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Heltec-Aaron-LeeHeltec-Aaron-Lee
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Add BMP180 sensor example
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‎examples/Sensor/BMP180basic/BMP180basic.ino‎

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/* Heltec Automation BMP180 Sensors test example
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*
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* Function:
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* Temperature and Pressure measurement
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*
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* HelTec AutoMation, Chengdu, China
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* www.heltec.org
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*
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* this project also realess in GitHub:
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* https://github.com/HelTecAutomation/ASR650x-Arduino
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*
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*/
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#include "Arduino.h"
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#include "heltec.h"
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#include <Wire.h>
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#include <BMP180.h>
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#include "string.h"
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BMP085 bmp;
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uint8_t T[20] = {"Temperature"};
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void setup() {
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pinMode(Vext,OUTPUT);
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digitalWrite(Vext,LOW);
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Serial.begin(115200);
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}
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void drawFontFaceDemo(double T,double P,double A,double R) {
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Heltec.begin(true /*DisplayEnable Enable*/, false /*LoRa Disable*/, true /*Serial Enable*/);
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// Heltec.display->flipScreenVertically();
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Heltec.display->clear();
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Heltec.display->setTextAlignment(TEXT_ALIGN_LEFT);
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Heltec.display->setFont(ArialMT_Plain_10);
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Heltec.display->drawString(0 , 0 , "Temperature =");
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Heltec.display->drawString(76 , 0 , (String)T);
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Heltec.display->drawString(106 , 0 , " *C");
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Heltec.display->drawString(0 , 16 , "Pressure =");
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Heltec.display->drawString(56 , 16 , (String)P);
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Heltec.display->drawString(100 , 16 , "Pa");
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Heltec.display->drawString(0 , 32 , "Altitude =");
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Heltec.display->drawString(56 , 32 , (String)A);
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Heltec.display->drawString(86 , 32 , " m");
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Heltec.display->drawString(0 , 48 , "Real altitude =");
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Heltec.display->drawString(76 , 48 , (String)R);
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Heltec.display->drawString(106 , 48 , " m");
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Heltec.display->display();
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}
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void loop() {
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if (!bmp.begin()) {
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Serial.println("Could not find a valid BMP085 sensor, check wiring!");
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while (1) {}
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}
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double T =bmp.readTemperature();
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Serial.print("Temperature = ");
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Serial.print(T);
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Serial.println(" *C");
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double P = bmp.readPressure();
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Serial.print("Pressure = ");
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Serial.print(bmp.readPressure());
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Serial.println(" Pa");
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double A = bmp.readAltitude();
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// Calculate altitude assuming 'standard' barometric
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// pressure of 1013.25 millibar = 101325 Pascal
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Serial.print("Altitude = ");
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Serial.print(bmp.readAltitude());
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Serial.println(" meters");
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Serial.print("Pressure at sealevel (calculated) = ");
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Serial.print(bmp.readSealevelPressure());
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Serial.println(" Pa");
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double R = bmp.readAltitude(101500);
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// you can get a more precise measurement of altitude
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// if you know the current sea level pressure which will
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// vary with weather and such. If it is 1015 millibars
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// that is equal to 101500 Pascals.
