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[on:]

hi i am building a balancing robot and need to output the current angle of the gyro in degrees. all i can manage to do is get the gyro to output voltages which is only for movement when the gyro is moved at speed but then resets to the original voltage. the code i am using can be seen below. thanks

int y;
int gyroPin = 0;

void setup ()
{
  Serial.begin(9600);
}

void loop()
{

  y = analogRead(gyroPin);

 
  Serial.println(y);
  delay(250);
}

[Reply #1 on:]

You can't measure angle with this sort of gyro, its a "rate gyro" - all you get is a signal proportional to rotation rate.

[Reply #2 on:]

You can find a comprehensive tutorial on how to use the IDG500 and Arduino here:

http://arduinorobotics.blogspot.com/

Hope it helps!

[Reply #3 on:]

Hello

I think you can take a look at this:
http://arduino.cc/playground/Main/Gyro

You can't measure angle with this sort of gyro, its a "rate gyro" - all you get is a signal proportional to rotation rate.

Yes it is a gyrometer, but you can evaluate the angle by making an integration of the angular speed.

Hope that it will help you

[Reply #4 on:]

Hello

I think you can take a look at this:
http://arduino.cc/playground/Main/Gyro

You can't measure angle with this sort of gyro, its a "rate gyro" - all you get is a signal proportional to rotation rate.

Yes it is a gyrometer, but you can evaluate the angle by making an integration of the angular speed.

Hope that it will help you

I'll be clearer - you can't measure _absolute_ angle with a rate gyro.  Integrating the signal gives you a drifting measure of _change_ of angle, and due to non-linearity you get different measurements at different rates too (although this imperfection is usually within a few percent).

Philosophically all gyroscopes are rate gyros since we can't make a perfect one, but there's a real world difference between a ring laser gyro that doesn't need drift correction during the whole journey and a MEMS one that needs it every 10 seconds!

[Reply #5 on:]

I'll be clearer - you can't measure _absolute_ angle with a rate gyro.  Integrating the signal gives you a drifting measure of _change_ of angle, and due to non-linearity you get different measurements at different rates too (although this imperfection is usually within a few percent).

OK i apologize for my unclear post   That is the reason why i used the "evaluate" word, but i should have been more precise, thank you to correct me

So i also be clearer, you can output the change of angle in degrees by integration of gyro angular rate data but with high drift due to the gyrometer technology (MEMS). This measure is non-reliable.

Also for your balancing robot application, i think you need to combined information coming from an accelerometer and a gyrocope (i'm not an expert so correct me if i'm wrong)

hi i am building a balancing robot and need to output the current angle of the gyro in degrees.

Is it possible to give us more precisions on your project ?

Philosophically all gyroscopes are rate gyros since we can't make a perfect one, but there's a real world difference between a ring laser gyro that doesn't need drift correction during the whole journey and a MEMS one that needs it every 10 seconds!

Yes, this is also the reason why Inertial Navigation Systems are not, for the moment ,made with MEMS sensors

[Reply #6 on:]

i think you need to combined information coming from an accelerometer and a gyrocope

Exactly.  A gyro can't be counted on to tell you where 'down' is.  (at least, the cheap ones I play with)

 An accelerometer (3 axis, especially) can.

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