Fix NimBLEHIDDevice output report returning incorrect characteristic.

[h2zero]

The input and output report characteristics share the same UUID and the getOutputReport was returning the input report characteristic. This change will return the correct characteristic by finding it with the index parameter.

Fixes #804

[afpineda]

Hi. I know v2.1.1 has been released, but I think this bug is not fixed at all.
You can have more than one output report. The same applies to getFeatureReport() which was not fixed.
The implementation in v1.4.x was OK.

Note: The output report characteristic is optional and should only be created after the input report characteristic.

This creates temporal coupling which is bad both for the user and the maintainer. There should be another fix.

Another related problem:

If you return the same characteristic for any reportID, you have no way to install a different characteristic callback for each of them.

[h2zero]

Hi @afpineda, thanks for the feedback.

You can have more than one output report.

I did not know this.

The PR was only to address the issue brought up in #804, where it was confirmed to resolve the issue.

I'm starting to think that the best fix is to move this class into it's own repo/library as I know nothing of HID specs and have no use or interest for this myself. The only reason this is here is because it was in the original library so I converted it to use NimBLE.
If you would like to open a repo and host this I would be happy to provide a link to it from here instead of hosting the code.

[afpineda]

You can have more than one output report.

I did not know this.

In fact, you can have more than one report of any kind (up to 255), including input reports.

I'm starting to think that the best fix is to move this class into it's own repo/library as I know nothing of HID specs and have no use or interest for this myself. The only reason this is here is because it was in the original library so I converted it to use NimBLE. If you would like to open a repo and host this I would be happy to provide a link to it from here instead of hosting the code.

Don't get discouraged by a few bugs. You are doing a good job!
Believe me, I make extensive use of the NimBLEHIDDevice class and I can say that it works well.
Moving it to another repo is a bad idea. You force your users into another software dependency, and dependency management is a nightmare. But don't worry, I will help with this via pull request.

[h2zero]

Not discouraged, just a bit weary. I get in trouble any time I touch this class lol. Like I said this is not my area of knowledge, just thought it would be better if someone that knows more about it maintained it.