I am able to get angle from ADXL345 and L3GD20. Please use this program. Angle is made by deg/sec and acceramater. I used Kalmanfilter.

Fork of ANGLE by Kiko Ishimoto

Revision:
0:15e41c824e3b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/angle.cpp	Sun Nov 30 11:06:13 2014 +0000
@@ -0,0 +1,492 @@
+#include "angle.h"
+#include "mbed.h"
+ANGLE::ANGLE(PinName sda, PinName scl) : i2c_(sda, scl) {
+    Rate=0.00390635;sampleTime=0.001;sampleNum=500;
+
+    kalma[0].setAngle(0);
+    kalma[1].setAngle(0);
+    kalma[2].setAngle(0);
+    //400kHz, allowing us to use the fastest data rates.
+    i2c_.frequency(400000);
+    // initialize the BW data rate
+    char tx[2];
+    tx[0] = ADXL345_BW_RATE_REG;
+    tx[1] = ADXL345_200HZ; //value greater than or equal to 0x0A is written into the rate bits (Bit D3 through Bit D0) in the BW_RATE register 
+    i2c_.write( acc_i2c_write , tx, 2);  
+    
+    //Data format (for +-16g) - This is done by setting Bit D3 of the DATA_FORMAT register (Address 0x31) and writing a value of 0x03 to the range bits (Bit D1 and Bit D0) of the DATA_FORMAT register (Address 0x31).
+    
+    char rx[2];
+    rx[0] = ADXL345_DATA_FORMAT_REG;
+    rx[1] = 0x0B; 
+     // full res and +_16g
+    i2c_.write( acc_i2c_write , rx, 2); 
+    
+    // Set Offset  - programmed into the OFSX, OFSY, and OFXZ registers, respectively, as 0xFD, 0x03 and 0xFE.
+    char x[2];
+    x[0] = ADXL345_OFSX_REG ;
+    x[1] = 253; 
+    i2c_.write( acc_i2c_write , x, 2);
+    char y[2];
+    y[0] = ADXL345_OFSY_REG ;
+    y[1] = 5; 
+    i2c_.write( acc_i2c_write, y, 2);
+    char z[2];
+    z[0] = ADXL345_OFSZ_REG ;
+    z[1] = 0xFE; 
+    i2c_.write( acc_i2c_write , z, 2);
+     char reg_v;
+    sampleTime=0.001;
+    sampleNum=500;
+    angle[0]=angle[1]=angle[2]=0;
+    prev_rate[0]=prev_rate[1]=prev_rate[2]=0;
+    
+    // 0x0F = 0b00001111
+    // Normal power mode, all axes enabled
+    reg_v = 0;
+    reg_v |= 0x0F;
+    write_reg(GYR_ADDRESS,L3GD20_CTRL_REG1,reg_v);
+    set_offset();
+    set_noise();
+    
+    offset_angle[0]=0;
+    offset_angle[1]=0;
+    offset_angle[2]=0;
+    ADXL_setup();
+    set_angleoffset();
+    }
+void ANGLE::ADXL_setup(){
+      z_offset=2;x_offset=0;y_offset=0;
+      char buffer[6];    
+
+          for(int i=0;i<sampleNum;i++)
+  {
+        data_multi_get(ADXL345_DATAX0_REG, buffer, 6);
+        int Xacc = (int)buffer[1] << 8 | (int)buffer[0];
+        int Yacc = (int)buffer[3] << 8 | (int)buffer[2];
+        int Zacc = (int)buffer[5] << 8 | (int)buffer[4]-255;
+    if((int)Xacc-x_offset>xnoise)
+      xnoise=(int)Xacc-x_offset;
+    else if((int)Xacc-x_offset<-xnoise)
+      xnoise=-(int)Xacc-x_offset;
+
+    if((int)Yacc-y_offset>ynoise)
+      ynoise=(int)Yacc-y_offset;
+    else if((int)Yacc-y_offset<-ynoise)
+      ynoise=-(int)Yacc-y_offset; 
+
+    if((int)Zacc-z_offset>znoise)
+      znoise=(int)Zacc-z_offset;
+    else if((int)Zacc-z_offset<-znoise)
+      znoise=-(int)Zacc-z_offset; 
+  }
+        
+      
+}
