Here's the code, will need to be modified to suit you own setup. Also, if anyone wants it, I've got a program that interfaces with FSX camera control and serial port, all you need to do is send a comma separated string of pitch, roll yaw and so on. Should make it easy for anyone wanting to control FSX camera from arduino.

Code:

#include <math.h>
#include <string.h>

#define gPin 0    
#define xAccePin 1
#define yAccePin 2
#define zAccePin 3
#define ledPin 7  
#define rledPin 7  
#define Vin 322
#define xOffset 5081
#define yOffset 5080
#define zOffset 5517


int gOffset = 0;//, xOffset = 0, yOffset = 0, zOffset = 0;
long gRaw = 0, xRaw = 0, yRaw = 0, zRaw = 0;
unsigned long timeold_fast = 0, timeold_med = 0;      
float rate = 0, rateold = 0, angle = 0, Azi = 0, Ele = 0, Roll = 0, AziOld = 0, EleOld = 0, RollOld = 0;
char tempc[10], printStr[50];



void A2Ddata(unsigned int n) {
  long tempG = 0, tempX = 0, tempY = 0, tempZ = 0;

  for(unsigned int k = 1; k <= n; k++){
    tempG += analogRead(gPin);  
    tempX += analogRead(xAccePin);
    tempY += analogRead(yAccePin);
    tempZ += analogRead(zAccePin);
    //delayMicroseconds(10);
  }
  gRaw = tempG*10/n;
  xRaw = tempX*10/n-xOffset;
  yRaw = tempY*10/n-yOffset;
  zRaw = tempZ*10/n-zOffset;
}


void setup() {
  pinMode(ledPin, OUTPUT);  
  pinMode(rledPin, OUTPUT);
  Serial.begin(38400);        

  analogReference(EXTERNAL);
  digitalWrite(rledPin,HIGH);
  delay(1000);
  //Find Gyro rate offset
  A2Ddata(10000);
  gOffset = gRaw*Vin/100;
  printStr[0]= '\0';
  digitalWrite(rledPin,LOW);
}



void loop() {

  if (millis()-timeold_fast > 10) {
    timeold_fast = millis();
    A2Ddata(8);

    //Calculate gyro turn rate
    rate = (gRaw*Vin/100-gOffset)*0.0150;

    if (abs(rate) > 2.5) {
      angle += (rateold+rate)*0.010;  //trapz intergration
    }
    rateold = rate;

    //Calculate elevation and roll angles
    Ele = (atan2(zRaw,xRaw)*57.296-90+EleOld)/2;
    Roll = (atan2(zRaw,yRaw)*57.296-90+RollOld)/2;

  }

  if (millis()-timeold_med > 50) {
    timeold_med = millis();
    // hysterisis dead band
    if (abs(Ele - EleOld) > 0.5) {
      EleOld = Ele;
    }
    else {
      Ele = EleOld;
    }

    if (abs(Roll - RollOld) > 0.5) {
      RollOld = Roll;
    }
    else {
      Roll = RollOld;
    }
    
// reset yaw angle to 0 when head is lowered > 60 degrees
    if (Ele < -60) {
      angle = 0;
    }
  
/*
// code to reduce gyro drift under steady conditions
    if (rate < 5) {
      if (rate > 0) {
        gOffset++;
      }
      else{
        gOffset--;
      }
    }
*/
    digitalWrite(ledPin, HIGH);

    strcat(printStr,floatToString(tempc,rate,2,6,false));
    strcat(printStr,",");
    strcat(printStr,floatToString(tempc,Ele,3,6,false));
    strcat(printStr,",");
    strcat(printStr,floatToString(tempc,Roll,3,6,false));
    strcat(printStr,",");
    strcat(printStr,floatToString(tempc,angle,3,6,false));
    Serial.println(printStr);

    printStr[0] = '\0';
    /*
    Serial.print(floatToString(tempc,rate,2,6,false));
     Serial.print(',');
     //Serial.println(floatToString(tempc,angle,2,6,false));  
     Serial.print(floatToString(tempc,Ele,2,6,false));
     Serial.print(',');
     Serial.print(floatToString(tempc,Roll,2,6,false));
     Serial.print(',');
     Serial.println(floatToString(tempc,angle,2,6,false));
     */
    digitalWrite(ledPin, LOW);  
  }

} 

Hi,

I didn't really write the code for interfacing with FSX. I took a SimConnect SDK example in Delphi, and modify it to take serial data, that's about it... If that's what you want to look at, I'll post it here...

Cheers,
-Z-

Well Done work..Does your code eliminate bias drift of the yaw gyro, exactly?

I have some questions.if you could answer i would be glad.In your code,

void A2Ddata(unsigned int n) {
 long tempG = 0, tempX = 0, tempY = 0, tempZ = 0;

 for(unsigned int k = 1; k <= n; k++){
   tempG += analogRead(gPin);  
 }
 gRaw = tempG*10/n;  ????
}



???? what the value you get ?   is it radians/sec or deg/sec ?   is tempG  given you as raw value of the sensor ?
especially i didnt understand the  temG*10/n ?    what this calc. do?




A2Ddata(8);   ????   why did you send 8 ?

   //Calculate gyro turn rate
   rate = (gRaw*Vin/100-gOffset)*0.0150;   ??

   if (abs(rate) > 2.5) {
     angle += (rateold+rate)*0.010;  //trapz intergration   ???
   }
   rateold = rate;


??  what this rate means ?
??? this should be the integration to calculate angle.




// code to reduce gyro drift under steady conditions
   if (rate < 5) {
     if (rate > 0) {
       gOffset++;
     }
     else{
       gOffset--;
     }
   }

Did you use this in your code?



I am sorry about these question, it is a lot. But really i need these because i am at the end of edge my thesis. Thanks your help

Thank you, i really appreciate your help.

Hey kersny,

Thanks for the link, I read about their filter, very interesting. I have been testing my own digital high pass filter to get rid of some of the drift. The problem is for pure panning motion, there is no accelerometer information available to correct the gyro, so their code will not work. I think it may be possible to correct drift when your head is not perfectly straight up though, but I have yet to get my head around it (so to speak ).

-Z-

waxweb,

It's not very difficult to put them together, but which parts do you have? The only difficulty is figuring out what where the gyro outputs the analogue signal, but that is different for different gyros.

-Z-