Using the gyro sensor more than once?


#1

So I’m using the gyro sensor to turn and to compensate for veering off course when going straight. But whenever I use it a second time in my code it doesn’t do anything and skips that section of code entirely. Do I have to do a gyro.isCalibrating before every time I use it. Any help would be much appreciated, thanks :).


#2

When your program is executed the gyro will calibrate, that takes about 1 second and the robot should not be moving when that happens. While the gyro is calibrating the gyro.isCalibrating method will return true. Once the gyro is calibrated it should not be necessary to calibrate again.

The gyro will return 0 degrees after calibration has finished, the gyro will then return values in the range +/- 360 degrees when it turns. It’s up to your code to handle any roll over conditions with the current version of vexos, we will change that and also provide a reset (meaning reseting the value to 0, not a full recalibration) in a future vexos/VCS release as it seems so many users are having trouble with that.

Perhaps post the section of code causing trouble and we can suggest improvements.


#3

Im not able to post the code at the time being but I will first thing in the morning, thanks for the response!


#4

@abennett5139 Did you post code ? It looks like you updated this thread 2-3 hours ago but I don’t see anything new here.


#5

I thought I did I’ll post it in smaller sections and see if that helps it


#6

Here’s the gyro calibration

Gyro.startCalibration(500);
                        
            task::sleep(10);
    
            while( Gyro.isCalibrating() )
            {
                task::sleep(500);
            }

#7

Here’s the function that accounts for the veering of the drive train

//Drives the bot forward in centimeters using the gryo to compensate for veering
void DriveFWDforCMGyro (double TravelTarget, int Velocity)
{
    //Formula to deride the distance needed to go in centimeters
    Velocity *= 2;
    
    double DegreesToRotate = (360*TravelTarget)/Circumference;


    //Drive the bot forward for the distance specified in centimeters with the gyro compensating for veering
    while(FL_Drive.rotation(rotationUnits::deg) <= DegreesToRotate)
    {
        while (FL_Drive.rotation(rotationUnits::deg) <= DegreesToRotate*.30)
        {
            while (Gyro.value(rotationUnits::deg) < -0.01)
            {
                FL_Drive.spin(directionType::fwd,Velocity*.5,velocityUnits::rpm);
                FR_Drive.spin(directionType::fwd,Velocity*0.46,velocityUnits::rpm);
                BL_Drive.spin(directionType::fwd,Velocity*.5,velocityUnits::rpm);
                BR_Drive.spin(directionType::fwd,Velocity*0.46,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while (Gyro.value(rotationUnits::deg) > 0.01)
            {
                FL_Drive.spin(directionType::fwd,Velocity*0.485,velocityUnits::rpm);
                FR_Drive.spin(directionType::fwd,Velocity*.5,velocityUnits::rpm);
                BL_Drive.spin(directionType::fwd,Velocity*0.485,velocityUnits::rpm);
                BR_Drive.spin(directionType::fwd,Velocity*.5,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while ( Gyro.value(rotationUnits::deg) > -0.01 &&  Gyro.value(rotationUnits::deg) < 0.01)
            {
                FL_Drive.spin(directionType::fwd,Velocity*.5,velocityUnits::rpm);
                FR_Drive.spin(directionType::fwd,Velocity*.5,velocityUnits::rpm);
                BL_Drive.spin(directionType::fwd,Velocity*.5,velocityUnits::rpm);
                BR_Drive.spin(directionType::fwd,Velocity*.5,velocityUnits::rpm);
                task::sleep(125);
            }
        }
        
        while (FL_Drive.rotation(rotationUnits::deg) <= DegreesToRotate*.65)
        {
            while (Gyro.value(rotationUnits::deg) < -0.01)
            {
                FL_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
                FR_Drive.spin(directionType::fwd,Velocity*0.71,velocityUnits::rpm);
                BL_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
                BR_Drive.spin(directionType::fwd,Velocity*0.71,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while (Gyro.value(rotationUnits::deg) > 0.01)
            {
                FL_Drive.spin(directionType::fwd,Velocity*0.735,velocityUnits::rpm);
                FR_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
                BL_Drive.spin(directionType::fwd,Velocity*0.735,velocityUnits::rpm);
                BR_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while ( Gyro.value(rotationUnits::deg) > -0.01 &&  Gyro.value(rotationUnits::deg) < 0.01)
            {
                FL_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
                FR_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
                BL_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
                BR_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
                task::sleep(125);
            }
        }
        
