integer in Q24.8 format (24 integer bits and 8 fractional bits).
// Output value of “24674867” represents 24674867/256 = 96386.2 Pa = 963.862 hPa
BME280_U32_t bme280_compensate_P(BME280_S32_t adc_P) {
BME280_S64_t var1, var2, p;
var1 = ((BME280_S64_t)bme280_t_fine) - 128000;
var2 = var1 * var1 * (BME280_S64_t)(*bme280_data).dig_P6;
var2 = var2 + ((var1*(BME280_S64_t)(*bme280_data).dig_P5)<<17);
var2 = var2 + (((BME280_S64_t)(*bme280_data).dig_P4)<<35);
var1 = ((var1 * var1 * (BME280_S64_t)(*bme280_data).dig_P3)>>8) + ((var1 * (BME280_S64_t)(*bme280_data).dig_P2)<<12);
var1 = (((((BME280_S64_t)1)<<47)+var1))*((BME280_S64_t)(*bme280_data).dig_P1)>>33;
if (var1 == 0) {
return 0; // avoid exception caused by division by zero
}
p = 1048576-adc_P;
p = (((p<<31)-var2)*3125)/var1;
var1 = (((BME280_S64_t)(*bme280_data).dig_P9) * (p>>13) * (p>>13)) >> 25;
var2 = (((BME280_S64_t)(*bme280_data).dig_P8) * p) >> 19;
p = ((p + var1 + var2) >> 8) + (((BME280_S64_t)(*bme280_data).dig_P7)<<4);
p = (p * 10) >> 8;
return (BME280_U32_t)p;
}
// Returns humidity in %RH as unsigned 32 bit integer in Q22.10 format (22 integer and 10 fractional bits).
// Output value of “47445” represents 47445/1024 = 46.333 %RH
BME280_U32_t bme280_compensate_H(BME280_S32_t adc_H) {
BME280_S32_t v_x1_u32r;
v_x1_u32r = (bme280_t_fine - ((BME280_S32_t)76800));
v_x1_u32r = (((((adc_H << 14) - (((BME280_S32_t)(*bme280_data).dig_H4) << 20) - (((BME280_S32_t)(*bme280_data).dig_H5) * v_x1_u32r)) +
((BME280_S32_t)16384)) >> 15) * (((((((v_x1_u32r * ((BME280_S32_t)(*bme280_data).dig_H6)) >> 10) * (((v_x1_u32r *
((BME280_S32_t)(*bme280_data).dig_H3)) >> 11) + ((BME280_S32_t)32768))) >> 10) + ((BME280_S32_t)2097152)) *
((BME280_S32_t)(*bme280_data).dig_H2) + 8192) >> 14));
v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((BME280_S32_t)(*bme280_data).dig_H1)) >> 4));
v_x1_u32r = (v_x1_u32r < 0 ? 0 : v_x1_u32r);
v_x1_u32r = (v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r);
v_x1_u32r = v_x1_u32r>>12;
return (BME280_U32_t)((v_x1_u32r * 1000)>>10);
}
double ln(double x) {
double y = (x-1)/(x+1);
double y2 = y*y;
double r = 0;
for (int8_t i=33; i>0; i-=2) { //we've got the power
r = 1.0/(double)i + y2 * r;
}
return 2*y*r;
}
uint32_t bme280_h = 0; // buffer last qfe2qnh calculation
double bme280_hc = 1.0;
double bme280_qfe2qnh(double qfe, double h) {
double hc;
if (bme280_h == h) {
hc = bme280_hc;
} else {
hc = pow((double)(1.0 - 2.25577e-5 * h), (double)(-5.25588));
bme280_hc = hc; bme280_h = h;
