Matthias Grob / Mbed 2 deprecated IMU_10DOF

An fully working IMU-Filter and Sensor drivers for the 10DOF-Board over I2C. All in one simple class. Include, calibrate sensors, call read, get angles. (3D Visualisation code for Python also included) Sensors: L3G4200D, ADXL345, HMC5883, BMP085

Dependencies:   mbed

IMU/Sensors/Acc/ADXL345.cpp@4:f62337b907e5, 2013-08-29 (annotated)

Committer:
maetugr
Date:
Thu Aug 29 13:52:30 2013 +0000
Revision:
4:f62337b907e5
Parent:
0:3e7450f1a938 
The Altitude Sensor is now implemented, it's really 10DOF now ;); TODO: Autocalibration

Who changed what in which revision?

UserRevisionLine numberNew contents of line
maetugr 0:3e7450f1a938 1 #include "ADXL345.h"
maetugr 0:3e7450f1a938 2
maetugr 0:3e7450f1a938 3 ADXL345::ADXL345(PinName sda, PinName scl) : I2C_Sensor(sda, scl, ADXL345_I2C_ADDRESS)
maetugr 0:3e7450f1a938 4 {
maetugr 4:f62337b907e5 5 #warning these three offsets are calibration values to make shure the measurement is 0 when no acceleration is present
maetugr 0:3e7450f1a938 6 offset[0] = -9.1; // offset calculated by hand... (min + ((max - min) / 2)
maetugr 0:3e7450f1a938 7 offset[1] = -7.1; // TODO: make this automatic with saving to filesystem
maetugr 0:3e7450f1a938 8 offset[2] = 6;
maetugr 0:3e7450f1a938 9
maetugr 0:3e7450f1a938 10 // Set Offset - programmed into the OFSX, OFSY, and OFXZ registers, respectively, as 0xFD, 0x03 and 0xFE.
maetugr 0:3e7450f1a938 11 writeRegister(ADXL345_OFSX_REG, 0xFA); // to get these offsets just lie your sensor down on the table always the axis pointing down to earth has 200+ and the others should have more or less 0
maetugr 0:3e7450f1a938 12 writeRegister(ADXL345_OFSY_REG, 0xFE);
maetugr 0:3e7450f1a938 13 writeRegister(ADXL345_OFSZ_REG, 0x0A);
maetugr 0:3e7450f1a938 14
maetugr 0:3e7450f1a938 15 writeRegister(ADXL345_BW_RATE_REG, 0x0F); // 3200Hz BW-Rate
maetugr 0:3e7450f1a938 16 writeRegister(ADXL345_DATA_FORMAT_REG, 0x0B); // set data format to full resolution and +-16g
maetugr 0:3e7450f1a938 17 writeRegister(ADXL345_POWER_CTL_REG, 0x08); // set mode
maetugr 0:3e7450f1a938 18 }
maetugr 0:3e7450f1a938 19
maetugr 0:3e7450f1a938 20 void ADXL345::read(){
maetugr 0:3e7450f1a938 21 readraw();
maetugr 0:3e7450f1a938 22 for (int i = 0; i < 3; i++)
maetugr 0:3e7450f1a938 23 data[i] = raw[i] - offset[i]; // TODO: didnt care about units
maetugr 0:3e7450f1a938 24 }
maetugr 0:3e7450f1a938 25
maetugr 0:3e7450f1a938 26 void ADXL345::readraw(){
maetugr 0:3e7450f1a938 27 char buffer[6];
maetugr 0:3e7450f1a938 28 readMultiRegister(ADXL345_DATAX0_REG, buffer, 6);
maetugr 0:3e7450f1a938 29
maetugr 0:3e7450f1a938 30 raw[0] = (short) ((int)buffer[1] << 8 | (int)buffer[0]);
maetugr 0:3e7450f1a938 31 raw[1] = (short) ((int)buffer[3] << 8 | (int)buffer[2]);
maetugr 0:3e7450f1a938 32 raw[2] = (short) ((int)buffer[5] << 8 | (int)buffer[4]);
maetugr 0:3e7450f1a938 33 }
maetugr 0:3e7450f1a938 34
maetugr 0:3e7450f1a938 35 void ADXL345::calibrate(int times, float separation_time)
maetugr 0:3e7450f1a938 36 {
maetugr 0:3e7450f1a938 37 // calibrate sensor with an average of count samples (result of calibration stored in offset[])
maetugr 0:3e7450f1a938 38 float calib[3] = {0,0,0}; // temporary array for the sum of calibration measurement
maetugr 0:3e7450f1a938 39
maetugr 0:3e7450f1a938 40 for (int j = 0; j < times; j++) { // read 'times' times the data in a very short time
maetugr 0:3e7450f1a938 41 readraw();
maetugr 0:3e7450f1a938 42 for (int i = 0; i < 3; i++)
maetugr 0:3e7450f1a938 43 calib[i] += raw[i];
maetugr 0:3e7450f1a938 44 wait(separation_time);
maetugr 0:3e7450f1a938 45 }
maetugr 0:3e7450f1a938 46
maetugr 0:3e7450f1a938 47 for (int i = 0; i < 3; i++)
maetugr 0:3e7450f1a938 48 offset[i] = calib[i]/times; // take the average of the calibration measurements
maetugr 0:3e7450f1a938 49 }