Hi Will (I guess),

Thanks for the reply. I was "fooled" the same way by my MIDI monitor software not showing anything different. I guess it just doesn't show the active sense signal because it would result in a constant stream of 4 events every second, making it hard to monitor "real" MIDI events. I really hope that the Active Sense signal is THE problem because this would possibly lead to a solution using a firmware update. I like the MIDI mobilizers, but it kinda sucks am I unable to use my best controller keyboard (Edirol PCR-M80) and one of my favorite synth modules (Korg 01R/W) with it. Lets hope the tech guys at Line 6 can take a look at this. :-)

Hello Hugo,

The Active Sense signal itself is not so much "hindering" the things I want to do but I think it is actually disabling the MIDI Mobilizer at some point, most probably the software/firmware inside it.

As mentioned above, the MIDI Mobilizer stops functioning entirely after a while when used with two of my three controller keyboards; the Edirol PCR-M80 and the M-Audio Keystayion 49e. It also doesn't particularly "like" my Korg 01R/W module, which manages to "crash" the MIDI Mobilizer from time to time when doing SysEx dumps (to the MIDI Memo Recorder).

I have no problems whatsoever when using my old StudioLogic CMK 149 controller keyboard or any other sound module or my sequencer.

The most suspicious thing the two controller keyboards and the Korg 01R/W have in common (after comparing all the MIDI implementation charts) is that they all send out an Active Sense signal and all my other gear is not. This is also (as you wrote) most probably the signal that makes the MIDI Mobilizer LED flash constantly, even when not touching or playing anything.

So it's not actually this signal itself that is preventing me from using the MIDI Mobilizer, but when any of these Active Sensing devices is connected, the MIDI Mobilizer just stops functioning after a short while (few minutes or sometimes not even a minute).

By "stops functioning" I mean that the LED indicates an incoming MIDI event (changes from the steady 4 times a second flashing to an irregular flashing that matches events I send to it), but the app used a that moment isn't detecting anything incoming anymore even though the MIDI Mobilizer itself IS detected. Apps I tried (and all behave like this) are Nano Studio, Music Studio and the Line 6 MIDI Memo Recorder. These all indicate they "see" the MIDI Mobilizer, but no MIDI data get "through" even though the MIDI Mobilizer itself (the LED) is clearly indicating something is going in.

So, to cut this way too long story short (trying to be complete here); since this problem occurs on both my MIDI Mobilizers, with three different apps, on both my iPhones (3G and 3GS) and my iPad but only when used in conjunction with a device that uses Active Sensing the one and only conclusion I could come up with is that the software/firmware inside the MIDI Mobilizer somehow crashes or otherwise gets disabled, preventing it from passing the incoming  signal on the MIDI in to the device on the dock connector side.

To be complete for troubleshooting's sake, I have:

Two MIDI Mobilizers with the latest updates according to the MIDI Memo Recorder app.

One iPhone 3G, not jailbroken, with iOS 4.2.1 (8C148)

One iPhone 3GS, jailbroken, with iOS 4.1 (8B117)

One iPad, not jailbroken, with iOS 4.2.1 (8C148)

Normally I connect all my stuff through an Opcode 8Port/SE interface, but for testing and troubleshooting I used direct connections also.

I switched all four of my MIDI Mobilizer cables to the MIDI-In to ensure I was not using a faulty cable.

Today I purchased a second-hand (obviously) Roland D-20, next Thursday I'll be getting a Yamaha DJX keyboard. I'll do some testing with these keyboards too when I find the MIDI implementation charts of these. Meanwhile, if you need any further information or testing from me, please just let me know! Maybe I'll make a little video showing the problem one of these days.

Thanks.

Some more info. Sorry if all these messages seem like spamming, I just want to be as complete as possible, so I am constantly testing and monitoring all kinds of things, using different hardware and setups.

Today I connected my Roland D-20 to the MIDI Mobilizer. According to the MIDI Implementation Chart the D-20 does not send out Active Sensing. It does however send out a constant MIDI Clock Signal, so the LED on the MIDI Mobilizer stays on permanently.

When connecting the D-20 directly to the MIDI Mobilizer, I can send as much program change events as I want, even while playing notes. This has no effect on the functioning of the MIDI Mobilizer and everything is working like expected for as long as I want.

When connecting the D-20 THROUGH the Edirol PCR-M80 (so introducing the Active Sense again) the MIDI Mobilizer stops functioning again after sending some program changes from the Roland D-20, either while playing, or just sending Program Changes while NOT hitting any notes.

I think this once again proves that there is some problem with the Active Sense signal COMBINED with other MIDI events (other than note on/off events).

