Midi triggers and Pearl Expert

[Thomas1987]

Hi all,

 

Interesting project coming up. Essentially it will be a set of BMX ramps, which need pressure pads fitted which will trigger certain lighting effects to occur.

 

My immediate thought is to use midi triggers, which will trigger a certain chase/playback on our pearl expert. However, I've only seen proper midi timecoded posts relating to this on BR, rather than getting it to to accept a trigger based on velocity and random.

 

Immediate thoughts: Something along the line of "drum triggers", which would sense the vibration of the bmxer landing on a certain platform, and trigger a playback for that ramp. Am I right in thinking this is how they work? Is there a better sensor which can take a bit of abuse, and detect vibration? Ideally it would be a proper pressure sensing matt, but not had any luck finding these.

 

Would probably be at least 4 triggers on various ramps around the room. Pearl Expert is currently running classic software although we can dual boot with titan.

 

Am I on the right lines, or should I be looking at something like Chamsys for inputs?

 

Early days on this, so please feel free to slate me if I've got it utterly wrong!

 

Dave

[dbuckley]

Easiest: you need to do a bit of engineering on the ramps, so that when an additional load is added, then a microswitch is closed.

 

Its a mechanical problem - if you're not mechanical, find someone who is.

 

I'd not recommend doing audio triggers with mics, but if you want to try it, then an Alesis DM5 is the way to go. You may need a preamp or mixer in front to get mic level to what the DM5 will accept, its on jacks intended for unbalanced drum sensors, but I just plug in a feed out of an aux and it works fine. The DM5 produces MIDI note on / note off.

 

You could also use beam break detectors, or PIRs, or proximaty sensors, or ultrasound rangers, or a CCTV camera with a camera switcher with an integrated movement detector, though that might be a bit slow.

 

To convert contact sensors (sometimes called volt free contacts, or GPI contacts) then you need a GPI to MIDI, I have and can thorughly recommend the MidiTron, but a blue roomer found a cheaper alterative that looks good, a company called Highly Liquid.

 

Once you've got MIDI, the next question is have you got the right kind of MIDI? I dont know what a Pearl wants, but if what you have and what you want are not the same, then MIDI translation is recommended: Try MIDI Ox, Bome's MIDI translator, PCStage (my fave, of course), or MAX MSP.

 

PCStage can convert joystick port buttons to MIDI triggers (well, to almost anything, but thats another story) and may be an easy option with just four triggers; Joystick port (15pin D type) to USB interfaces are available widely.

 

Sounds like a fun project - keep us posted.

[niclights]

Regarding Pearl and MIDI control, Classic is better for your application at the moment. Titan currently only uses it for timecode, but Classic allows you to fire playbacks etc.

 

Details are in the manual but as an overview:

 

Program change = set playback page.

Note on = fire playback.

Velocity = playback level.

Aftertouch gives further controls on chases.

 

It is important to mention that it does not recognise note off. To turn off a playback you must send note on with velocity zero. So this might be a problem. One idea could be each ramp fires a specific chase (note number), always at full where the chase is designed to only run once rather than loop. That way you could guarantee it ended with zero intensity, assuming that's what you need.

[Thomas1987]

Regarding Pearl and MIDI control, Classic is better for your application at the moment. Titan currently only uses it for timecode, but Classic allows you to fire playbacks etc.

 

Details are in the manual but as an overview:

 

Program change = set playback page.

Note on = fire playback.

Velocity = playback level.

Aftertouch gives further controls on chases.

 

It is important to mention that it does not recognise note off. To turn off a playback you must send note on with velocity zero. So this might be a problem. One idea could be each ramp fires a specific chase (note number), always at full where the chase is designed to only run once rather than loop. That way you could guarantee it ended with zero intensity, assuming that's what you need.

 

Ah, that could be an issue - all very vague, but it would be essentially be something like as he lands on the top of a ramp, it may fire off a smoke machine and change some led bars to another colour.... so yes, an off would be needed! To be honest, Pearl programming is least of the issues!

 

dbuckley - like the idea of beam break sensors, much more realistic than expecting them to not land on any sensors!

 

It's very much early days for the project, it may well be there is only 1 BMX'er on the ramps at any one time, in which case midi triggered events would be overkilled, as it would be a rehearsed show, and could be opped. I will have a word with my colleague tomorrow who has far more experience with midi than myself, and let you know if I have any more questions!

 

Thanks for your help! I'm sure its been done before, but its certainly looking a definite custom build! (Thus why I liked the drum triggers idea!)

[dbuckley]

Connecting lighting and sound to stuff is fun

 

Any questions, come back - this is my playground....