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Author Topic: single axis gyro breakout  (Read 883 times)
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Hi,

I'm looking to buy a single axis gyro (can also be 2 or 3, but only need to measure the Y-axis) that can detect up to 1200 deg/s (it's for a device which has an 'arm' and can move only back and forth, but quite fast. Sparkfun's Accelerometer and Gyro buying guide is not helpfull as most of the products in there are not updated and not sold anymore.

Anyone has any suggestions? Oh, and bytheway: does it really matter which axis' are measured? i can just position the gyro differently right? or does that really not work? if not, then i need to measure angular velocity rotating a Y-axis (the arm moves straight away from you).

Thanks for any tips or gyro's i can buy!

Michael
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Sure, you can set the gyro for the right axis.

If you use a gyro that is used a lot, you end up with 3-axis. But that's no problem.

If you read the datasheet of the MPU-6000 or MPU-6050, you can see that the range is programmable up to 2000 degrees/second.
Also the ITG-3200 is up to 2000 degrees/second.

Is this what you are looking for?
« Last Edit: May 10, 2012, 07:05:31 pm by Krodal » Logged

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Usually 1-axis gyros are yaw-axis (Z).  2-axis are pitch/roll (X, Y).  A yaw-axis breakout can be mounted at right-angles to your circuit board with 90degree headers if you need Y-axis from it.

Having decided whether you want analog or digital output device select the cheapest (1, 2 or 3) axis gyro breakout that covers your 1200deg/s range?
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Thanks guys.

@Krodal: good to know that it doesn't matter, as long as i install it so i get it to read the direction i want smiley-grin

@MarkT: Thanks, i've seen some examples of that, like on the 5DOF- or 9DOF boards.
Hmm, if i want to calculate linear velocity from angular velocity, what would be the best gyro to buy? Analog or digital?
Eventually i need the linear velocity to calculate a ballistic path (article is in dutch but see the formula):
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The best gyro is just a gyro that meets your speficiations.
Whether it is analog or digital, that is just the interface.
For an analog sensor, you only have to call analogRead() and you got the value.
The digital sensors need a library for the communication with the sensor. The digital versions of a sensor have often a little better specs.

Some sensors have so many options, and can be programmed for the range for example, that only a digital communication can do all of that.
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Thanks Kordal, completely clear. i'll have to balance between ease of use and functionality then.
Have any links where i can buy Gyro's? Sparkfun is okay, but they have mostly expensive ones and only a few go as far as 1200 deg/sec...

Thanks!
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I did bytheway find a dutch prototyping store (www.iprototype.nl) which sells this
dual axis gyro (seems ok!). However in the datasheet it says it can go to 300 deg/sec (amplified 4x) or 1200 deg/sec (unamplified).

Is the signal still detectable by arduino if it's unamplified? because then this gyro would be perfect for the job!

Thanks!
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Unamplified the signal could be read by the Arduino.

This device doesn't seem very accurate though. It has a +/- 1200 degree range and outputs .00083V per deg/s. Multiplying those results in a 0 to 2V range. That's a bit less than 2/3rds of the accuracy from the 10-bit accuracy of the ADC on the ATmegas (when run with a 3.3V reference).
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Thanks Kordal, completely clear. i'll have to balance between ease of use and functionality then.
Have any links where i can buy Gyro's? Sparkfun is okay, but they have mostly expensive ones and only a few go as far as 1200 deg/sec...

Thanks!

I know there are a few gyro / accelerometer / IMU breakouts on eBay...
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@Chagrin can you explain this a bit more in-depth? I understand the principle of ADC/DAC, however
I do not understand the process of multiplication from 0V-2V and mostly, why it is inaccurate!

I need to use it to measure angular velocity in a short time, say 0.08 seconds (the arm is being hit)

Thanks smiley
« Last Edit: May 14, 2012, 06:18:18 am by supermaggel » Logged

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