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Serial.print("Real altitude = ");
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Serial.print(bmp.readAltitude(101500));
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Serial.println(" meters");
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Serial.println();
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delay(500);
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drawFontFaceDemo(T, P, A, R) ;
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delay(5000);
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}

‎src/BMP180.cpp‎

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#include "BMP180.h"
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BMP085::BMP085() {
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}
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boolean BMP085::begin(uint8_t mode) {
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if (mode > BMP085_ULTRAHIGHRES)
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mode = BMP085_ULTRAHIGHRES;
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oversampling = mode;
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//begin(int sdaPin, int sclPin, uint32_t frequency)
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Wire.begin(13, 12, 100000);
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if (read8(0xD0) != 0x55) return false;
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/* read calibration data */
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ac1 = read16(BMP085_CAL_AC1);
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ac2 = read16(BMP085_CAL_AC2);
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ac3 = read16(BMP085_CAL_AC3);
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ac4 = read16(BMP085_CAL_AC4);
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ac5 = read16(BMP085_CAL_AC5);
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ac6 = read16(BMP085_CAL_AC6);
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b1 = read16(BMP085_CAL_B1);
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b2 = read16(BMP085_CAL_B2);
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mb = read16(BMP085_CAL_MB);
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mc = read16(BMP085_CAL_MC);
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md = read16(BMP085_CAL_MD);
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#if (BMP085_DEBUG == 1)
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Serial.print("ac1 = "); Serial.println(ac1, DEC);
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Serial.print("ac2 = "); Serial.println(ac2, DEC);
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Serial.print("ac3 = "); Serial.println(ac3, DEC);
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Serial.print("ac4 = "); Serial.println(ac4, DEC);
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Serial.print("ac5 = "); Serial.println(ac5, DEC);
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Serial.print("ac6 = "); Serial.println(ac6, DEC);
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Serial.print("b1 = "); Serial.println(b1, DEC);
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Serial.print("b2 = "); Serial.println(b2, DEC);
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Serial.print("mb = "); Serial.println(mb, DEC);
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Serial.print("mc = "); Serial.println(mc, DEC);
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Serial.print("md = "); Serial.println(md, DEC);
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#endif
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return true;
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}
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int32_t BMP085::computeB5(int32_t UT) {
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int32_t X1 = (UT - (int32_t)ac6) * ((int32_t)ac5) >> 15;
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int32_t X2 = ((int32_t)mc << 11) / (X1+(int32_t)md);
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return X1 + X2;
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}
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uint16_t BMP085::readRawTemperature(void) {
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write8(BMP085_CONTROL, BMP085_READTEMPCMD);
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delay(5);
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#if BMP085_DEBUG == 1
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Serial.print("Raw temp: "); Serial.println(read16(BMP085_TEMPDATA));
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#endif
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return read16(BMP085_TEMPDATA);
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}
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uint32_t BMP085::readRawPressure(void) {
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uint32_t raw;
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write8(BMP085_CONTROL, BMP085_READPRESSURECMD + (oversampling << 6));
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if (oversampling == BMP085_ULTRALOWPOWER)
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delay(5);
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else if (oversampling == BMP085_STANDARD)
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delay(8);
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else if (oversampling == BMP085_HIGHRES)
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delay(14);
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else
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delay(26);
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raw = read16(BMP085_PRESSUREDATA);
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raw <<= 8;
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raw |= read8(BMP085_PRESSUREDATA+2);
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raw >>= (8 - oversampling);
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/* this pull broke stuff, look at it later?
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if (oversampling==0) {
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raw <<= 8;
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raw |= read8(BMP085_PRESSUREDATA+2);
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raw >>= (8 - oversampling);
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}
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*/
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#if BMP085_DEBUG == 1
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Serial.print("Raw pressure: "); Serial.println(raw);
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#endif
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return raw;
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}
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int32_t BMP085::readPressure(void) {
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int32_t UT, UP, B3, B5, B6, X1, X2, X3, p;
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uint32_t B4, B7;
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UT = readRawTemperature();
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UP = readRawPressure();
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#if BMP085_DEBUG == 1
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// use datasheet numbers!
