skule.sormo.no

{jcomments on}I Oppsettet brukes en Arduino UNO med GY-87 (10DOF (degree Of Freedom) 3-axis Gyro + 3-axis Acceleration + 3-axis Magnetic Field + Air Pressure Module)  der trykk/temperaturdelen (BMP180) er brukt. En annen IMU eller modul kan også brukes som måler temperatur og trykk, men den må ha BMP180-enheten koblet til en i2-linje med SDA og SCL - tilkobling for at programmet under skal fungere.  EM411 GPS er brukt her med en baudrate på 4800 bps.

Her kan du laste ned fila med bibliotekfunksjoner

/*************************************************************** * * CanSat versjon med Arduino UNO. * Biblitoekene AltSoftSerial brukes til GPS med baudrate 4800, pinne 9 mottar signalet. * GY-87 er en 10 IMU med MPU6050(asc/gyro), HMC5883L(magm) og BMP180 (trykk/temp) * der biblioteket SFE_BMP180 brukes til å lese trykk og temperatur. * Eksempelprogram fra SFE_BMP180 er brukt og modifisert slik at også GPS leses via * AltSoftSerial-porten. Koden er i stor grad bevart, men merket som kommentar. * Time-code er lagt til i starten på hver dataline, også på GPS. * De øvrige data har en label (timecode,temp,abs pres,rel(sea)pres,alt:) før dataverdien * skrives skilt med komma. Da blir det lettere å importere dette i regneark for plott. * (C) Skule Sørmo 24.02.2015 * ***********************************************************************************/ #include <AltSoftSerial.h> #include <SFE_BMP180.h> #include <Wire.h> /* SFE_BMP180 library example sketch This sketch shows how to use the SFE_BMP180 library to read the Bosch BMP180 barometric pressure sensor. https://www.sparkfun.com/products/11824 Like most pressure sensors, the BMP180 measures absolute pressure. This is the actual ambient pressure seen by the device, which will vary with both altitude and weather. Before taking a pressure reading you must take a temparture reading. This is done with startTemperature() and getTemperature(). The result is in degrees C. Once you have a temperature reading, you can take a pressure reading. This is done with startPressure() and getPressure(). The result is in millibar (mb) aka hectopascals (hPa). If you'll be monitoring weather patterns, you will probably want to remove the effects of altitude. This will produce readings that can be compared to the published pressure readings from other locations. To do this, use the sealevel() function. You will need to provide the known altitude at which the pressure was measured. If you want to measure altitude, you will need to know the pressure at a baseline altitude. This can be average sealevel pressure, or a previous pressure reading at your altitude, in which case subsequent altitude readings will be + or - the initial baseline. This is done with the altitude() function. Hardware connections: - (GND) to GND + (VDD) to 3.3V (WARNING: do not connect + to 5V or the sensor will be damaged!) You will also need to connect the I2C pins (SCL and SDA) to your Arduino. The pins are different on different Arduinos: Any Arduino pins labeled: SDA SCL Uno, Redboard, Pro: A4 A5 Mega2560, Due: 20 21 Leonardo: 2 3 Leave the IO (VDDIO) pin unconnected. This pin is for connecting the BMP180 to systems with lower logic levels such as 1.8V Have fun! -Your friends at SparkFun. The SFE_BMP180 library uses floating-point equations developed by the Weather Station Data Logger project: http://wmrx00.sourceforge.net/ Our example code uses the "beerware" license. You can do anything you like with this code. No really, anything. If you find it useful, buy me a beer someday. V10 Mike Grusin, SparkFun Electronics 10/24/2013 */ // Your sketch must #include this library, and the Wire library. // (Wire is a standard library included with Arduino.): // You will need to create an SFE_BMP180 object, here called "pressure": SFE_BMP180 pressure; AltSoftSerial GPS_port; #define ALTITUDE 1655.0 // Altitude of SparkFun's HQ in Boulder, CO. in meters String buffer=""; const int chipSelect = 4; void setup() { Serial.begin(9600); GPS_port.begin(4800); Serial.println("REBOOT"); buffer.reserve(127); // Initialize the sensor (it is important to get calibration values stored on the device). if (pressure.begin()) Serial.println("BMP180 init success"); else { // Oops, something went wrong, this is usually a connection problem, // see the comments at the top of this sketch for the proper connections. Serial.println("BMP180 init fail\n\n"); while(1); // Pause forever. } } void loop() { char status; double T,P,p0,a; while (GPS_port.available()) { char c=GPS_port.read(); if (int(c)==13) { Serial.print(__TIME__); Serial.print(","); Serial.println(buffer); buffer=""; } else if (int(c)!