Tempo and cue light display

[James Perrett]

Have you found the Arduino emulator? This is the one that we've installed here

https://www.sites.google.com/site/unoardusim/home

It can emulate various external hardware as well as emulating the Arduino itself.

I bought a bunch of large 10mm LED's in various colours from Ebay which seem very bright and can be driven directly from the Arduino through current limiting resistors.

[n o i s e f l e ur]

A quick websearch revealed some hits for Cantabile re: MIDI > DMX . . . perhaps a solution already exists for controlling a straightforward box of lights down that route?

Thanks, I'll take a look.

I seem to have created clean Arduino code. I now await the test hardware arriving, whereupon I can build my test rig, run my code and then consider how I'm going to put together the 'robust' working hardware version.

Ideally I'd like to scale up from tiny LEDs to something more visible - maybe use white LEDs and place each under a bit of coloured plastic? I'm useless at DIY!

Anyway, one step at a time. First to test the circuitry and my code...

Looks like you've the situation well in hand - I guess my own experiences trying to reinvent some quite complex wheels in the past tend to send me in search of pre-existing wheels these days.

Best of luck with it!

[The Elf]

Have you found the Arduino emulator? This is the one that we've installed here...

This would be a really good aid, but it doesn't have the MIDI library included and I can't see any way to add it.

I bought a bunch of large 10mm LED's in various colours from Ebay which seem very bright and can be driven directly from the Arduino through current limiting resistors.

Sounds good, but my electronics knowledge is very basic! What constitutes a 'current limiting resistor'? What resistors would I need, and where would they be placed?

Really appreciate the advice!

[James Perrett]

I just had a quick play with the sample code from the Midi library from the Arduino website and I seem to be getting error messages about paths to the library in the emulator. The sample code compiles fine in the normal Arduino software so I guess the emulator hasn't been set up to find all the library files yet (or maybe I need to update my old version of the emulator).

You need a resistor in series with the LED. I'm always a bit cautious so I'd start with something like 390 ohms which should give around 10mA through the LED with a 5 volt output. If you don't have a 390 ohm resistor to hand you could go up to 1k or even slightly higher for testing although lower values will give you a brighter LED.

[forumuser840717]

Would something like this MIDI controlled relay module be any help? I've used a few of these in very simple show control/cueing applications for theatrical stuff, just to fire basic switch commands via the relays from MIDI from a sequencer or MSC system to kit that doesn't understand MSC messages. Using them to switch cue lights on and off is very simple.

[The Elf]

I just had a quick play with the sample code from the Midi library from the Arduino website and I seem to be getting error messages about paths to the library in the emulator...

Yes, I've spent a happy afternoon looking at all the emulators out there (executables and cloud) and none seem to have the MIDI library. Still, I've used a free cloud service to run a few very basic tests of parts of my software (excluding MIDI-related code) and hardware - and it's working so far.

You need a resistor in series with the LED. I'm always a bit cautious so I'd start with something like 390 ohms...

Perfect. I did blow up a couple of virtual LEDs, so I added a few 220Ohm resistors that cured the problem - so I guess I sort of muddled my way to the answer!

Thanks so much for the help.

[The Elf]

Would something like this...

Thank you. That does look very like what I'm trying to achieve. I'll keep this bookmarked for now and see how my own solution progresses. I would still have the old problem of building a box for either solution, which is going to be the nightmare part of this for me!

[James Perrett]

Our lad says just use the hardware - "emulators are too fiddly" were his words.

[The Elf]

Our lad says just use the hardware - "emulators are too fiddly" were his words.

The cloud emulator has been very helpful in allowing me to fine-tune my code and my circuit design. I've gone from 'Hello World' to optimised multi-tasking-capable code that handles all my six lights, with variable brightness, variable flash time... and all done so I can just plug the MIDI library code in when I have it available. It's been quite a day!

[Murray B]

I always learn loads from these kind of threads as they cover a world of stuff that I am completely clueless about...

