Problems with the frc-characterization tool

Hello all,

My team and I are trying to use the frc-characterization tool to characterize our drive train and have run into multiple problems.

First of all, in the Units per rotation field. We have gone with the meters option in UnitType, but are quite uncertain about what value we should put in the units per rotation. In the docs it says:

how many of the previously specified units are recorded per rotation of the shaft.

but which shaft do they mean? the motor shaft or the output shaft? In the example, there is no mention of gearing.

such as a wheel with a 3-inch diameter can be converted to 9.42 inches per rotation.

So I guess I am asking if we are using a 0.1524 m diameter wheel, whether I should put 0.15243.14 or 0.15243.14*gearing (1/9 in our case).

Secondly, we don’t know what value to put in the Edges-per-Revolution section.
We are using Flacon 500 motors. My best guess is that since there are no edges in Falcon 500, the encoderEPR will be 2048. Is that correct?

Many thanks in advance for any help provided!

This is flexible; there’s a gearing field in the tool that you can use if desired, or else you can wrap your gearing into the conversion factor. The documentation hasn’t been updated to reflect this quite yet.

This is correct. I regret the choice to use the term “edges” at this point; I think the terminology here is just irreparably mangled and we’ve not made it any better.

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Thank you very much for the fast reply!
So in the first question, I can just put 0.1524*pi and in the gearing section put 1/9?

And in the second question do I need to factor in the gearing? Like is the 2048 answer the final answer, or do I need to put 2048*1/9?
Just want to be sure that I will not drag on a mistake further, thanks again

If you add your gearing to the gearing spot in the config, then you don’t have to worry about including it into units per rotation or EPR


Thank you all very much! Very appreciated

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