=10) buffer +=c; } // Loop here getting pressure readings every 10 seconds. // If you want sea-level-compensated pressure, as used in weather reports, // you will need to know the altitude at which your measurements are taken. // We're using a constant called ALTITUDE in this sketch: /* Serial.println(); Serial.print("provided altitude: "); Serial.print(ALTITUDE,0); Serial.print(" meters, "); Serial.print(ALTITUDE*3.28084,0); Serial.println(" feet"); */ // If you want to measure altitude, and not pressure, you will instead need // to provide a known baseline pressure. This is shown at the end of the sketch. // You must first get a temperature measurement to perform a pressure reading. // Start a temperature measurement: // If request is successful, the number of ms to wait is returned. // If request is unsuccessful, 0 is returned. status = pressure.startTemperature(); if (status != 0) { // Wait for the measurement to complete: delay(status); // Retrieve the completed temperature measurement: // Note that the measurement is stored in the variable T. // Function returns 1 if successful, 0 if failure. status = pressure.getTemperature(T); if (status != 0) { // Print out the measurement: Serial.print("timecode,temp,abs pres,rel(sea)pres,alt: "); Serial.print(__TIME__); Serial.print(","); Serial.print(T,2); Serial.print(","); // Serial.print(" deg C, "); // Serial.print((9.0/5.0)*T+32.0,2); // Serial.println(" deg F"); // Start a pressure measurement: // The parameter is the oversampling setting, from 0 to 3 (highest res, longest wait). // If request is successful, the number of ms to wait is returned. // If request is unsuccessful, 0 is returned. status = pressure.startPressure(3); if (status != 0) { // Wait for the measurement to complete: delay(status); // Retrieve the completed pressure measurement: // Note that the measurement is stored in the variable P. // Note also that the function requires the previous temperature measurement (T). // (If temperature is stable, you can do one temperature measurement for a number of pressure measurements.) // Function returns 1 if successful, 0 if failure. status = pressure.getPressure(P,T); if (status != 0) { // Print out the measurement: // Serial.print("absolute pressure: "); Serial.print(P,2); Serial.print(","); // Serial.print(" mb, "); // Serial.print(P*0.0295333727,2); // Serial.println(" inHg"); // The pressure sensor returns abolute pressure, which varies with altitude. // To remove the effects of altitude, use the sealevel function and your current altitude. // This number is commonly used in weather reports. // Parameters: P = absolute pressure in mb, ALTITUDE = current altitude in m. // Result: p0 = sea-level compensated pressure in mb p0 = pressure.sealevel(P,ALTITUDE); // we're at 1655 meters (Boulder, CO) // Serial.print("relative (sea-level) pressure: "); Serial.print(p0,2); Serial.print(","); // Serial.print(" mb, "); // Serial.print(p0*0.0295333727,2); // Serial.println(" inHg"); // On the other hand, if you want to determine your altitude from the pressure reading, // use the altitude function along with a baseline pressure (sea-level or other). // Parameters: P = absolute pressure in mb, p0 = baseline pressure in mb. // Result: a = altitude in m. a = pressure.altitude(P,p0); // Serial.print("computed altitude: "); Serial.println(a,0); // Serial.print(","); // Serial.print(" meters, "); // Serial.print(a*3.28084,0); // Serial.println(" feet"); } else Serial.println("error retrieving pressure measurement\n"); } else Serial.println("error starting pressure measurement\n"); } else Serial.println("error retrieving temperature measurement\n"); } else Serial.println("error starting temperature measurement\n"); //delay(100); // Pause for 5 seconds. }