Midibox: too complex for my needs?

[marcvangend]

Hi,

I'm quite new to midi electronics, especially to making it myself. I hop you can help me decide if I should go ahead and build something myself...

I have a Yamaha BBT 500H all-digital bass amplifier. (more info: http://www2.yamaha.co.jp/manual/pdf/emi/english/gtamp/bbt500h_en.pdf) It's got 5 programmable presets which I would like to select using a floorboard. Unfortunately, there is no regular footswitch available, but the amp does have midi-in for this purpose. What I would like is quite simple: a floorboard with 5 buttons (one for each preset) and maybe 5 leds (indicating the chosen preset).

I am sure this can be done with a MIDIbox64, but seeing the countless possibilities, I wonder if this might be 'overkill' for such a simple floorboard. Even after reading a walkthroughs ans FAQ's, I cannot really oversee how much work it would be to realize this. It is also hard for me to estimate how much it would cost to build a floorboard like that.

Browsing the internet, I came across two other options for my needs:

- building something myself, based on the Pocket Electronics component from Döpfer (http://www.doepfer.de/pe.htm) - €80 + case & controllers

- buying a rocktron Midi Xchange (www.rocktron.com), a 3-knob 'smart controller' - €90

I hope your reactions will help me make a sensible decision between cost, function and the amount of energy I'll have to put into it. Thanks!

[stryd_one]

Gday mate, welcome to the board!

If you only need 5 switches and 5 LED's, you will only require a core module, no DIN and DOUTs. You might want an LCD there for debugging purposes but you probably wouldn't need it permanently.

I hope this helps

stryd_one

[Wisefire]

what application would he have to use?

[illogik]

are you sure stryd? i think you can save either a din or a dout by using J5 either as in- or as output.

overkill doesnt exist here; a core module will cost around 20 euros an can be programmed as basic as possible

forget the other options, your box will be quite easy to make; i guess it will cost you about 40 euros without the case, knobs and psu

good luck, marcel

what application would he have to use?

mb64, like i said you can keep all the projects as basic as possible, a mb64 with just 4 knobs is one of the many possibilities;

when choosing a project; just look for the one that can do what you want you can leave out everything you dont need

[marcvangend]

Hi everyone, thanks for helping me on this one.

If you only need 5 switches and 5 LED's, you will only require a core module, no DIN and DOUTs. You might want an LCD there for debugging purposes but you probably wouldn't need it permanently.

So, that would be even simpler than the low-cost version below, mentioned in the wiki (http://www.ucapps.de/mbhp/mbhp_midibox64_lc.gif):

Sounds good, but as illogik points out: where would you connect the buttons and leds?

[stryd_one]

You could alter the application to use pins not really designed for that use, but that might make things a bit difficult... I probably shouldn't have suggested it, sorry!

I would recommend using J5 for the switches (J5 as DIN) and one of the four parts of a DOUTx4 module. This will give you up to eight switches and eight LEDs, but with easy upgrade path to more LED's which might be handy in the future.

This post might be useful, as well as the J5 as DIN/DOUT examples on the downloads page at ucapps.de:

http://www.midibox.org/forum/index.php?topic=5898.0

Using that concept, you could have preset up and preset down pedals to scroll through the 5 presets, and have 5 LED's (or maybe even a seven-segment LED digit display?) to show which preset is in use... But the easier way if you're not too familiar with the programming would be as above with a single DOUT module for the LEDs.

[th0mas]

Pretty much all the pins on the PIC are programmable to be Inputs or Outputs.  He could do the entire thing using the CORE LCD port, which is PORTB on the PIC.  The pins can be configured to be inputs or outputs, and it's easy as pie to send midi commands.

marcvangend:

All you'd need is one CORE module and a power supply for it.  Do you know basic C programming?  If so, you could do this yourself.  If not, I could write this app for you once you have a CORE module working.  It's really easy to do, I could do it in quickly if you told me the MIDI commands you need to send to the amp.

Cheers,

Tom

[stryd_one]

Pretty much all the pins on the PIC are programmable to be Inputs or Outputs.

Sorry, when I say "not designed for" I mean that in the context of a standard MBHP/MIOS configuration.

I thought that doing this might be too complex but as you say, done it C, it would be very easy - just mixing a few of the example apps would have it 90% done.

[nebula]

You still need a rugged momentary pushbutton switch suitable for foot operation.  It might be tricky to find something for a good price. 

You probably also want a nice low-profile, wide enclosure about the size of a computer keyboard, but not plastic.  You could go a long way with a home-brew enclosure made with plywood and a sheet of metal.

Since you're going the DIY route, I would consider mounting the core, DIN, DOUT electronics into the amp and run a single multi-conductor cable to an otherwise "dumb" pedalboard - this would reduce cable clutter and give you the added advantage of probably being able to draw from the amp's power supply.

BTW while Doepfer's option excluding case & controllers is 90 euro, SmashTV's price for a complete core, DIN and DOUT kit is US $48.95.

[th0mas]

BTW while Doepfer's option excluding case & controllers is 90 euro, SmashTV's price for a complete core, DIN and DOUT kit is US $48.95.

He wouldn't need a DIN or a DOUT, just a CORE.  Think about it, max he needs is like, 8 I/O pins.

[marcvangend]

Thomas,

Thanks for offering to program the app in C. I have no skills in C at all, I wouldn't even know what software you use to write it in... I'll know where to find you once I've decided on what I want.

He wouldn't need a DIN or a DOUT, just a CORE.  Think about it, max he needs is like, 8 I/O pins.

I don't quite understand what you're saying here. Maybe I'm thinking too simple, but if I want 5 buttons and 5 leds, wouldn't I need 10 I/O pins?

[th0mas]

Sorry I hadn't paid attention.  Yes you'll need 10 I/O pins.  The PIC itself has more than enough pins to cover you, so all you need is one CORE kit from SmashTV (or wherever).  From there I can provide the application and tell you what connections to use.  Let me know when you have the gear set up.

Cheers,

Tom

[stryd_one]

Something that shouldn't be forgotten here is the big mistake a lot of DIY audio/MIDI newbies don't realise they're making... OK sure Smash's kit is 1/2 the price... Now add on all the tools you need.... DIY is NOT the cheap option....at least, not until after at least your third of fourth project.

Check it: http://www.midibox.org/dokuwiki/doku.php?id=stryd_one_preparation#hardware

This is a pretty comprehensive list, and some of these things can be done without. But some can't. I'd say even the most basic toolkit will push you over the cost of a commercial device.

[DrBunsen]

stryd_one: excellent list.

What about the old floorboard project?  Only needs a PIC 16F and you could probably make it up on vector- or proto-board, as there's no PCB available from Smash.

[marcvangend]

Thanks to all of you for the input.

Nebula, I like the idea of creating a dumb pedalboard and keeping the electronics close to the amp. I guess there won't be enough space inside the amp, because it's a pretty compact design:

However, I am still wondering what kind of cable/connectors would be the best option for this solution. Would a shielded 10-conductor cable suffice for 5 buttons + 5 leds? I'd like to be able to detatch the pedalboard from the 'core box'. Which connector would you use?

I understand DIY might not necissarily be the cheapest option (although I own most tools already) but I am certain that is is the best way to get a footswitch exactly the way I want it. All the reading and thinking over the past few days made me decide to take the sensible approach: I will make sure I have plenty of time on my hands before I really get started. I have to resist the temptation to start right away...

Th0mas, thanks for offering your assistance, I am sure I will need it once I get started.