What is the difference between a gyroscope chip and an accelerometer chip?
A gyroscope measures its actual orientation, in degrees for example. (I think)
An accelerometer only measures acceleration. But they can measure angles indirectly by sensing gravitational acceleration.
A gyroscope measures its actual orientation, in degrees for example.
A gyro measures rate of change (just like an accelerometer), but of angular not linear velocity.
So, instead of ms-2, it measures radians per second.
By itself, it cannot measure absolute orientation.
Perhaps a couple examples would help:
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If you rotate a gyro at constant speed, it will output angular velocity (degrees per second or rotations per minute if you like). When you stop rotation, output drops to zero. The output is always proportional to speed of rotation. If you integrate the output (add successive values) you can track absolute angular position. No rotation = zero, fast rotation = high value.
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If you rotate an accelerometer at constant speed, it wil output zero. When you stop rotation, output increases proportional to how fast you stop. The output is always proportional to change of speed. Constant speed = zero, quick stop (or start) = high value.
If you like math, you may find the following interesting:
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A plot of the integral of an accelerometer has the characteristic of a gyro.
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A plot of the derivative of a gyro has the characteristic of an accelerometer.
An accelerometer is now a common component popularised by the likes of the Wii and the iPhone (and every phone that came out after the iphone). That makes them cheap enough for hobbyists like us to use.
A gyroscope isn't used much in gadgetry yet. The new iPhone has them so give it five years and they'll be available cheaply.
If you rotate an accelerometer at constant speed, it wil output zero
That depends on how far from the axis of rotation the accelerometer is mounted, viz, a centrifuge.
A gyroscope isn't used much in gadgetry yet.
Model helicopters have been using them for some years now.
Model helicopters have been using them for some years now.
Yes but they serve a purpose and model helicopters aren't cheap.
I meant more as a pointless add-on like phones having two cameras, accelerometers, media player capabilities, etc etc.
Accelerometers aren't pointless in gadgets! Without accelerometers, there'd be no doodle jump!
Oh and sorry for the incorrect explanation of a gyro. Thanks for the clarification.
Here is something that would be just about impossible without BOTH a GYRO and ACCELEROMETER
Yeah, not cheap... you have to plop down ~$200 just to start DIY tinkering with a project like this...
Check out the parts list---> Arduino Powered
Not as pointless in phones as you think...
- Screen Orientation adjustment
- User Input method
Best advantage for being used in phones... (already mentioned) It makes the parts more mainstream and therefore cheaper to us hobbyists eventually.
Orientating the display to match the phone's orientation is a load of crap. The number of times I actually want my screen to go sideways pales into insignificance compared with the number of times I've been laid down and my phone changes the screen.