Oke, just after i posted the previous results i managed to fix the problem. I made an error in the constant ADXL345_MG2G_MULTIPLIER, i forgot an extra zero. Further both bytes should be converted to (int) however the first should be corrected if the byte is negative. For this i used asInt(byte b). The whole code is written below:
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package sensor;
import java.io.IOException;
import java.nio.ByteBuffer;
import com.pi4j.io.i2c.I2CBus;
import com.pi4j.io.i2c.I2CDevice;
public class Accel {
/**
* Trying to implement the I2C connection
* implemented on ADXL345 Adafruit code
*/
private I2CDevice device;
/*
* Adress uit Arduino code
*
*
*/
/*
* REGISTERS
-----------------------------------------------------------------------
#define ADXL345_REG_DEVID (0x00) // Device ID
#define ADXL345_REG_THRESH_TAP (0x1D) // Tap threshold
#define ADXL345_REG_OFSX (0x1E) // X-axis offset
#define ADXL345_REG_OFSY (0x1F) // Y-axis offset
#define ADXL345_REG_OFSZ (0x20) // Z-axis offset
#define ADXL345_REG_DUR (0x21) // Tap duration
#define ADXL345_REG_LATENT (0x22) // Tap latency
#define ADXL345_REG_WINDOW (0x23) // Tap window
#define ADXL345_REG_THRESH_ACT (0x24) // Activity threshold
#define ADXL345_REG_THRESH_INACT (0x25) // Inactivity threshold
#define ADXL345_REG_TIME_INACT (0x26) // Inactivity time
#define ADXL345_REG_ACT_INACT_CTL (0x27) // Axis enable control for activity and inactivity detection
#define ADXL345_REG_THRESH_FF (0x28) // Free-fall threshold
#define ADXL345_REG_TIME_FF (0x29) // Free-fall time
#define ADXL345_REG_TAP_AXES (0x2A) // Axis control for single/double tap
#define ADXL345_REG_ACT_TAP_STATUS (0x2B) // Source for single/double tap
#define ADXL345_REG_BW_RATE (0x2C) // Data rate and power mode control
#define ADXL345_REG_POWER_CTL (0x2D) // Power-saving features control
#define ADXL345_REG_INT_ENABLE (0x2E) // Interrupt enable control
#define ADXL345_REG_INT_MAP (0x2F) // Interrupt mapping control
#define ADXL345_REG_INT_SOURCE (0x30) // Source of interrupts
#define ADXL345_REG_DATA_FORMAT (0x31) // Data format control
#define ADXL345_REG_DATAX0 (0x32) // X-axis data 0
#define ADXL345_REG_DATAX1 (0x33) // X-axis data 1
#define ADXL345_REG_DATAY0 (0x34) // Y-axis data 0
#define ADXL345_REG_DATAY1 (0x35) // Y-axis data 1
#define ADXL345_REG_DATAZ0 (0x36) // Z-axis data 0
#define ADXL345_REG_DATAZ1 (0x37) // Z-axis data 1
#define ADXL345_REG_FIFO_CTL (0x38) // FIFO control
#define ADXL345_REG_FIFO_STATUS (0x39) // FIFO status
*/
private static final byte ADRESS = 0x53;
private static final byte ADXL345_REG_POWER_CTL = 0x2D;
private static final byte ADXL345_REG_DATAX0 = 0x32; //X-axis data 0
private static final byte ADXL345_REG_DATAY0 = 0x34; //Y-axis data 0
private static final byte ADXL345_REG_DATAZ0 = 0x36; //Z-axis data 0
private static final double ADXL345_MG2G_MULTIPLIER = 0.004; // 4mg per lsb
private static final float SENSOR_GRAVITY_STANDARD = 9.80665F;
private static final int ADXL345_REG_OFSY = 0x1F;
public Accel(I2CBus bus) throws IOException{
System.out.println("Starting Accel");
device = bus.getDevice(ADRESS);
device.write(ADXL345_REG_POWER_CTL, (byte)0x08);
}
public void readAxis() throws IOException{
//device.write(ADXL345_REG_DATAY0); //send data to register to read
byte[] buff = new byte[2];
device.read(ADXL345_REG_DATAY0,buff,0,2);
int response = (asInt(buff[0]) | ((int)buff[1])<< 8);
double y = (double)response * ADXL345_MG2G_MULTIPLIER * SENSOR_GRAVITY_STANDARD;
System.out.println(y);
}
public int asInt(byte b){
int i = b;
if(i<0){
i = i +256;
}
return i;
}
}
I used the GY-80 as sensor, which i know a lot of people use for their home projects. Is there a place where i can submit my code so others can use it as well?
Thank you for the response!