So feel free to ignore input from the clueless, but having been in a band where we had a IEM only mic for the MD who was essentially whispering in our ears what's coming next I have a few out of the box suggestions:

Can you / do you all use IEM's?

If that's the case..

Can you record vocal samples of the required instructions and then trigger them from midi to appear in the IEM's

Might be easier than an electronics project, but not so much of a voyage of discovery

[The Elf]

Thanks for the thoughts.

I'm the only one that consistently uses (and prefers) IEMs. We have experimented with audio cues, but they really don't work for all kinds of reasons.

A simple box with a few lights on really should hit the spot - and has the approval of all concerned, which is no easy thing to achieve!

I'm confident I'll be able to get this working now. What daunts me is how to box it, but I'm ignoring that voice right now.

[innerchord]

If you have the budget I'd consider the MIDI to DMX route. So much flexibility and choice there.

[James Perrett]

Our lad says just use the hardware - "emulators are too fiddly" were his words.

The cloud emulator has been very helpful in allowing me to fine-tune my code and my circuit design. I've gone from 'Hello World' to optimised multi-tasking-capable code that handles all my six lights, with variable brightness, variable flash time... and all done so I can just plug the MIDI library code in when I have it available. It's been quite a day!

Sounds like you are doing well - you'll be building all kinds of gadgets now!

[Wonks]

What daunts me is how to box it, but I'm ignoring that voice right now.

How about building it into a stage set based on Stonehenge?

[The Elf]

If you have the budget I'd consider the MIDI to DMX route. So much flexibility and choice there.

I'm sure you're right, but I've chosen a path now and I'll continue to travel it until it takes a wrong turn.

And besides, the journey is quite inspiring. If at the end of this process I have no more than a few Arduino coding skills it will have been worth it. In one day I built (virtually!) the device I need. With what I've learned I now really could turn my hand to all kinds of useful little devices.

I've nothing more to do now until the starter kit turns up.

[The Elf]

What daunts me is how to box it, but I'm ignoring that voice right now.

How about building it into a stage set based on Stonehenge?
Oh, I'm warm to that idea - very warm!!!

[The Elf]

This is what I ended up making. It works over MIDI and/or USB. I chose lit arcade buttons for their large, clear display.

This version is hard-coded to the MIDI channel and controller IDs I use, but in theory I could use the arcade buttons I've chosen to do some basic settings for channel, controller numbers, message type, or the like - probably with a display of some kind to make it friendly. For me this suffices.

Quite proud of this!

https://youtu.be/CBTiqZldzpo

[BJG145]

...oh, very nice.

[Guest]

Very neat, what is in there a Teensy?

[The Elf]

Very neat, what is in there a Teensy?

Arduino. I ordered Nanos, but I also received a couple of additional, unsolicited (brushing?), Micros before I completed the second box. Serendipitously, it turned out that the Micros are the better ones to use, since they additionally support MIDI over USB. It's on my list to take a look at the possible suitability of Teensy, since I understand I can easily give these a USB name.

The first prototype runs MIDI-only (Nano) and the subsequent ones run MIDI and USB (Micro).

Now I've upgraded the hardware to include a backlit LCD screen, with contrast control, and the software to take input from the buttons. I've set the buttons to scroll and edit a list of parameters - MIDI channel; CC/note number for each light; LED brightness factor.

The display/backlight turns on/off automatically when any button is activated and settings are stored automatically between power cycles.

So now it's user-configurable!

I'm even more proud of this project now. It's already very much in favour with the band and I've been asked to make them for other players, which validates what I've created, though this would be too onerous. Maybe if I could design and have made a dedicated circuit board and custom case (the prototype cases take ages to drill/cut and are woefully reflective of my physical DIY skills! ).

When the latest version is up and running (I'm awaiting a few parts to complete the build) I'll make a new video showing what it can now do.

This is one of those devices that is hard to explain to people, but when they see it running they get it. The next prototype is allocated to 'the other place' for artist cueing in the studio.