Hysha

Hello, i am using the PMOD CMPS2 compass with a Arduino Uno. I am aiming to measure the magnetic field of a current cable with this sensor. I used the example programm and rewrote it a bit so i can show the X,Y and Z component. It always shows me values of maybe 15900 and slightly changing for X Y and Z. I actually dont know if this is right. And if i hold it to a wire or something the value doesnt change. Any idea what i can do ? #define DECLINATION 2.39 // declination Germany, Duisburg /************************************************************************/ #include <Wire.h> //including library for I2C communication unsigned char CMPS2_address = 0x30; //I2C address of the device //store highest, middle and lowest values, x component and y component float Max[3], Mid[3], Min[3], X, Y, Z; void setup() { Serial.begin(9600); //serial initialization //pinMode(13, OUTPUT); delay(10); CMPS2_init(); //initialize the compass } void loop() { delay(500); //Abrufen und Anzeigen Richtung des Kompass' float measured_angle = CMPS2_getHeading(); /*Serial.print("Heading = "); Serial.print(measured_angle); Serial.print("°"); Serial.print('\t');*/ // CMPS2_decodeHeading(measured_angle); //get direction Serial.print("x="); Serial.print(X); Serial.print(" y="); Serial.print(Y); Serial.print(" z="); Serial.println(Z); } /*void CMPS2_decodeHeading(float measured_angle) { //decoding heading angle according to datasheet if (measured_angle > 337.25 | measured_angle < 22.5) { Serial.println("North"); digitalWrite(13, HIGH); } else { digitalWrite(13, LOW); if (measured_angle > 292.5) { Serial.println("North-West"); } else if (measured_angle > 247.5) { Serial.println("West"); } else if (measured_angle > 202.5) { Serial.println("South-West"); } else if (measured_angle > 157.5) { Serial.println("South"); } else if (measured_angle > 112.5) { Serial.println("South-East"); } else if (measured_angle > 67.5) { Serial.println("East"); } else { Serial.println("North-East"); } } }*/ float CMPS2_getHeading(void) { float components[3]; CMPS2_set(false); //set the polarity to normal CMPS2_read_XYZ(); //read X, Y, Z components of the magnetic field components[0] = X; //save current results components[1] = Y; components[2]= Z; CMPS2_set(true); //set the polarity to normal CMPS2_read_XYZ(); //read X, Y, Z components of the magnetic field //eliminate offset from all components components[0] = (components[0] - X) / 2.0; components[1] = (components[1] - Y) / 2.0; components[2] = (components[2] - Z) / 2.0; //variables for storing partial results float temp0 = 0; float temp1 = 0; //and for storing the final result float deg = 0; //calculate heading from components of the magnetic field //the formula is different in each quadrant if (components[0] < Mid[0]) { if (components[1] > Mid[1]) { //Quadrant 1 temp0 = components[1] - Mid[1]; temp1 = Mid[0] - components[0]; deg = 90 - atan(temp0 / temp1) * (180 / 3.14159); } else { //Quadrant 2 temp0 = Mid[1] - components[1]; temp1 = Mid[0] - components[0]; deg = 90 + atan(temp0 / temp1) * (180 / 3.14159); } } else { if (components[1] < Mid[1]) { //Quadrant 3 temp0 = Mid[1] - components[1]; temp1 = components[0] - Mid[0]; deg = 270 - atan(temp0 / temp1) * (180 / 3.14159); } else { //Quadrant 4 temp0 = components[1] - Mid[1]; temp1 = components[0] - Mid[0]; deg = 270 + atan(temp0 / temp1) * (180 / 3.14159); } } //correct heading deg += DECLINATION; if (DECLINATION > 0) { if (deg > 360) { deg -= 360; } } else { if (deg < 0) { deg += 360; } } return deg; } //reads measurements in mG void CMPS2_read_XYZ(void) { //command internal control register 0 bit 0 (measure) Wire.beginTransmission(CMPS2_address); Wire.write(0x07); Wire.write(0x01); Wire.endTransmission(); delay(8); //wait for measurement to be completed bool flag = false; while (!flag) { //jump to status register Wire.beginTransmission(CMPS2_address); Wire.write(0x06); Wire.endTransmission(); //read its value Wire.requestFrom(CMPS2_address, (uint8_t)1); int temporal = 0; if (Wire.available()) { temporal = Wire.read(); } //if the last bit is 1, data is ready temporal &= 1; if (temporal != 0) { flag = true; } } //move address pointer to first address Wire.beginTransmission(CMPS2_address); Wire.write(0x00); Wire.endTransmission(); //save data Wire.requestFrom(CMPS2_address, (uint8_t)6); byte tmp[6] = {0, 0, 0, 0, 0, 0}; //array for raw data if (Wire.available()) { for (int i = 0; i < 6; i++) { tmp[i] = Wire.read(); //save it } } //initialize array for data float measured_data[3]; //reconstruct raw data measured_data[0] = 1.0 * (int)(tmp[1] << 8 | tmp[0]); //x measured_data[1] = 1.0 * (int)(tmp[3] << 8 | tmp[2]); //y measured_data[2] = 1.0 * (int)(tmp[5] << 8 | tmp[4]); //z //convert raw data to mG for (int i = 0; i < 3; i++) { measured_data[i] = 0.48828125 * (float)measured_data[i]; } X = measured_data[0]; Y = measured_data[1]; Z = measured_data[2]; //correct minimum, mid and maximum values if (measured_data[0] > Max[0]) { //x max Max[0] = measured_data[0]; } if (measured_data[0] < Min[0]) { //x min Min[0] = measured_data[0]; } if (measured_data[1] > Max[1]) { //y max Max[1] = measured_data[1]; } if (measured_data[1] < Min[1]) { //y min Min[1] = measured_data[1]; } if (measured_data[2] > Max[2]) { //z max Max[2] = measured_data[1]; } if (measured_data[2] < Min[2]) { //z min Min[2] = measured_data[1]; } for (int i = 0; i < 3; i++) { //mid Mid[i] = (Max[i] + Min[i]) / 2; } return; } //Kompass initalisieren void CMPS2_init(void) { Wire.begin(); // I2C initialisieren //command internal control register 0 for set operation Wire.beginTransmission(CMPS2_address); Wire.write(0x07); Wire.write(0x20); Wire.endTransmission(); delay(10); //command internal control register 1 to 16 bit resolution, 8ms measurement time Wire.beginTransmission(CMPS2_address); Wire.write(0x08); Wire.write(0x00); Wire.endTransmission(); delay(10); //Minimum, Maximum und Mittelwert definieren for (int i = 0; i < 3; i++) { Max[i] = -32768; //smallest int on 16 bits Min[i] = 32767; //largest int on 16 bits Mid[i] = 0; } } //sets/resets the sensor, changing the magnetic polarity of the sensing element void CMPS2_set(bool reset) { //command internal control register 0 bit 7 (capacitor recharge) Wire.beginTransmission(CMPS2_address); Wire.write(0x07); Wire.write(0x80); Wire.endTransmission(); delay(50); if (reset) { //command internal control register 0 bit 6 (reset) Wire.beginTransmission(CMPS2_address); Wire.write(0x07); Wire.write(0x40); Wire.endTransmission(); delay(10); } else { //command internal control register 0 bit 5 (set) Wire.beginTransmission(CMPS2_address); Wire.write(0x07); Wire.write(0x20); Wire.endTransmission(); delay(10); } return; }