}
double qnh = (double)qfe * hc;
return qnh;
}
int bme280_lua_setup(lua_State* L) {
uint8_t bme280_mode = 0; // stores oversampling settings
uint8_t bme280_ossh = 0; // stores humidity oversampling settings
uint8_t config;
uint8_t const bit3 = 0b111;
uint8_t const bit2 = 0b11;
bme280_mode = (!lua_isnumber(L, 5)?BME280_NORMAL_MODE:(luaL_checkinteger(L, 5)&bit2)) // 4-th parameter: power mode
| ((!lua_isnumber(L, 3)?BME280_OVERSAMP_16X:(luaL_checkinteger(L, 3)&bit3)) << 2) // 2-nd parameter: pressure oversampling
| ((!lua_isnumber(L, 2)?BME280_OVERSAMP_16X:(luaL_checkinteger(L, 2)&bit3)) << 5); // 1-st parameter: temperature oversampling
bme280_ossh = (!lua_isnumber(L, 4))?BME280_OVERSAMP_16X:(luaL_checkinteger(L, 4)&bit3); // 3-rd parameter: humidity oversampling
config = ((!lua_isnumber(L, 6)?BME280_STANDBY_TIME_20_MS:(luaL_checkinteger(L, 6)&bit3))<< 5) // 5-th parameter: inactive duration in normal mode
| ((!lua_isnumber(L, 7)?BME280_FILTER_COEFF_16:(luaL_checkinteger(L, 7)&bit3)) << 2); // 6-th parameter: IIR filter
// NODE_DBG("mode: %x\nhumidity oss: %x\nconfig: %x\n", bme280_mode, bme280_ossh, config);
#define r16uLE_buf(reg) (uint16_t)((reg[1] << 8) | reg[0])
#define r16sLE_buf(reg) (int16_t)(r16uLE_buf(reg))
size_t reg_len;
const char *buf = luaL_checklstring(L, 1, ®_len);
bme280_data = (bme280_data_p) memset(lua_newuserdata(L, sizeof(*bme280_data)), 0, sizeof(*bme280_data)); // first parameter to be returned
const uint8_t *reg;
reg = buf;
(*bme280_data).dig_T1 = r16uLE_buf(reg); reg+=2;
(*bme280_data).dig_T2 = r16sLE_buf(reg); reg+=2;
(*bme280_data).dig_T3 = r16sLE_buf(reg); reg+=2;
// NODE_DBG("dig_T: %d\t%d\t%d\n", (*bme280_data).dig_T1, (*bme280_data).dig_T2, (*bme280_data).dig_T3);
(*bme280_data).dig_P1 = r16uLE_buf(reg); reg+=2;
(*bme280_data).dig_P2 = r16sLE_buf(reg); reg+=2;
(*bme280_data).dig_P3 = r16sLE_buf(reg); reg+=2;
(*bme280_data).dig_P4 = r16sLE_buf(reg); reg+=2;
(*bme280_data).dig_P5 = r16sLE_buf(reg); reg+=2;
(*bme280_data).dig_P6 = r16sLE_buf(reg); reg+=2;
(*bme280_data).dig_P7 = r16sLE_buf(reg); reg+=2;
(*bme280_data).dig_P8 = r16sLE_buf(reg); reg+=2;
(*bme280_data).dig_P9 = r16sLE_buf(reg); reg+=2;
// NODE_DBG("dig_P: %d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n", (*bme280_data).dig_P1, (*bme280_data).dig_P2,(*bme280_data).dig_P3, (*bme280_data).dig_P4, (*bme280_data).dig_P5, (*bme280_data).dig_P6, (*bme280_data).dig_P7,(*bme280_data).dig_P8, (*bme280_data).dig_P9);
if (reg_len>=6+18) { // is BME?