+void ANGLE::ADXL_setnum(int Num,float time,double rate){
+        sampleNum=Num;sampleTime=time;Rate=rate;
+}
+char ANGLE::data_single_get(char reg){   
+   char tx = reg;
+   char output; 
+    i2c_.write( acc_i2c_write , &tx, 1);  //tell it what you want to read
+    i2c_.read( acc_i2c_read , &output, 1);    //tell it where to store the data
+    return output;
+}
+int ANGLE::data_single_put(char reg, char data){ 
+   int ack = 0;
+   char tx[2];
+   tx[0] = reg;
+   tx[1] = data;
+   return   ack | i2c_.write( acc_i2c_write , tx, 2);   
+}
+
+
+
+void ANGLE::data_multi_get(char reg, char* data, int size) {
+    i2c_.write( acc_i2c_write, &reg, 1);  //tell it where to read from
+    i2c_.read( acc_i2c_read , data, size);      //tell it where to store the data read
+}
+
+
+int ANGLE::data_multi_put(char reg, char* data, int size) {
+        int ack;
+   
+               ack = i2c_.write( acc_i2c_write, &reg, 1);  //tell it where to write to
+        return ack | i2c_.write( acc_i2c_read, data, size);  //tell it what data to write                                   
+}
+void ANGLE::getangle_acc(double* DATA_ANGLE){
+    char buffer[6];
+    short data[3];    
+    //data_multi_get(ADXL345_DATAX0_REG, buffer, 6);
+    getaxis_acc(data);
+      // calculate the absolute of the magnetic field vector                                    // 8-Bit pieces of axis data
+      // read axis registers using I2C
+    
+    /*data[0] = (short) (buffer[1] << 8 | buffer[0]);//-x_offset;     // join 8-Bit pieces to 16-bit short integers
+    data[1] = (short) (buffer[3] << 8 | buffer[2]);//-y_offset;
+    data[2] = (short) (buffer[5] << 8 | buffer[4]);//-z_offset;*/
+    float R = sqrt(pow((float)data[0],2) + pow((float)data[1],2) + pow((float)data[2],2));
+    DATA_ANGLE[1] =   -((180 / 3.1415) * acos((float)data[1] / R)-90);                                    // roll - angle of magnetic field vector in x direction
+    DATA_ANGLE[0] =   (180 / 3.1415) * acos((float)data[0] / R)-90;                                    // pitch - angle of magnetic field vector in y direction
+    DATA_ANGLE[2] =   (180 / 3.1415) * acos((float)data[2] / R); //*/
+    DATA_ANGLE[0] = atan2(data[0],sqrt(pow((float)data[1],2)+pow((float)data[2],2)))*180/3.1415;
+    DATA_ANGLE[1] = atan2(data[1],sqrt(pow((float)data[0],2)+pow((float)data[2],2)))*180/3.1415;
+    DATA_ANGLE[2] = atan2(sqrt(pow((float)data[1],2)+pow((float)data[2],2)),data[2])*180/3.1415;
+   /*DATA_ANGLE[0]=atan2((double)data[0],(double)data[2])* (180 / 3.1415);
+    DATA_ANGLE[1]=atan2((double)data[1],(double)data[2])* (180 / 3.1415);
+   /* if(data[0]>255)
+      DATA_ANGLE[0]=-90;
+    else if(data[0]<-263)
+      DATA_ANGLE[0]=90;
+    if(data[1]>260)
+      DATA_ANGLE[1]=90;
+    else if(data[1]<-246)
+      DATA_ANGLE[1]=-90;
+    /*if(DATA[1]>250)
+      DATA_ANGLE[1]=90;
+    else if(DATA[1]<-260)
+      DATA_ANGLE[1]=-90;
+    if(DATA[0]>250)
+      DATA_ANGLE[0]=90;
+    else if(DATA[0]<-260)
+      DATA_ANGLE[0]=-90;*/
+      }
