Declination sensor transmitter #include #include #include #include #include // UUIDs created using https://www.uuidgenerator.net/ #define IMU_SERVICE_UUID "468c28f3-35a2-4fe8-9e68-be7942c4f152" #define IMU_TEMP_UUID "66fbf839-f54e-4162-91a7-8c41464d4b0e" #define IMU_XYZ_UUID "bd38d6a4-d815-4e50-a9c0-7b9420043151" #define IMU_SOUTH_UUID "c8ed185c-25d9-4507-a6ad-7aeefcf6cc5e" // CurieNano acts as a BLE peripheral BLEPeripheral blePeripheral; // IMU data is registered as a BLE service BLEService imuService(IMU_SERVICE_UUID); // Each IMU data point is its own characteristic BLECharacteristic imuXYZ(IMU_XYZ_UUID, BLERead | BLENotify,16); BLECharacteristic imuTemp(IMU_TEMP_UUID, BLERead, 16); BLECharacteristic imuSouth(IMU_SOUTH_UUID, BLERead, 16); // Assign pin to indicate BLE connection const int INDICATOR_PIN = 13; DFRobot_QMC5883 compass; unsigned long microsPerReading, microsPrevious; float accelScale; int ax, ay, az, axsum, aysum, azsum; float mx, my, mxsum, mysum; float temperature, southheading; void setup(){ Serial.begin(9600); // Initialize BLE peripheral blePeripheral.setLocalName("IMUA"); blePeripheral.setAdvertisedServiceUuid(imuService.uuid()); blePeripheral.addAttribute(imuService); blePeripheral.addAttribute(imuXYZ); blePeripheral.addAttribute(imuTemp); blePeripheral.addAttribute(imuSouth); // Now, activate the BLE peripheral blePeripheral.begin(); Serial.println("Bluetooth device active, waiting for connections..."); // Initialize HMC5883L Serial.println("Initialize HMC5883L"); while (!compass.begin()){ Serial.println("Could not find a valid HMC5883L sensor, check wiring!"); delay(500); } // Set measurement range compass.setRange(HMC5883L_RANGE_1_3GA); // Set measurement mode compass.setMeasurementMode(HMC5883L_CONTINOUS); // Set data rate compass.setDataRate(HMC5883L_DATARATE_30HZ); // Set number of samples averaged compass.setSamples(HMC5883L_SAMPLES_8); // start the IMU CurieIMU.begin(); CurieIMU.setAccelerometerRate(25); // Set the accelerometer range to 1G CurieIMU.setAccelerometerRange(1); // initialize variables to pace updates to correct rate microsPerReading = 1000000 / 25; microsPrevious = micros(); } void loop() { int n=10; int j=0; String south = ""; String southsign = ""; String southdata = ""; char southbuf[10] = ""; String temp = ""; String tempdata = ""; char tempbuf[10] = ""; // Check if the connection to the central is active or not BLECentral central = blePeripheral.central(); if(central) { Serial.print("Connected to central: "); Serial.println(central.address()); digitalWrite(INDICATOR_PIN, HIGH); // Take average of acquired data mxsum = 0, mysum = 0, axsum = 0, aysum = 0, azsum = 0; for(j=0; j= microsPerReading) { // read raw data from CurieIMU CurieIMU.readAccelerometer(aix, aiy, aiz); ax = aiy; ay = aiz; az = aix; // Read magnetometer Vector norm = compass.readNormalize(); mx = norm.XAxis; my = -norm.YAxis; // Read and calculate IMU sensor temperature temperature = CurieIMU.readTemperature(); temperature = temperature/512 + 23; // increment previous time to maintain pace microsPrevious = microsPrevious + microsPerReading; } } // Transmit up to three signed four digit Hex numbers void SendData(){ char messagebuf[21] = ""; String message = ""; String signx = "", signy = "", signz = ""; String xdata = String(1*abs(axsum),HEX); String ydata = String(int(1*abs(aysum)),HEX); String zdata = String(int(1*abs(azsum)), HEX); if (axsum<0){ signx = "-"; } else { signx = "+"; } if (aysum<0){ signy = "-"; } else { signy = "+"; } if (azsum<0){ signz = "-"; } else { signz = "+"; } message = signx+xdata+signy+ydata+signz+zdata+"-"; message.toCharArray(messagebuf, 21); imuXYZ.setValue((unsigned char*)messagebuf,21); Serial.print(messagebuf); Serial.print("\n"); }