主処理の部分だけを簡単に見ておきましょう。
初期化処理setupでは、シリアルモニターとI2Cインターフェイスの初期化を行い、BME280とBH1750を初期化しています。続いて計測メソッドdoMeasurementを実行。これは起動直後の計測で、不安定な計測値の取得を回避するためのダミー処理です。
反復処理loopでは、計測を実行するためにdoMeasurementメソッドを呼び、editMeasuredResultで編集結果をシリアルモニターに表示するだけです。
/*
* File: espI2C.ino
* Function: Measure temperature, humidity, atmospheric pressure and illuminance.
* Date: 2017/01/18
* Author: Marchan
*
* Hardware MCU: ESP-WROOM-02(ESP8266)
* RTC: DS1307 I2C Real time clock module.
* + Combined humidity and pressure sensor: BME280
* + Digital illuminance sensor: BH1750
*
* Remarks: Code for measurement and calibration of 'BME 280' uses
* SWITCH SCIENCE sample sketch(BME280_I2C.zip).
* https://www.switch-science.com//catalog/2236/
*/
#include <Wire.h>
// I2C Address
#define DS1307_ADDRESS 0x68 // Realtime clock
#define BME280_ADDRESS 0x76 // Humidity, Pressure and Temperature sensor
#define BH1750_ADDRESS 0x23 // Illuminance sensor
const String strTitle = "Temp(C), Press(hPa), Hum(%), Illum(lx), Date Time";
// DS1307 Clock data
struct ClockData {
byte year;
byte month;
byte day;
byte week;
byte hour;
byte minute;
byte sec;
byte ctrl;
};
ClockData dtClock;
//BME280 Global variables
unsigned long int hum_raw, temp_raw, pres_raw;
signed long int t_fine;
//BME280 Calibration variables
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;
int8_t dig_H1;
int16_t dig_H2;
int8_t dig_H3;
int16_t dig_H4;
int16_t dig_H5;
int8_t dig_H6;
//Measured result
struct MeasuredResult {
double temperature;
double pressure;
double humidity;
int illuminance;
String datetime;
};
MeasuredResult rstMeasured;
/*****************************************************************************
* Predetermined Sequence *
*****************************************************************************/
void setup() {
Serial.begin(115200);
// Prepare I2C protocol.
Wire.begin();
// Prepare measurment
prepareBME280(); // Humidity, Pressure and Temperature sensor
delay(500);
prepareBH1750(BH1750_ADDRESS); // Illuminance sensor
// Dummy measurement
doMeasurement();
delay(100);
Serial.println("");
Serial.println(strTitle);
}
void loop() {
// Measurment
doMeasurement();
// Display measured result.
Serial.println(editMeasuredResult(rstMeasured));
delay(1000);
}
/*****************************************************************************/
/*
* Measure and calibrate BME280, also illuminance
* Result stored into rstMeasured structure.
*/
void doMeasurement()
{
// Read BME280 measured result
readData();
// Calibration
long temp_cal = calibration_T(temp_raw);
long press_cal = calibration_P(pres_raw);
long hum_cal = calibration_H(hum_raw);
// Measurement illuminance
int val = measureIlluminance(BH1750_ADDRESS);
// Get date and time data from DS1307
getDateTime(&dtClock);
//Store into measured resut structure
rstMeasured.temperature = (double)temp_cal / 100.0;
rstMeasured.pressure = (double)press_cal / 100.0;
rstMeasured.humidity = (double)hum_cal / 1024.0;
rstMeasured.illuminance = (int)val;
rstMeasured.datetime = editDateTime(dtClock);
}
/*
* Edit measured result data.
* Argument: (struct)Measured result.
* Return: Edited result.
*/
String editMeasuredResult(MeasuredResult data)
{
char wbuf[20];
String strWork = "";
printNum(wbuf, data.temperature, 4, 1);
strWork.concat(wbuf);
strWork.concat(",");
printNum(wbuf, data.pressure, 7, 1);
strWork.concat(wbuf);
strWork.concat(",");
printNum(wbuf, data.humidity, 5, 1);
strWork.concat(wbuf);
strWork.concat(",");
printNum(wbuf, data.illuminance, 6);
strWork.concat(wbuf);
strWork.concat(", ");
strWork.concat(data.datetime);
return strWork;
}
/*
* Print numeric (double, float)
* Argument: char* buffer, double data, int edit-length, int decimal.
*/
char *printNum(char *buf, double field, int len, int decimal)
{
*buf ='\0';
char bufw[40];
dtostrf(field, len, decimal, bufw);
strcpy(buf, bufw);
return buf;
}
/*
* Print numeric (int, long)
* Argument: char* buffer, int data, int edit-length.
