Arduino Portable Weather Monitor, Altimeter, Temperature, Humidity, Using DHT11 and BMP85 With LCD Using Only 3 Pins
Intro: Arduino Portable Weather Monitor, Altimeter, Temperature, Humidity, Using DHT11 and BMP85 With LCD Using Only 3 Pins
I did this project because I often climb mountains like the one in the picture and I need to know the altitude, the temperature, and also changes in the weather, sometimes in just minutes the weather get very bad, with hail, snow and a very dense mist.
All you need are a DHT11 Sensor, a BMP085 barometric Sensor, a Serial enabled LCD and of course an arduino.
All you need are a DHT11 Sensor, a BMP085 barometric Sensor, a Serial enabled LCD and of course an arduino.
STEP 1: Step 1: Get the Parts
Materials:
1 Arduino
1 DHT11 Sensor (Temperature and Humidity Sensor)
1 BMP085 Sensor (Barometric Sensor) // Note: I have a GY-65 Modue it can handle 5v
1 Serial enabled LCD
1 10k resistor
1 Arduino
1 DHT11 Sensor (Temperature and Humidity Sensor)
1 BMP085 Sensor (Barometric Sensor) // Note: I have a GY-65 Modue it can handle 5v
1 Serial enabled LCD
1 10k resistor
STEP 2: Build the Circuit
1 Attach the BMP085 to Arduino
Arduino 5v Pin to VCC Pin on BMP085(Important!! some Modules only support 3.3 v!! use the 3.3v Pin instead!)
Arduino GND Pin to GND Pin on BMP085
Arduino A5 Pin to SCL Pin on BMP085 (Analog 5 Pin to Clock Pin)
Arduino A4 Pin to SDA Pin on BMP085(Analog 4 Pin to Data Pin)
2 Attach the DHT11 Sensor to Arduino
Arduino 5V Pin to VCC Pin on DHT11
Arduino GND Pin to GDN Pin on DHT11
Arduino Digital Pin 2 to Data Pin on DHT11 and 10k resistor to GND on Arduino
3 Attach the serial enabled LCD to Arduino
Arduino 5v Pin to VCC Pin on Serial enabled LCD
Arduino GND Pin to GND Pin on Serial enabled LCD
Now the tricky part we will use the same ports as the BMP085
Arduino A5 Pin to the same line of the breadboard on the SCL Pin on BMP085
Arduino A4 Pin to the same line of the breadboard on the SDA Pin on BMP085
Arduino 5v Pin to VCC Pin on BMP085(Important!! some Modules only support 3.3 v!! use the 3.3v Pin instead!)
Arduino GND Pin to GND Pin on BMP085
Arduino A5 Pin to SCL Pin on BMP085 (Analog 5 Pin to Clock Pin)
Arduino A4 Pin to SDA Pin on BMP085(Analog 4 Pin to Data Pin)
2 Attach the DHT11 Sensor to Arduino
Arduino 5V Pin to VCC Pin on DHT11
Arduino GND Pin to GDN Pin on DHT11
Arduino Digital Pin 2 to Data Pin on DHT11 and 10k resistor to GND on Arduino
3 Attach the serial enabled LCD to Arduino
Arduino 5v Pin to VCC Pin on Serial enabled LCD
Arduino GND Pin to GND Pin on Serial enabled LCD
Now the tricky part we will use the same ports as the BMP085
Arduino A5 Pin to the same line of the breadboard on the SCL Pin on BMP085
Arduino A4 Pin to the same line of the breadboard on the SDA Pin on BMP085
STEP 3: Upload the Code to the Arduino