+void ANGLE::getaxis_acc(short* DATA_ACC){
+    char buffer[6];
+    data_multi_get(ADXL345_DATAX0_REG, buffer, 6);
+    
+    DATA_ACC[0] = ((short)buffer[1] << 8 | (short)buffer[0]);//+0.1*tempDATA_ACC[0];//-x_offset;
+    DATA_ACC[1] = ((short)buffer[3] << 8 | (short)buffer[2]);//+0.1*tempDATA_ACC[1];//-y_offset;
+    DATA_ACC[2] = ((short)buffer[5] << 8 | (short)buffer[4]);//+0.1*tempDATA_ACC[2];//-z_offset;
+    DATA_ACC[0] = (short)(DATA_ACC[0]*0.9+tempDATA_ACC[0]*0.1);
+    DATA_ACC[1] = (short)(DATA_ACC[1]*0.9+tempDATA_ACC[0]*0.1);
+    DATA_ACC[2] = (short)(DATA_ACC[2]*0.9+tempDATA_ACC[0]*0.1);
+    tempDATA_ACC[0]=DATA_ACC[0];
+    tempDATA_ACC[1]=DATA_ACC[1];
+    tempDATA_ACC[2]=DATA_ACC[2];//*/
+}
+void ANGLE::get_rate(short* RATE)
+{
+    short axis[3];
+    short offset_t[3]={-1,+1,0};
+    read(axis);
+    for(int i=0; i<3; i++){
+        RATE[i]=(short)(axis[i])*0.01-offset_t[i];
+        //RATE[i]=(floor(RATE[i]));
+        }
+}
+void ANGLE::get_angle(double *x,double *y,double *z)
+{
+    *x=(floor(angle[0]*100.0)/100.0);
+    *y=(floor(angle[1]*100.0)/100.0);
+    *z=(floor(angle[2]*100.0)/100.0);
+}
+void ANGLE::get_angle_rate(double *x,double *y,double *z)
+{
+    
+    *x=t[0];
+    *y=t[1];
+    *z=t[2];
+}
+
+void ANGLE::get_Synthesis_angle(double* X,double* Y)
+{
+        *X=Synthesis_angle[0];
+        *Y=Synthesis_angle[1];
+}
+void ANGLE::get_Comp_angle(double* X,double* Y)
+{
+        *X=comp_angle[0];
+        *Y=comp_angle[1];
+}
+void ANGLE::get_Kalman_angle(double* X,double* Y)
+{
+        *X=kalman_angle[0];
+        *Y=kalman_angle[1];
+}
+void ANGLE::set_angle(double ANG_x,double ANG_y,double ANG_z)
+{
+    Synthesis_angle[0]=angle[0]=ANG_x;
+    Synthesis_angle[1]=angle[1]=ANG_y;
+    angle[2]=ANG_z;
+}
+void ANGLE::set_angle()
+{
+    get_rate(rate);
+    double g[3], d[3];
+    get_angle(g,g+1,g+2);
+    getangle_acc(d);
+    double S[3];
+    for(int i=0; i<3; i++) {
+        //rate[i]=rate[i]*0.00875;
+        
+        S[i]  =((double)(rate[i]+prev_rate[i])*sampleTime/2);
+        // S[i]=(floor(S[i]*100.0)/100.0);//-offset_angle[i];
+        //angle[i]+=(floor(t[i]*100.0)/100.0);//-offset_angle[i];
+        angle[i]+=(double)S[i];
+        Synthesis_angle[i]+=(double)S[i];
+        Synthesis_angle[i]=0.99*(double)(Synthesis_angle[i]+(double)rate[i]/1020.5)+0.01*d[i];
+        kalman_angle[i]=kalma[i].getAngle((double)d[i], (double)rate[i], (double)sampleTime*1000);
+        comp_angle[i]=kalman_angle[i]*0.01+Synthesis_angle[i]*0.01+comp_angle[i]*0.98;
+        prev_rate[i]=rate[i];
+    }
+}
+void ANGLE::set_angleoffset()
+{
+     double axis[3],offseta[3];
+     offseta[0]=offseta[1]=offseta[2]=0;
+    offset_angle[0]=0;
+    offset_angle[1]=0;
+    offset_angle[2]=0;
+    for(int i=0; i<sampleNum; i++) {
+        set_angle();
+        get_angle_rate(axis,axis+1,axis+2);
+        offseta[0]+=axis[0];
+        offseta[1]+=axis[1];
+        offseta[2]+=axis[2];
+    }
+    offset_angle[0]=offseta[0]/sampleNum;
+    offset_angle[1]=offseta[1]/sampleNum;