*/
char *printNum(char *buf, int field, int len)
{
*buf = '\0';
char bufw[40];
sprintf(bufw, "%d", field);
int lenw = strlen(bufw);
int i;
for (i = 0; i < len - lenw; i++) {
*(buf + i) = ' ';
}
*(buf + i) = '\0';
strcat(buf, bufw);
return buf;
}
/* ======================== DS1307 Clock Control ============================*/
/*
* Read data from DS1307 Register
*/
void getDateTime(ClockData *dt)
{
int iValue = 0;
Wire.beginTransmission(DS1307_ADDRESS);
Wire.write(iValue);
Wire.endTransmission();
Wire.requestFrom(DS1307_ADDRESS, 7);
dt->sec = Wire.read();
dt->minute = Wire.read();
dt->hour = Wire.read();
dt->week = Wire.read();
dt->day = Wire.read();
dt->month = Wire.read();
dt->year = Wire.read();
}
/*
* Tell day of week from code.
*/
String tellDayOfWeek(byte num)
{
static String week[] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
if (num >= 1 && num <= 7)
return week[num-1];
else
return "";
}
/*
* Set DS1307 time register.
* Argument: (String)Time string 'hh:mm:ss'.
*/
void setTime(String sTime)
{
byte bValue = 0x00; //Top Address
String buf = sTime;
buf.replace(":", ""); buf.trim();
if (buf.length() == 6) {
byte hour = (buf.charAt(0) << 4) + (buf.charAt(1) & 0x0f);
byte minute = (buf.charAt(2) << 4) + (buf.charAt(3) & 0x0f);
byte sec = (buf.charAt(4) << 4) + (buf.charAt(5) & 0x0f);
Wire.beginTransmission(DS1307_ADDRESS);
Wire.write(bValue);
Wire.write(sec);
Wire.write(minute);
Wire.write(hour);
Wire.endTransmission();
}
}
/*
* Set DS1307 date register.
* Argument: (String)Time string 'yy/mm/dd/w'.
*/
void setDate(String sDate)
{
byte bValue = 0x03; //Top Address
String buf = sDate;
buf.replace("/", ""); buf.trim();
if (buf.length() >= 6) {
byte year = (buf.charAt(0) << 4) + (buf.charAt(1) & 0x0f);
byte month = (buf.charAt(2) << 4) + (buf.charAt(3) & 0x0f);
byte day = (buf.charAt(4) << 4) + (buf.charAt(5) & 0x0f);
byte week;
if (buf.length() == 7) {
week = (buf.charAt(6) & 0x07);
if (week < 0x01 || week > 0x07)
week = 0x01;
}
Wire.beginTransmission(DS1307_ADDRESS);
Wire.write(bValue);
Wire.write(week);
Wire.write(day);
Wire.write(month);
Wire.write(year);
Wire.endTransmission();
}
}
/*
* Edit DS1307 date and time.
*/
String editDateTime(ClockData dt)
{
return editDate(dt) + " " + editTime(dt);
}
/*
* Edit time register.
*/
String editTime(ClockData dt)
{
String buf = "";
char wbuf[12];
sprintf(wbuf, "%02x:%02x:%02x", (int)dt.hour, (int)dt.minute, (int)dt.sec);
buf.concat(wbuf);
return buf;
}
/*
* Edit date register.
*/
String editDate(ClockData dt)
{
String buf = "20";
char wbuf[12];
sprintf(wbuf, "%02x/%02x/%02x", (int)dt.year, (int)dt.month, (int)dt.day);
buf.concat(wbuf);
return buf;
}
/* ====================== BME280 T-P-H Measurement ==========================*/
/*
* Initiate BME280 and get calibration variables.
*/
void prepareBME280()
{
uint8_t osrs_t = 1; //Temperature oversampling x 1
uint8_t osrs_p = 1; //Pressure oversampling x 1
uint8_t osrs_h = 1; //Humidity oversampling x 1
uint8_t mode = 3; //Normal mode
uint8_t t_sb = 5; //Tstandby 1000ms
uint8_t filter = 0; //Filter off
uint8_t spi3w_en = 0; //3-wire SPI Disable
uint8_t ctrl_meas_reg = (osrs_t << 5) | (osrs_p << 2) | mode;
uint8_t config_reg = (t_sb << 5) | (filter << 2) | spi3w_en;
uint8_t ctrl_hum_reg = osrs_h;
writeReg(0xF2,ctrl_hum_reg);
writeReg(0xF4,ctrl_meas_reg);
writeReg(0xF5,config_reg);
readTrim();
}
/*
* Read calibration variables into structure.
*/
void readTrim()
{
uint8_t data[32],i=0;
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0x88);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,24);
while(Wire.available()){
data[i] = Wire.read();
i++;
}
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0xA1);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,1);
data[i] = Wire.read();
i++;
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0xE1);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,7);
while(Wire.available()){
data[i] = Wire.read();
i++;
}
dig_T1 = (data[1] << 8) | data[0];
dig_T2 = (data[3] << 8) | data[2];
dig_T3 = (data[5] << 8) | data[4];
dig_P1 = (data[7] << 8) | data[6];
dig_P2 = (data[9] << 8) | data[8];
dig_P3 = (data[11]<< 8) | data[10];
dig_P4 = (data[13]<< 8) | data[12];
dig_P5 = (data[15]<< 8) | data[14];
dig_P6 = (data[17]<< 8) | data[16];
dig_P7 = (data[19]<< 8) | data[18];
dig_P8 = (data[21]<< 8) | data[20];
dig_P9 = (data[23]<< 8) | data[22];
dig_H1 = data[24];
dig_H2 = (data[26]<< 8) | data[25];
dig_H3 = data[27];
dig_H4 = (data[28]<< 4) | (0x0F & data[29]);
dig_H5 = (data[30] << 4) | ((data[29] >> 4) & 0x0F);
dig_H6 = data[31];
}
/*
* Write data into BME280 register.