/*Based largely on code by Jim Lindblom Get pressure, altitude, and temperature from the BMP085. Serial.print it out at 9600 baud to serial monitor. */ #include <dht11.h> #include <Wire.h> #include <LiquidCrystal_I2C.h> LiquidCrystal_I2C lcd(0x27,16,2); dht11 DHT11; #define DHT11PIN 2 #define BMP085_ADDRESS 0x77 // I2C address of BMP085 const unsigned char OSS = 0; // Oversampling Setting // Calibration values int ac1; int ac2; int ac3; unsigned int ac4; unsigned int ac5; unsigned int ac6; int b1; int b2; int mb; int mc; int md; // b5 is calculated in bmp085GetTemperature(...), this variable is also used in bmp085GetPressure(...) // so ...Temperature(...) must be called before ...Pressure(...). long b5; void setup(){ Serial.begin(9600); Wire.begin(); lcd.init(); // initialize the lcd lcd.backlight(); bmp085Calibration(); } void loop() { float temperature = bmp085GetTemperature(bmp085ReadUT()); //MUST be called first float pressure = bmp085GetPressure(bmp085ReadUP()); float atm = pressure / 101325; // "standard atmosphere" float altitude = calcAltitude(pressure); //Uncompensated caculation - in Meters Serial.println("\n"); int chk = DHT11.read(DHT11PIN); Serial.print("Read sensor: "); switch (chk) { case 0: Serial.println("OK"); break; case -1: Serial.println("Checksum error"); break; case -2: Serial.println("Time out error"); break; default: Serial.println("Unknown error"); break; } Serial.print("Humidity (%): "); Serial.println((float)DHT11.humidity, 2); Serial.print("Temperature (oC): "); Serial.println((float)DHT11.temperature, 2); lcd.print("Hum(%): "); lcd.print((float)DHT11.humidity, 2); lcd.setCursor(0,1); lcd.print("Temp(C): "); lcd.print((float)DHT11.temperature, 2); delay(2000); lcd.clear(); Serial.print("Temperature (oF): "); Serial.println(Fahrenheit(DHT11.temperature), 2); Serial.print("Temperature (K): "); Serial.println(Kelvin(DHT11.temperature), 2); lcd.print("Temp(F): "); lcd.print(Fahrenheit(DHT11.temperature), 2); lcd.setCursor(0,1); lcd.print("Temp(K): "); lcd.print(Kelvin(DHT11.temperature), 2); delay(3000); lcd.clear(); Serial.print("Dew Point (oC): "); Serial.println(dewPoint(DHT11.temperature, DHT11.humidity)); Serial.print("Dew PointFast (oC): "); Serial.println(dewPointFast(DHT11.temperature, DHT11.humidity)); lcd.print("DewP(C): "); lcd.print(dewPoint(DHT11.temperature, DHT11.humidity)); lcd.setCursor(0,1); lcd.print("DewPF(C): "); lcd.print(dewPointFast(DHT11.temperature, DHT11.humidity)); delay(3000); lcd.clear(); Serial.print("Temperature2: "); Serial.print(temperature, 2); //display 2 decimal places Serial.println("deg C"); Serial.print("Pressure: "); Serial.print(pressure, 0); //whole number only. Serial.println(" Pa"); lcd.print("Temp2: "); lcd.print(temperature, 2); //display 2 decimal places lcd.print(" C"); lcd.setCursor(0,1); lcd.print("Pres: "); lcd.print(pressure, 0); lcd.print(" PA"); delay(3000); lcd.clear(); Serial.print("Standard Atmosphere: "); Serial.println(atm, 4); //display 4 decimal places Serial.print("Altitude: "); Serial.print(altitude, 2); //display 2 decimal places Serial.println(" M"); lcd.print("Std Atm: "); lcd.print(atm, 4); //display 2 decimal places lcd.setCursor(0,1); lcd.print("Alt: "); lcd.print(altitude, 2); lcd.print(" M"); delay(3000); lcd.clear(); Serial.println();//line break delay(100); //wait a second and get values again. } /*-----( Declare User-written Functions )-----*/ // //Celsius to Fahrenheit conversion double Fahrenheit(double celsius) { return 1.8 * celsius + 32; } //Celsius to Kelvin conversion double Kelvin(double celsius) { return celsius + 273.15; } // dewPoint function NOAA // reference: http://wahiduddin.net/calc/density_algorithms.htm double dewPoint(double celsius, double