Ticket #265 (new feature)

Opened 11 years ago

Last modified 8 years ago

can't find "Enable Pedal" footswitch (punch) setting on ffado-mixer for MOTU 896HD

Reported by: sireasoning Assigned to: jwoithe
Priority: major Milestone: FFADO 2.x
Component: ffado-mixer Version: FFADO 2.0.0
Keywords: enable pedal footswitch punch 896HD Cc: jwoithe
The device the bug applies to: MOTU 896HD


I can't seem to find the "Enable Pedal" section on the ffado-mixer on the MOTU 896HD. This is the section where a footpedal or switch can be activated for recording. You would also be able to define what keystrokes would be activated by the footswitch.

Change History

02/09/10 23:11:01 changed by sireasoning

  • cc set to jwoithe.

02/10/10 14:45:41 changed by jwoithe

  • owner changed from arnonym to jwoithe.
  • milestone set to FFADO 2.x.
  • device_name set to MOTU 896HD.

I have not heard of this 896HD feature until now, presumedly because you are the first person with a 896HD and a suitable footswitch to try FFADO. Consequently such a section will not be found in ffado-mixer.

To start with, could you describe what functions this footswitch can have? It presumedly connects to a dedicated input on the 896HD and causes some form of signal to be sent back to the PC (which is then used to trigger whatever events the user has configured, such as "record start" and so forth). Assuming this to be broadly correct we will need two components to make this function under FFADO.

Firstly we need to add support to the FFADO MOTU driver to detect the signal triggered by the footswitch. Adding support for this will be a little tricky unless you are willing to do some legwork since I do not own an 896HD nor do I have physical access to an 896HD. In short, I need to know out how the footswitch action is transmitted to the PC. Once I know that I can integrate this into FFADO. If you are willing to go digging for this for me please contact me off-list and we'll talk through the various options.

Secondly, once FFADO knows how to receive the pedal events it needs some way to communicate the configured action to whatever software it is that you are running. This may prove to be the more involved process since at present AFAIK FFADO does not have any mechanism we could use for this which would be immediately accessible to other applications (that is, requiring no changes to the applications). I will ponder this side of the equation and in the meantime others may chime in with suggestions.

Technically there is a third component - that of configuring the actions to trigger. Until the details of the first two points are clearer it's not possible to work out where this might reside. I have a suspicion that it might not end up being in ffado-mixer due to the complete separation of ffado-mixer from the streaming system. Since the footswitch signals will almost certainly be transmitted in a subchannel of the main data stream this becomes an issue. It's not worth worrying about this though until the previous issues are sorted.

02/10/10 19:43:29 changed by sireasoning

It appears to be a simple setup They have just three options: a checkbox for "enable Pedal"

Then a place to set the keystroke associated with "Pedal Down" and a keystroke to associate with "Pedal Up"

The default is for their software and "Pedal Down" is set to "3" and "pedal Up" is set to "none"

If it is as simple as it looks, it would appear that all you need to know is the keystroke. How do I contact you off list?

02/10/10 19:57:28 changed by jwoithe

Thanks for the additional information. From what you describe, it seems that the MOTU does just sent two events: pedal down and pedal up. These are then translated into keystrokes on the PC. So the first part of the task is to work out how the MOTU indicates to the PC that the pedal has gone done and come up.

Contacting me off-list: a good question. Perhaps go to my homepage at http://www.physics.adelaide.edu.au/~jwoithe/

You'll find a link to my email address right at the very bottom. If there's a problem let me know.

02/10/10 20:40:43 changed by sireasoning

I sent an email, let me know if you got it....

02/10/10 21:06:12 changed by jwoithe

Got it - thanks. Will follow up privately and post back here when relevant.

03/27/12 07:56:35 changed by jwoithe

Thanks to a loan 896HD a year or so ago, I now know how the footswitch signal is sent to the PC. There things have rested, mostly because I forgot all about it. I will take another look at this and see if it's possible to easily set up a receiver for these events within the context of FFADO. I suspect a standalone receiving application will be the go, but we'll see.

03/30/12 23:26:02 changed by sireasoning