* Argument: (uint8_t)Register address, (uint8_t)data.
*/
void writeReg(uint8_t reg_address, uint8_t data)
{
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(reg_address);
Wire.write(data);
Wire.endTransmission();
}
/*
* Read data from BME280 register.
*/
void readData()
{
int i = 0;
uint32_t data[8];
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0xF7);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,8);
while(Wire.available()){
data[i] = Wire.read();
i++;
}
pres_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
temp_raw = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4);
hum_raw = (data[6] << 8) | data[7];
}
/*
* Calibration [Temperature]
*/
signed long int calibration_T(signed long int adc_T)
{
signed long int var1, var2, T;
var1 = ((((adc_T >> 3) - ((signed long int)dig_T1<<1))) * ((signed long int)dig_T2)) >> 11;
var2 = (((((adc_T >> 4) - ((signed long int)dig_T1)) * ((adc_T>>4) - ((signed long int)dig_T1))) >> 12) * ((signed long int)dig_T3)) >> 14;
t_fine = var1 + var2;
T = (t_fine * 5 + 128) >> 8;
return T;
}
/*
* Calibration [Pressure]
*/
unsigned long int calibration_P(signed long int adc_P)
{
signed long int var1, var2;
unsigned long int P;
var1 = (((signed long int)t_fine)>>1) - (signed long int)64000;
var2 = (((var1>>2) * (var1>>2)) >> 11) * ((signed long int)dig_P6);
var2 = var2 + ((var1*((signed long int)dig_P5))<<1);
var2 = (var2>>2)+(((signed long int)dig_P4)<<16);
var1 = (((dig_P3 * (((var1>>2)*(var1>>2)) >> 13)) >>3) + ((((signed long int)dig_P2) * var1)>>1))>>18;
var1 = ((((32768+var1))*((signed long int)dig_P1))>>15);
if (var1 == 0)
{
return 0;
}
P = (((unsigned long int)(((signed long int)1048576)-adc_P)-(var2>>12)))*3125;
if(P<0x80000000)
{
P = (P << 1) / ((unsigned long int) var1);
}
else
{
P = (P / (unsigned long int)var1) * 2;
}
var1 = (((signed long int)dig_P9) * ((signed long int)(((P>>3) * (P>>3))>>13)))>>12;
var2 = (((signed long int)(P>>2)) * ((signed long int)dig_P8))>>13;
P = (unsigned long int)((signed long int)P + ((var1 + var2 + dig_P7) >> 4));
return P;
}
/*
* Calibration [Humidity]
*/
unsigned long int calibration_H(signed long int adc_H)
{
signed long int v_x1;
v_x1 = (t_fine - ((signed long int)76800));
v_x1 = (((((adc_H << 14) -(((signed long int)dig_H4) << 20) - (((signed long int)dig_H5) * v_x1)) +
((signed long int)16384)) >> 15) * (((((((v_x1 * ((signed long int)dig_H6)) >> 10) *
(((v_x1 * ((signed long int)dig_H3)) >> 11) + ((signed long int) 32768))) >> 10) + (( signed long int)2097152)) *
((signed long int) dig_H2) + 8192) >> 14));
v_x1 = (v_x1 - (((((v_x1 >> 15) * (v_x1 >> 15)) >> 7) * ((signed long int)dig_H1)) >> 4));
v_x1 = (v_x1 < 0 ? 0 : v_x1);
v_x1 = (v_x1 > 419430400 ? 419430400 : v_x1);
return (unsigned long int)(v_x1 >> 12);
}
/* ========================= BH1750 Illuminance =============================*/
/*
* Initiate BH1750
*/
void prepareBH1750(int i2cAddress)
{
Wire.beginTransmission(i2cAddress);
Wire.write(0x10);
Wire.endTransmission();
delay(180);
}
/*
* Measure illuminance
*/
int measureIlluminance(int i2cAddress)
{
uint16_t val = 0;
byte buf[2];
if (measureIlluminance(i2cAddress, buf) == 2){
val = ((buf[0] << 8) | buf[1]) / 1.2; // Calculate
return (int)val;
}
return 0;
}
int measureIlluminance(int i2cAddress, byte *buff)
{
int i = 0;
*buff = 0x00;
Wire.beginTransmission(i2cAddress);
Wire.requestFrom(i2cAddress, 2);
while (Wire.available())
{
*(buff + i) = Wire.read();
i++;
}
Wire.endTransmission();
return i;
}
次回は、SDカードを増設してデータの記録を可能にします。合わせてアナログ入力センサーも増設、お楽しみに！