humidity) { double A0= 373.15/(273.15 + celsius); double SUM = -7.90298 * (A0-1); SUM += 5.02808 * log10(A0); SUM += -1.3816e-7 * (pow(10, (11.344*(1-1/A0)))-1) ; SUM += 8.1328e-3 * (pow(10,(-3.49149*(A0-1)))-1) ; SUM += log10(1013.246); double VP = pow(10, SUM-3) * humidity; double T = log(VP/0.61078); // temp var return (241.88 * T) / (17.558-T); } // delta max = 0.6544 wrt dewPoint() // 5x faster than dewPoint() // reference: http://en.wikipedia.org/wiki/Dew_point double dewPointFast(double celsius, double humidity) { double a = 17.271; double b = 237.7; double temp = (a * celsius) / (b + celsius) + log(humidity/100); double Td = (b * temp) / (a - temp); return Td; } // Stores all of the bmp085's calibration values into global variables // Calibration values are required to calculate temp and pressure // This function should be called at the beginning of the program void bmp085Calibration() { ac1 = bmp085ReadInt(0xAA); ac2 = bmp085ReadInt(0xAC); ac3 = bmp085ReadInt(0xAE); ac4 = bmp085ReadInt(0xB0); ac5 = bmp085ReadInt(0xB2); ac6 = bmp085ReadInt(0xB4); b1 = bmp085ReadInt(0xB6); b2 = bmp085ReadInt(0xB8); mb = bmp085ReadInt(0xBA); mc = bmp085ReadInt(0xBC); md = bmp085ReadInt(0xBE); } // Calculate temperature in deg C float bmp085GetTemperature(unsigned int ut){ long x1, x2; x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15; x2 = ((long)mc << 11)/(x1 + md); b5 = x1 + x2; float temp = ((b5 + 8)>>4); temp = temp /10; return temp; } // Calculate pressure given up // calibration values must be known // b5 is also required so bmp085GetTemperature(...) must be called first. // Value returned will be pressure in units of Pa. long bmp085GetPressure(unsigned long up){ long x1, x2, x3, b3, b6, p; unsigned long b4, b7; b6 = b5 - 4000; // Calculate B3 x1 = (b2 * (b6 * b6)>>12)>>11; x2 = (ac2 * b6)>>11; x3 = x1 + x2; b3 = (((((long)ac1)*4 + x3)<>2; // Calculate B4 x1 = (ac3 * b6)>>13; x2 = (b1 * ((b6 * b6)>>12))>>16; x3 = ((x1 + x2) + 2)>>2; b4 = (ac4 * (unsigned long)(x3 + 32768))>>15; b7 = ((unsigned long)(up - b3) * (50000>>OSS)); if (b7 < 0x80000000) p = (b7<<1)/b4; else p = (b7/b4)<<1; x1 = (p>>8) * (p>>8); x1 = (x1 * 3038)>>16; x2 = (-7357 * p)>>16; p += (x1 + x2 + 3791)>>4; long temp = p; return temp; } // Read 1 byte from the BMP085 at 'address' char bmp085Read(unsigned char address) { unsigned char data; Wire.beginTransmission(BMP085_ADDRESS); Wire.write(address); Wire.endTransmission(); Wire.requestFrom(BMP085_ADDRESS, 1); while(!Wire.available()) ; return Wire.read(); } // Read 2 bytes from the BMP085 // First byte will be from 'address' // Second byte will be from 'address'+1 int bmp085ReadInt(unsigned char address) { unsigned char msb, lsb; Wire.beginTransmission(BMP085_ADDRESS); Wire.write(address); Wire.endTransmission(); Wire.requestFrom(BMP085_ADDRESS, 2); while(Wire.available()<2) ; msb = Wire.read(); lsb = Wire.read(); return (int) msb<<8 | lsb; } // Read the uncompensated temperature value unsigned int bmp085ReadUT(){ unsigned int ut; // Write 0x2E into Register 0xF4 // This requests a temperature reading Wire.beginTransmission(BMP085_ADDRESS); Wire.write(0xF4); Wire.write(0x2E); Wire.endTransmission(); // Wait at least 4.5ms delay(5); // Read two bytes from registers 0xF6 and 0xF7 ut = bmp085ReadInt(0xF6); return