+    offset_angle[2]=offseta[2]/sampleNum;
+    offset_angle[0]=(floor(offset_angle[0]*100.0)/100.0);
+    offset_angle[1]=(floor(offset_angle[1]*100.0)/100.0);
+    offset_angle[2]=(floor(offset_angle[2]*100.0)/100.0);
+    angle[0]=0;
+    angle[1]=0;
+    angle[2]=0;
+}
+void ANGLE::set_noise()
+{
+    short gyal[3];
+    noise[0]=noise[1]=noise[2]=0;
+
+    for(int i=0; i<sampleNum; i++) {
+
+        for(int t=0; t<3; t++) {
+            read(gyal);
+            if((int)gyal[t]>noise[t])
+                noise[t]=(int)gyal[t];
+            else if((int)gyal[t]<-noise[t])
+                noise[t]=-(int)gyal[t];
+        }
+    }
+    noise[0]*=sampleTime;
+    noise[1]*=sampleTime;
+    noise[2]*=sampleTime;
+}
+void ANGLE::set_offset()
+{
+    short axis[3],offseta[3];
+    offseta[0]=0;
+    offseta[1]=0;
+    offseta[2]=0;
+    for(int i=0; i<sampleNum; i++) {
+        read(axis);
+        offseta[0]+=axis[0];
+        offseta[1]+=axis[1];
+        offseta[2]+=axis[2];
+    }
+    offset[0]=offseta[0]/sampleNum;
+    offset[1]=offseta[1]/sampleNum;
+    offset[2]=offseta[2]/sampleNum;
+}
+bool ANGLE::read(short *axis)
+{
+    char gyr[6];
+
+    if (recv(GYR_ADDRESS, L3GD20_OUT_X_L, gyr, 6)) {
+        //scale is 8.75 mdps/digit
+        axis[0] =  (short(gyr[1] << 8 | gyr[0]))-offset[0];
+        axis[1] =  (short(gyr[3] << 8 | gyr[2]))-offset[1];
+        axis[2] =  (short(gyr[5] << 8 | gyr[4]))-offset[2];
+
+
+        return true;
+    }
+
+    return false;
+}
+bool ANGLE::read(float *gx, float *gy, float *gz)
+{
+    char gyr[6];
+
+    if (recv(GYR_ADDRESS, L3GD20_OUT_X_L, gyr, 6)) {
+        //scale is 8.75 mdps/digit
+        *gx =  float(short(gyr[1] << 8 | gyr[0])-offset[0])*0.00875*sampleTime;
+        *gy =  float(short(gyr[3] << 8 | gyr[2])-offset[1])*0.00875*sampleTime;
+        *gz =  float(short(gyr[5] << 8 | gyr[4])-offset[2])*0.00875*sampleTime;
+
+
+        return true;
+    }
+
+    return false;
+}
+
+
+
+
+bool ANGLE::write_reg(int addr_i2c,int addr_reg, char v)
+{
+    char data[2] = {addr_reg, v};
+    return ANGLE::i2c_.write(addr_i2c, data, 2) == 0;
+}
+
+bool ANGLE::read_reg(int addr_i2c,int addr_reg, char *v)
+{
+    char data = addr_reg;
+    bool result = false;
+
+    __disable_irq();
+    if ((i2c_.write(addr_i2c, &data, 1) == 0) && (i2c_.read(addr_i2c, &data, 1) == 0)) {
+        *v = data;
+        result = true;
+    }
+    __enable_irq();
+    return result;
+}
+
+
+bool ANGLE::recv(char sad, char sub, char *buf, int length)
+{
+    if (length > 1) sub |= 0x80;
+
+    return i2c_.write(sad, &sub, 1, true) == 0 && i2c_.read(sad, buf, length) == 0;
+}
+int ANGLE::setPowerMode(char mode) { 
+
+    //Get the current register contents, so we don't clobber the rate value.
+    char registerContents = (mode << 4) | data_single_get(ADXL345_BW_RATE_REG);
+
+   return data_single_put(ADXL345_BW_RATE_REG, registerContents);
+
+}
+int ANGLE::setDataRate(char rate) {
+
+    //Get the current register contents, so we don't clobber the power bit.