(*bme280_data).dig_H1 = (uint8)reg[0]; reg+=1;
(*bme280_data).dig_H2 = r16sLE_buf(reg); reg+=2;
(*bme280_data).dig_H3 = reg[0]; reg++;
(*bme280_data).dig_H4 = (int16_t)reg[0] << 4 | (reg[1] & 0x0F); reg+=1; // H4[11:4 3:0] = 0xE4[7:0] 0xE5[3:0] 12-bit signed
(*bme280_data).dig_H5 = (int16_t)reg[1] << 4 | (reg[0] >> 4); reg+=2; // H5[11:4 3:0] = 0xE6[7:0] 0xE5[7:4] 12-bit signed
(*bme280_data).dig_H6 = (int8_t)reg[0];
NODE_DBG("dig_H: %d\t%d\t%d\t%d\t%d\t%d\n", (*bme280_data).dig_H1, (*bme280_data).dig_H2, (*bme280_data).dig_H3, (*bme280_data).dig_H4, (*bme280_data).dig_H5, (*bme280_data).dig_H6);
}
#undef r16uLE_buf
#undef r16sLE_buf
int i = 1;
char cfg[2]={'\0', '\0'};
lua_createtable(L, 3, 0); /* configuration table */
cfg[0]=(char)config;
lua_pushstring(L, cfg);
lua_rawseti(L, -2, i++);
cfg[0]=(char)bme280_ossh;
lua_pushstring(L, cfg);
lua_rawseti(L, -2, i++);
cfg[0]=(char)bme280_mode;
lua_pushstring(L, cfg);
lua_rawseti(L, -2, i);
return 2;
}
// Return T, QFE, H if no altitude given
// Return T, QFE, H, QNH if altitude given
int bme280_lua_read(lua_State* L) {
double qfe;
bme280_data = (bme280_data_p)lua_touserdata(L, 1);
size_t reg_len;
const char *buf = luaL_checklstring(L, 2, ®_len); // registers are P[3], T[3], H[2]
if (reg_len != 8 && reg_len !=6) {
luaL_error(L, "invalid readout data");
}
uint8_t calc_qnh = lua_isnumber(L, 3);
// Must do Temp first since bme280_t_fine is used by the other compensation functions
uint32_t adc_T = (uint32_t)(((buf[3] << 16) | (buf[4] << 8) | buf[5]) >> 4);
if (adc_T == 0x80000 || adc_T == 0xfffff)
return 0;
lua_pushnumber(L, bme280_compensate_T(adc_T)/100.0);
uint32_t adc_P = (uint32_t)(((buf[0] << 16) | (buf[1] << 8) | buf[2]) >> 4);
NODE_DBG("adc_P: %d\n", adc_P);
if (adc_P ==0x80000 || adc_P == 0xfffff) {
lua_pushnil(L);
calc_qnh = 0;
} else {
qfe = bme280_compensate_P(adc_P)/1000.0;
lua_pushnumber (L, qfe);
}
uint32_t adc_H = (uint32_t)((buf[6] << 8) | buf[7]);
if (reg_len!=8 || adc_H == 0x8000 || adc_H == 0xffff)
lua_pushnil(L);
else
lua_pushnumber (L, bme280_compensate_H(adc_H)/1000.0);
if (calc_qnh) { // have altitude
int32_t h = luaL_checknumber(L, 3);
double qnh = bme280_qfe2qnh(qfe, h);
lua_pushnumber (L, qnh);
return 4;
}
return 3;
}
int bme280_lua_qfe2qnh(lua_State* L) {
if (lua_isuserdata(L, 1) || lua_istable(L, 1)) { // allow to call it as object method, userdata have no use here
lua_remove(L, 1);
}
double qfe = luaL_checknumber(L, 1);
double h = luaL_checknumber(L, 2);
double qnh = bme280_qfe2qnh(qfe, h);
lua_pushnumber(L, qnh);
return 1;
}
int bme280_lua_altitude(lua_State* L) {
if (lua_isuserdata(L, 1) || lua_istable(L, 1)) { // allow to call it as object method, userdata have no use here
lua_remove(L, 1);
}
double P = luaL_checknumber(L, 1);
double qnh = luaL_checknumber(L, 2);
double h = (1.0 - pow((double)P/(double)qnh, 1.0/5.25588)) / 2.25577e-5;
lua_pushnumber (L, h);
return 1;
}
int bme280_lua_dewpoint(lua_State* L) {
if (lua_isuserdata(L, 1) || lua_istable(L, 1)) { // allow to call it as object method, userdata have no use here
lua_remove(L, 1);
}
double H = luaL_checknumber(L, 1)/100.0; // percent
double T = luaL_checknumber(L, 2);
const double c243 = 243.5;
const double c17 = 17.67;
double c = ln(H) + ((c17 * T) / (c243 + T));
double d = (c243 * c)/(c17 - c);
lua_pushnumber (L, d);
return 1;
}
LROT_BEGIN(bme280_math, NULL, 0)
LROT_FUNCENTRY( setup, bme280_lua_setup )
LROT_FUNCENTRY( read, bme280_lua_read )
LROT_FUNCENTRY( qfe2qnh, bme280_lua_qfe2qnh )
LROT_FUNCENTRY( altitude, bme280_lua_altitude )
LROT_FUNCENTRY( dewpoint, bme280_lua_dewpoint )
LROT_END(bme280_math, NULL, 0)
NODEMCU_MODULE(BME280_MATH, "bme280_math", bme280_math, NULL);