ut; } // Read the uncompensated pressure value unsigned long bmp085ReadUP(){ unsigned char msb, lsb, xlsb; unsigned long up = 0; // Write 0x34+(OSS<<6) into register 0xF4 // Request a pressure reading w/ oversampling setting Wire.beginTransmission(BMP085_ADDRESS); Wire.write(0xF4); Wire.write(0x34 + (OSS<<6)); Wire.endTransmission(); // Wait for conversion, delay time dependent on OSS delay(2 + (3<> (8-OSS); return up; } void writeRegister(int deviceAddress, byte address, byte val) { Wire.beginTransmission(deviceAddress); // start transmission to device Wire.write(address); // send register address Wire.write(val); // send value to write Wire.endTransmission(); // end transmission } int readRegister(int deviceAddress, byte address){ int v; Wire.beginTransmission(deviceAddress); Wire.write(address); // register to read Wire.endTransmission(); Wire.requestFrom(deviceAddress, 1); // read a byte while(!Wire.available()) { // waiting } v = Wire.read(); return v; } float calcAltitude(float pressure){ float A = pressure/101325; float B = 1/5.25588; float C = pow(A,B); C = 1 - C; C = C /0.0000225577; return C; }
STEP 4: Test the Code
Once you Upload the code you can watch in the screen:
1 Humidity %
2 Temperature Celsius (From the DHT11)
3 Temperature Farenheit
4 Temperature Kelvin
5 Dew Point
6 Dew Point Fast
7 Temperature 2 Celsius (From the BMP085)
8 Pressure in Pascals
9 Standard Atmosphere
10 Altitude in Meters
You can also see the same info if you use the Serial Monitor of your arduino IDE
1 Humidity %
2 Temperature Celsius (From the DHT11)
3 Temperature Farenheit
4 Temperature Kelvin
5 Dew Point
6 Dew Point Fast
7 Temperature 2 Celsius (From the BMP085)
8 Pressure in Pascals
9 Standard Atmosphere
10 Altitude in Meters
You can also see the same info if you use the Serial Monitor of your arduino IDE
STEP 5: Make It Portable
You can use a 9v battery or 5 AA NiH rechargeable batteries, solder a compatible plug for your arduino and then just find a case to protect your weather monitor, you can use a transparent tupperware case, or you can build yourself a plexiglass case,and you are ready to climb any mountain you want.
13 Comments
mohamadnurazam5 3 years ago
Razvan_ss 8 years ago
Hello! I am getting this error. Would you kindly take a look and give me an advice? Thank you!
sketch_jul24b.ino: In function 'long int bmp085GetPressure(long unsigned int)':
sketch_jul24b:234: error: expected primary-expression before '>' token
sketch_jul24b:234: error: expected ')' before ';' token
sketch_jul24b:234: error: expected ')' before ';' token
sketch_jul24b.ino: In function 'long unsigned int bmp085ReadUP()':
sketch_jul24b:326: error: expected primary-expression before '>' token
sketch_jul24b:326: error: expected ')' before ';' token
expected primary-expression before '>' token
WayanN 9 years ago
hello, can you help me please?
i found this error, what should i do?
sketch_jan16a:14: error: 'dht11' does not name a type
sketch_jan16a.ino: In function 'void loop()':
sketch_jan16a:57: error: 'DHT11' was not declared in this scope
diy_bloke 8 years ago
seems like you dont have the library installed
MaximeM 9 years ago
Hello,
I have these errors, I'm the librarie "versalino.h."
This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.