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UT = 27898;
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UP = 23843;
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ac6 = 23153;
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ac5 = 32757;
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mc = -8711;
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md = 2868;
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b1 = 6190;
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b2 = 4;
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ac3 = -14383;
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ac2 = -72;
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ac1 = 408;
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ac4 = 32741;
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oversampling = 0;
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#endif
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B5 = computeB5(UT);
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#if BMP085_DEBUG == 1
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Serial.print("X1 = "); Serial.println(X1);
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Serial.print("X2 = "); Serial.println(X2);
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Serial.print("B5 = "); Serial.println(B5);
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#endif
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// do pressure calcs
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B6 = B5 - 4000;
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X1 = ((int32_t)b2 * ( (B6 * B6)>>12 )) >> 11;
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X2 = ((int32_t)ac2 * B6) >> 11;
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X3 = X1 + X2;
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B3 = ((((int32_t)ac1*4 + X3) << oversampling) + 2) / 4;
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#if BMP085_DEBUG == 1
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Serial.print("B6 = "); Serial.println(B6);
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Serial.print("X1 = "); Serial.println(X1);
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Serial.print("X2 = "); Serial.println(X2);
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Serial.print("B3 = "); Serial.println(B3);
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#endif
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X1 = ((int32_t)ac3 * B6) >> 13;
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X2 = ((int32_t)b1 * ((B6 * B6) >> 12)) >> 16;
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X3 = ((X1 + X2) + 2) >> 2;
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B4 = ((uint32_t)ac4 * (uint32_t)(X3 + 32768)) >> 15;
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B7 = ((uint32_t)UP - B3) * (uint32_t)( 50000UL >> oversampling );
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#if BMP085_DEBUG == 1
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Serial.print("X1 = "); Serial.println(X1);
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Serial.print("X2 = "); Serial.println(X2);
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Serial.print("B4 = "); Serial.println(B4);
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Serial.print("B7 = "); Serial.println(B7);
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#endif
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if (B7 < 0x80000000) {
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p = (B7 * 2) / B4;
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} else {
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p = (B7 / B4) * 2;
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}
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X1 = (p >> 8) * (p >> 8);
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X1 = (X1 * 3038) >> 16;
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X2 = (-7357 * p) >> 16;
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#if BMP085_DEBUG == 1
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Serial.print("p = "); Serial.println(p);
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Serial.print("X1 = "); Serial.println(X1);
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Serial.print("X2 = "); Serial.println(X2);
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#endif
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p = p + ((X1 + X2 + (int32_t)3791)>>4);
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#if BMP085_DEBUG == 1
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Serial.print("p = "); Serial.println(p);
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#endif
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return p;
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}
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int32_t BMP085::readSealevelPressure(float altitude_meters) {
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float pressure = readPressure();
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return (int32_t)(pressure / pow(1.0-altitude_meters/44330, 5.255));
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}
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float BMP085::readTemperature(void) {
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int32_t UT, B5; // following ds convention
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float temp;
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UT = readRawTemperature();
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#if BMP085_DEBUG == 1
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// use datasheet numbers!
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UT = 27898;
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ac6 = 23153;
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ac5 = 32757;
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mc = -8711;
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md = 2868;
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#endif
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B5 = computeB5(UT);
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temp = (B5+8) >> 4;
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temp /= 10;
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return temp;
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}
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float BMP085::readAltitude(float sealevelPressure) {
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float altitude;
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float pressure = readPressure();
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altitude = 44330 * (1.0 - pow(pressure /sealevelPressure,0.1903));
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return altitude;
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}
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/*********************************************************************/
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uint8_t BMP085::read8(uint8_t a) {
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uint8_t ret;
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Wire.beginTransmission(BMP085_I2CADDR); // start transmission to device
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Wire.write(a); // sends register address to read from
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Wire.endTransmission(); // end transmission
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Wire.beginTransmission(BMP085_I2CADDR); // start transmission to device
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Wire.requestFrom(BMP085_I2CADDR, 1);// send data n-bytes read
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ret = Wire.read(); // receive DATA
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Wire.endTransmission(); // end transmission
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return ret;
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}
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uint16_t BMP085::read16(uint8_t a) {
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uint16_t ret;
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Wire.beginTransmission(BMP085_I2CADDR); // start transmission to device
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Wire.write(a); // sends register address to read from
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Wire.endTransmission(); // end transmission
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Wire.beginTransmission(BMP085_I2CADDR); // start transmission to device
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Wire.requestFrom(BMP085_I2CADDR, 2);// send data n-bytes read
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ret = Wire.read(); // receive DATA
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ret <<= 8;
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ret |= Wire.read(); // receive DATA
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Wire.endTransmission(); // end transmission
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return ret;
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}
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void BMP085::write8(uint8_t a, uint8_t d) {
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Wire.beginTransmission(BMP085_I2CADDR); // start transmission to device
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Wire.write(a); // sends register address to read from
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Wire.write(d); // write data
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Wire.endTransmission(); // end transmission
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}

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