Feature Request: Function to return how long a track is in ms

[LillyWho]

I'm looking to use the board in a project where it would be useful to know how long a track is, in order to time playing other tracks afterwards. It's supposed to be a sound board for a train, so things like sounds of a horn with hit - loop - fade out would be made a lot easier to implement. Right now this could sort of be done, but only very awkwardly by determining whether a specific track is playing, when it has started playing, and whether it has then stopped playing. Querying the length of a track, timing when playing the track has started and counting out a timeout would be much more convenient.

[robertsonics]

Thanks for the suggestion. This would involve changes to both sides - the firmware as well as the library - and it would also mean dead-reckoning the end of the file. I would argue that the current method of track reporting and polling is more accurate and really not any more awkward than waiting a certain amount of time and then trusting that the track has just stopped. I'm not against adding this functionality, but I don't see it as a priority since there's already an existing way to achieve the result. I'm currently working on the release of the new WAV Trigger Pro (perhaps of interest for model trains due to its significantly smaller size) but will revisit this when I get time.

[LillyWho]

I would argue that the current method of track reporting and polling is more accurate and really not any more awkward

May I ask what your current intended implementation is for this?

[robertsonics]

Sure. You call

wTrig.setReporting(true)

once during setup. Then in your mail loop, you periodically call:

wTrig.update();
wTrig.isTrackPlaying(trackNum);

The period is basically your polling rate - how often you want to check if the trackNum has completed. You can do this as often as you like without it burdening the serial comms to the WAV Trigger. With setReporting true, the WAV Trigger will send a message when any track starts or stops which is put in a serial buffer from a behind-the-scenes interrupt. Update() and isTrackPlaying() just pull from the buffer and update Arduino's internal track states.

The advanced example sketch included in the library demonstrates this.

Hope this helps.