        while (FL_Drive.rotation(rotationUnits::deg) <= DegreesToRotate)
        {
            while (Gyro.value(rotationUnits::deg) < -0.01)
            {
                FL_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
                FR_Drive.spin(directionType::fwd,Velocity*0.96,velocityUnits::rpm);
                BL_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
                BR_Drive.spin(directionType::fwd,Velocity*0.96,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while (Gyro.value(rotationUnits::deg) > 0.01)
            {
                FL_Drive.spin(directionType::fwd,Velocity*0.985,velocityUnits::rpm);
                FR_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
                BL_Drive.spin(directionType::fwd,Velocity*0.985,velocityUnits::rpm);
                BR_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while ( Gyro.value(rotationUnits::deg) > -0.01 &&  Gyro.value(rotationUnits::deg) < 0.01)
            {
                FL_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
                FR_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
                BL_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
                BR_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
                task::sleep(125);
            }
        }
        
    }
    

    //Wait for 100 miliseconds so the bot does not move off course

    task::sleep(100);
    
    FL_Drive.stop();  
    FR_Drive.stop();
    BL_Drive.stop();  
    BR_Drive.stop();
}

#8

Here’s the reverse version of that function

//Drives the bot reverse in centimeters using the gryo to compensate for veering
void DriveREVforCMGyro (double TravelTarget, int Velocity)
{
    //Formula to deride the distance needed to go in centimeters
    Velocity *= 2;
    
    double DegreesToRotate = (360*TravelTarget)/Circumference;


    //Drive the bot forward for the distance specified in centimeters with the gyro compensating for veering
    while(FL_Drive.rotation(rotationUnits::deg) <= DegreesToRotate)
    {
        while (FL_Drive.rotation(rotationUnits::deg) <= DegreesToRotate*.30)
        {
            while (Gyro.value(rotationUnits::deg) < -0.01)
            {
                FL_Drive.spin(directionType::rev,Velocity*.5,velocityUnits::rpm);
                FR_Drive.spin(directionType::rev,Velocity*0.46,velocityUnits::rpm);
                BL_Drive.spin(directionType::rev,Velocity*.5,velocityUnits::rpm);
                BR_Drive.spin(directionType::rev,Velocity*0.46,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while (Gyro.value(rotationUnits::deg) > 0.01)
            {
                FL_Drive.spin(directionType::rev,Velocity*0.485,velocityUnits::rpm);
                FR_Drive.spin(directionType::rev,Velocity*.5,velocityUnits::rpm);
                BL_Drive.spin(directionType::rev,Velocity*0.485,velocityUnits::rpm);
                BR_Drive.spin(directionType::rev,Velocity*.5,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while ( Gyro.value(rotationUnits::deg) > -0.01 &&  Gyro.value(rotationUnits::deg) < 0.01)
            {
                FL_Drive.spin(directionType::rev,Velocity*.5,velocityUnits::rpm);
                FR_Drive.spin(directionType::rev,Velocity*.5,velocityUnits::rpm);
                BL_Drive.spin(directionType::rev,Velocity*.5,velocityUnits::rpm);
                BR_Drive.spin(directionType::rev,Velocity*.5,velocityUnits::rpm);
                task::sleep(125);
            }
        }
        
        while (FL_Drive.rotation(rotationUnits::deg) <= DegreesToRotate*.65)
        {
            while (Gyro.value(rotationUnits::deg) < -0.01)
            {
                FL_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
                FR_Drive.spin(directionType::rev,Velocity*0.71,velocityUnits::rpm);
                BL_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
                BR_Drive.spin(directionType::rev,Velocity*0.71,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while (Gyro.value(rotationUnits::deg) > 0.01)
            {
                FL_Drive.spin(directionType::rev,Velocity*0.735,velocityUnits::rpm);
                FR_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
                BL_Drive.spin(directionType::rev,Velocity*0.735,velocityUnits::rpm);
                BR_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while ( Gyro.value(rotationUnits::deg) > -0.01 &&  Gyro.value(rotationUnits::deg) < 0.01)
            {
                FL_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
                FR_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
                BL_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
                BR_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
                task::sleep(125);
            }
        }
        
        while (FL_Drive.rotation(rotationUnits::deg) <= DegreesToRotate)
        {
            while (Gyro.value(rotationUnits::deg) < -0.01)
            {
                FL_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
                FR_Drive.spin(directionType::rev,Velocity*0.96,velocityUnits::rpm);
                BL_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
                BR_Drive.spin(directionType::rev,Velocity*0.96,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while (Gyro.value(rotationUnits::deg) > 0.01)
            {
                FL_Drive.spin(directionType::rev,Velocity*0.985,velocityUnits::rpm);
                FR_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
                BL_Drive.spin(directionType::rev,Velocity*0.985,velocityUnits::rpm);
                BR_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
                task::sleep(125);
            }
        
            while ( Gyro.value(rotationUnits::deg) > -0.01 &&  Gyro.value(rotationUnits::deg) < 0.01)
            {
                FL_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
                FR_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
                BL_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
                BR_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
                task::sleep(125);
            }
        }
        
