Is My Inertial Sensor Broken?

I got this sensor way early this year, and I haven’t used it until today. From what I’ve heard, these are supposed to be super accurate, but this is… decidedly not that.

@jpearman Is this how these are supposed to be working? If not, is there an RMA process for these, and if so how much would it cost to replace it? Would it just be better to buy a new one?

my inertial sensor is off by 3 or 4 degrees for every 360 degrees it turns. I just use a scale factor to correct it in code.


If the sensor is mounted at an angle, then it will report that angle, I can’t really see how well it’s mounted on your robot but it may well be correctly reporting 12 degrees of roll.

Remove the sensor and do some checks with it on a flat stable base, see the topic that @sarah_97963A linked.


I tried what was linked in that post, and I can’t get the button to turn red. I have the most recent VEXos update.

It also does this some times.

That’s what happens when it calibrates while moving. Basically, it thinks that the moving speed is actually still, and therefore holding it still makes it think it’s moving the other way. (i.e. recalibrate)

Ok, I got it reset, and it shows no drift right after calibration. However, it is definitely not measuring things correctly. Like, it got itself off by over 200 degrees after a bit of movement.

@jpearman Just to reiterate, this sensor is hardly used. It’s been turned on once before today.

In competition, is there any chance you would move your robot so rapidly in all 3 dimensions?

I also wouldn’t say what you did in the testing was only a bit of movement


I mean, it could very easily be accelerating that fast in 2 directions. Our auto routine rams into the goals to align itself.

Re-iterating what Josh said, are you sure the inertial is completely still while it calibrates for 2-3 seconds after starting the program? It’s a basic question, but good to clear up.

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Yes. It was sitting on the counter there.

Maybe put it on the robot and simulate an actual auto run, then measure how much drift there is?

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ours does some wierd stuff like that too. like I was testing it and all the sudden it was wayyy off. It does that same thing like yours did in the first vid, where as soon as you calibrate it, it automatically drifts to like 12-14 ish

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