The Active Sense by itself does NOT cause a problem. I can leave the Edirol controller connected to the MIDI Mobilizer for minutes, constantly "feeding" it an Active Sense Signal, and it still works like expected when I play some music. As soon as I start sending Program Changes with it, it somehow "dies" again. Sending program changes from other controllers does not affect the MIDI Mobilizer, so it only causes problems when send along with an Active Sense signal.

Furthermore, I've been testing all kinds of Controller Codes and this does not seems to affect the MIDI Mobilizer. But one of my controller knobs on the Edirol was sending out a Channel Aftertouch message and this IMMEDIATELY disables the MIDI Mobilizer again.

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: Edit 1

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Now things get a little weird...

I was thinking of a way to "strip" the Active Sense signal out of the MIDI data send out by the Edirol, but I am a little limited in the hardware available to me. Just for testings sake, I put a Anatek Pocket Merge box between the Edirol Controller and the MIDI Mobilizer.

The MIDI-In LED on the MIDI Mobilizer started to blink at twice the rate it does without the Pocket Merge box. It almost seemed like it was now receiving two Active Sense signals? However... the MIDI Mobilizer does NOT "crash" anymore when putting the Anatek MIDI Merge box between the Edirol controller and the MIDI Mobilizer!

So I am now looking for a way to determine if the MIDI Merge box is in fact stripping the Active Sense from the signal. I only have some MIDI Monitoring software on my laptop, but this doesn't show Active Sense in the first place and furthermore it takes data from the USB connector of the Edirol, not directly from the MIDI port.

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: Edit 2

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The problem with the MIDI Mobilizer "crashing" on a Channel Pressure event seems unrelated to the Active Sense signal. When sending a Channel Pressure event to the MIDI Mobilizer through my Kawai Q-80 sequencer, the MIDI Mobilizer "dies", even though the Q-80 does not pass on the Active Sense signal nor generate its own. Furthermore, if I play back the recorded Channel Pressure event from the Q-80 to the MIDI Mobilizer without anything else connected, the MIDI Mobilizer still stops functioning. If I set the Q-80 to NOT record Channel Pressure (but it will still pass this on when it is received), the MIDI Mobilizer crashes when the Channel Pressure is played live (and thus passed on) but not when the specific part is played back from the Q-80 (with the Channel Pressure not recorded by the Q-80).

Finally, since the Q-80 does not seem to pass on nor generate an Active Sense signal, I can not get the MIDI Mobilizer to crash when sending lots of program changes to it through the Q-80, not even from the Edirol, which does have this problem when used directly connected to the MIDI Mobilizer. Once again showing problems with Program Changes AND Active Sence and no problems with the exact same events without the Active Sense.

So at this moment I seem to be having two separate ways of crashing the MIDI Mobilizer:

1. Sending Program Changes combined with an Active Sense signal. (crashes after a few seconds)

2. Sending Channel Pressure or transport control codes. (crashes immediately)

Hope this information can add to troubleshooting this strange behavior...

Thanks for forwarding the info I found out. It is in fact "strange behavior" and at some point you were told right; the Active Sense by itself does "not interfere with the MIDI Mobilizer's ability to interface with apps", only as soon as some 1-byte MIDI events are introduced along with it (or rather in between it) something goes wrong. I'm not familiar with how exactly firmware works, but I believe it is "just" some form of software and as far as I can figure out it seems to "crash" at some point.

According to MIDI specifications the Active Sense signal should NOT be send out any longer as soon as other MIDI events are send and continue to send as soon as no other MIDI events are send out for at least 300 milliseconds. Unfortunately there is no way for me to check if the Edirol controller is behaving according to MIDI specifications, but I've been doing a lot of reading on this and many sites report that Roland is one of the few companies that is very persistent in using Active Sensing in almost all their product, so I guess by now they know what they are doing and that they are doing it right (Edirol is a Roland devision). Furthermore I think that receiving devices (like the MIDI Mobilizer) should not crash on bad data, even if it would not be 100% compliant to the MIDI specifications.

Anyway; I can now fix my personal problem by putting the Anatek MIDI Merge box I wasn't using anyway before the MIDI Mobilizer, but it would be nice if I could use both MIDI Mobilizers (I have only one MIDI Merge box) because I was planning a little project creating music with my three iOS devices all running NanoStudio. I have yet to buy a third MIDI Mobilizer, but I think I'll wait a while until the problem is solved (or just but two more MIDI Merge boxes along with it). :-)

That's great news! :-D I recently tried to "kill" the MIDI Mobilizer with my "new" GEM WX2 but couldn't. I was just about to figure out "why not" this evening, but I guess that won't be necessary any longer. I (and probably others) will anxiously await the update. Great work!