    }
    

    //Wait for 100 miliseconds so the bot does not move off course

    task::sleep(100);
    
    FL_Drive.stop();  
    FR_Drive.stop();
    BL_Drive.stop();  
    BR_Drive.stop();
}

#9

Here’s the turning functions

//Turns the bot counter clockwise using the gyro sensor
void GyroTurnCCW (double TurnTarget, int Velocity)
{
    //Assignment to convert the velocity from percent to rpm
    Velocity *= 2;
    
    //Turning counter clockwise the gyro value is negative
    //While the gyro value is greater than 40% of the turn target turn the robot 100% of speed
    while (Gyro.value(rotationUnits::deg) >= TurnTarget * .40)
    {
        FL_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
        FR_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
        BL_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
        BR_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
    }
    
    //While the gyro value is greater than 75% of the turn target turn the robot 75% of speed
    while (Gyro.value(rotationUnits::deg) >= TurnTarget * .75)
    {
        FL_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
        FR_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
        BL_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
        BR_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
    }
    
    //While the gyro value is greater than the turn target turn the robot at half speed
    while (Gyro.value(rotationUnits::deg) >= TurnTarget)
    {
        FL_Drive.spin(directionType::fwd,Velocity*.50,velocityUnits::rpm);
        FR_Drive.spin(directionType::rev,Velocity*.50,velocityUnits::rpm);
        BL_Drive.spin(directionType::fwd,Velocity*.50,velocityUnits::rpm);
        BR_Drive.spin(directionType::rev,Velocity*.50,velocityUnits::rpm);
    }
    
    FL_Drive.stop();  
    FR_Drive.stop();
    BL_Drive.stop();  
    BR_Drive.stop();
}

//Turns the bot clockwise using the gyro sensor
void GyroTurnCW (double TurnTarget, int Velocity)
{
    //Assignment to convert the velocity from percent to rpm
    Velocity *= 2;
    
    //Turning clockwise the gyro value is positive
    //While the gyro value is less than 40% of the turn target turn the robot 100% of speed
    while (Gyro.value(rotationUnits::deg) <= TurnTarget * .40)
    {
        FL_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
        FR_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
        BL_Drive.spin(directionType::rev,Velocity,velocityUnits::rpm);
        BR_Drive.spin(directionType::fwd,Velocity,velocityUnits::rpm);
    }
    
    //While the gyro value is less than 75% of the turn target turn the robot 75% of speed
    while (Gyro.value(rotationUnits::deg) <= TurnTarget * .75)
    {
        FL_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
        FR_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
        BL_Drive.spin(directionType::rev,Velocity*.75,velocityUnits::rpm);
        BR_Drive.spin(directionType::fwd,Velocity*.75,velocityUnits::rpm);
    }
    
    //While the gyro value is less than the turn target turn the robot at 50% of speed
    while (Gyro.value(rotationUnits::deg) <= TurnTarget)
    {
        FL_Drive.spin(directionType::rev,Velocity*.50,velocityUnits::rpm);
        FR_Drive.spin(directionType::fwd,Velocity*.50,velocityUnits::rpm);
        BL_Drive.spin(directionType::rev,Velocity*.50,velocityUnits::rpm);
        BR_Drive.spin(directionType::fwd,Velocity*.50,velocityUnits::rpm);
    }
    
    FL_Drive.stop();  
    FR_Drive.stop();
    BL_Drive.stop();  
    BR_Drive.stop();
}


#10

@jpearman


#11

ok, thanks, I’ll look later. I think it was a forum glitch that stopped posts displaying.
btw

Gyro.startCalibration(500);

there is no need to pass a number to Gyro.startCalibration, the number is not the calibration time (as such, valid values would be 0, 1 or 2 corresponding to 1, 2 or 4 seconds), it means something completely different (it’s a scale factor) so I’m surprised your gyro is returning accurate values.


#12

Oh ok so I don’t need any number in that?

But would that hinder my gyro from only working once, and just skipping gyro code after that?


#13

Were these codes written is C++, C++ Pro, Or Robot C. If this is not C++, could someone translate it to C++? All help will be appreciated!


#14

This is C++