+    char registerContents = data_single_get(ADXL345_BW_RATE_REG);
+
+    registerContents &= 0x10;
+    registerContents |= rate;
+
+    return data_single_put(ADXL345_BW_RATE_REG, registerContents);
+
+}
+char ANGLE::getOffset(char axis) {     
+
+    char address = 0;
+
+    if (axis == ADXL345_X) {
+        address = ADXL345_OFSX_REG;
+    } else if (axis == ADXL345_Y) {
+        address = ADXL345_OFSY_REG;
+    } else if (axis == ADXL345_Z) {
+        address = ADXL345_OFSZ_REG;
+    }
+
+   return data_single_get(address);
+}
+
+int ANGLE::setOffset(char axis, char offset) {        
+
+    char address = 0;
+
+    if (axis == ADXL345_X) {
+        address = ADXL345_OFSX_REG;
+    } else if (axis == ADXL345_Y) {
+        address = ADXL345_OFSY_REG;
+    } else if (axis == ADXL345_Z) {
+        address = ADXL345_OFSZ_REG;
+    }
+
+   return data_single_put(address, offset);
+
+}
+int ANGLE::setTapDuration(short int duration_us) {
+
+    short int tapDuration = duration_us / 625;
+    char tapChar[2];
+     tapChar[0] = (tapDuration & 0x00FF);
+     tapChar[1] = (tapDuration >> 8) & 0x00FF;
+    return data_multi_put(ADXL345_DUR_REG, tapChar, 2);
+
+}
+int ANGLE::setTapLatency(short int latency_ms) {
+
+    latency_ms = latency_ms / 1.25;
+    char latChar[2];
+     latChar[0] = (latency_ms & 0x00FF);
+     latChar[1] = (latency_ms << 8) & 0xFF00;
+    return data_multi_put(ADXL345_LATENT_REG, latChar, 2);
+
+}
+int ANGLE::setWindowTime(short int window_ms) {
+
+    window_ms = window_ms / 1.25;
+    char windowChar[2];
+    windowChar[0] = (window_ms & 0x00FF);
+    windowChar[1] = ((window_ms << 8) & 0xFF00);
+   return data_multi_put(ADXL345_WINDOW_REG, windowChar, 2);
+
+}
+int ANGLE::setFreefallTime(short int freefallTime_ms) {
+     freefallTime_ms = freefallTime_ms / 5;
+     char fallChar[2];
+     fallChar[0] = (freefallTime_ms & 0x00FF);
+     fallChar[1] = (freefallTime_ms << 8) & 0xFF00;
+    
+    return data_multi_put(ADXL345_TIME_FF_REG, fallChar, 2);
+
+}
+ANGLE::kalman::kalman(void){
+    P[0][0]     = 0;
+    P[0][1]     = 0;
+    P[1][0]     = 0;
+    P[1][1]     = 0;
+    
+    angle       = 0;
+    bias        = 0;
+    
+    Q_angle     = 0.001;
+    Q_gyroBias  = 0.003;
+    R_angle     = 0.03;     
+}
+
+double ANGLE::kalman::getAngle(double newAngle, double newRate, double dt){
+    //predict the angle according to the gyroscope
+    rate         = newRate - bias;
+    angle        = dt * rate;
+    //update the error covariance
+    P[0][0]     += dt * (dt * P[1][1] * P[0][1] - P[1][0] + Q_angle);
+    P[0][1]     -= dt * P[1][1];
+    P[1][0]     -= dt * P[1][1];
+    P[1][1]     += dt * Q_gyroBias;
+    //difference between the predicted angle and the accelerometer angle
+    y            = newAngle - angle;
+    //estimation error
+    S            = P[0][0] + R_angle;
+    //determine the kalman gain according to the error covariance and the distrust
+    K[0]         = P[0][0]/S;
+    K[1]         = P[1][0]/S;
+    //adjust the angle according to the kalman gain and the difference with the measurement
+    angle       += K[0] * y;
+    bias        += K[1] * y;
+    //update the error covariance
+    P[0][0]     -= K[0] * P[0][0];
+    P[0][1]     -= K[0] * P[0][1];
+    P[1][0]     -= K[1] * P[0][0];
+    P[1][1]     -= K[1] * P[0][1];
+
+    return angle;
+}
+void ANGLE::kalman::setAngle(double newAngle) { angle = newAngle; };
+void ANGLE::kalman::setQangle(double newQ_angle) { Q_angle = newQ_angle; };
+void ANGLE::kalman::setQgyroBias(double newQ_gyroBias) { Q_gyroBias = newQ_gyroBias; };
+void ANGLE::kalman::setRangle(double newR_angle) { R_angle = newR_angle; };
+
+double ANGLE::kalman::getRate(void) { return rate; };
+double ANGLE::kalman::getQangle(void) { return Q_angle; };
+double ANGLE::kalman::getQbias(void) { return Q_gyroBias; };
+double ANGLE::kalman::getRangle(void) { return R_angle; };
+