Arduino: 1.0.6 (Windows Vista), Board: "Arduino Uno"
In file included from dht11.cpp:43:
dht11.h:66: error: 'VersalinoBUS' does not name a type
dht11.h:67: error: 'VersalinoBUS' has not been declared
dht11.h:73: error: 'VersalinoBUS' has not been declared
dht11.h:76: error: 'VersalinoBUS' has not been declared
dht11.h:80: error: 'VersalinoBUS' has not been declared
dht11.h:93: error: 'VersalinoBUS' does not name a type
dht11.cpp:59: error: 'VersalinoBUS' has not been declared
dht11.cpp:66: error: 'VersalinoBUS' has not been declared
dht11.cpp: In member function 'void dht11::attach(int, int)':
dht11.cpp:69: error: '_myBUS' was not declared in this scope
dht11.cpp: At global scope:
dht11.cpp:81: error: 'VersalinoBUS' does not name a type
dht11.cpp:91: error: variable or field 'setBUS' declared void
dht11.cpp:91: error: 'VersalinoBUS' was not declared in this scope
dht11.cpp: In member function 'int dht11::read()':
dht11.cpp:111: error: '_myBUS' was not declared in this scope
dht11.cpp: At global scope:
dht11.cpp:116: error: 'VersalinoBUS' has not been declared
dht11.cpp: In member function 'int dht11::read(int, int)':
dht11.cpp:118: error: request for member 'PINS' in 'myBUS', which is of non-class type 'int'
MaximeM 9 years ago
Hello,
I forgot, I have the right DHT11 Versalino.
"Library for the Virtuabotix DHT11 Sensor"
TonatiuhS 9 years ago
Hola! Nuevo en Arduino y aprendiendo. Me interesa la meteorología y estoy haciendo tu proyecto y he encontrado algunos errores en el código, algunos ya resueltos y otros persistentes. El BMP085 arroja lecturas erróneas cuando interactúa con el DHT11 y el LCD, sin embargo funciona bien con el sketch de prueba. He intentado los siguiente: Distintas librerías, resistencias pull down, 3.3 v y 5v de alimentación, etc. ¿Alguna idea? Gracias y saludos.
rpotts2 9 years ago
parapendio.milazzo 9 years ago
the pull up resistor must be connected between data and Vcc. Actually the code is for arduino 1.0, I had to modify line 14 with :
LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
plus some others lines regarding dht 11 I had to erase "11"
Annoy Chatterjee 10 years ago
Hello, I am Annoy Chatterjee. I am making a multipurpose weather balloon for my school science fair project. I cannot understand that should the NC pin on DHT11 sensor not be connected to any wire and stay blank. Also I cannot understand that to which pin on DHT11 sensor is the 10K resistor connected to. Please help me.
c_droner 10 years ago
Hello, i am trying to download the code, but I get many errors. Hopefully you can help me. Here are the errors:
sketch_may07a:10: error: 'LiquidCrystal_I2C' does not name a type
sketch_may07a:11: error: 'dht11' does not name a type
sketch_may07a.ino: In function 'void setup()':
sketch_may07a:39: error: 'lcd' was not declared in this scope
sketch_may07a.ino: In function 'void loop()':
sketch_may07a:54: error: 'DHT11' was not declared in this scope
sketch_may07a:71: error: 'lcd' was not declared in this scope
sketch_may07a.ino: In function 'long int bmp085GetPressure(long unsigned int)':
sketch_may07a:236: error: expected primary-expression before '>' token
sketch_may07a:236: error: expected `)' before ';' token
sketch_may07a:236: error: expected `)' before ';' token
sketch_may07a.ino: In function 'long unsigned int bmp085ReadUP()':
sketch_may07a:328: error: expected primary-expression before '>' token
sketch_may07a:328: error: expected `)' before ';' token
animes25 10 years ago
you need to download the libraries, google dht11 arduino libraries,
LiquidCrystal_I2C arduino libraries, etc
bbowe1 10 years ago
what dht library did you use?