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MIDI Controller - BS2 — Parallax Forums

MIDI Controller - BS2

PRPROG01PRPROG01 Posts: 28
edited 2014-12-09 17:26 in BASIC Stamp
Using an old (2003) Parallax Midi documents (Gettin' MIDI With It - Jon Williams) I setup a MIDI out circuit on my BS2. I check the results using a PC midi interface and program call MIDI-OX (midi monitor). Results are good. I can press a button and play a Midi note on the PC synth. But (here is my dilema) when I connect the same Stamp to an external Midi module it does nothing. ?????. I have test the Midi Module with a Midi Keyboard and it works. Any ideas why the same cicuit/code work in one instance and not in the other?

Already test wirh a 9v cell and a Wallwart adapter, I though the external Midi module will need more current...no difference.

Thanks,
PRPROG

Comments

  • JonnyMacJonnyMac Posts: 9,157
    edited 2014-12-04 06:58
    It's been ages since I wrote and tested that, but I did use an external MIDI keyboard (I still have it). I can't account for the issue you're seeing. What is your target device. Do you have docs for it?

    Yes, I am the artist formerly known as Jon Williams.
  • PRPROG01PRPROG01 Posts: 28
    edited 2014-12-04 12:36
    Wow...Thanks for answering my thread. I am honor. The module is a Yamaha TX81Z . No, I dont have any documentation for it. What is weird is that the MIDI output works on the PC Synth + MIDI OX, but not on the module. I also try other Roland module but it does not work either. I also try to play both modules with a MIDI keyboard and they work OK. Therefore I dont have any idea why the Stamp does not work with the external modules.
  • davejamesdavejames Posts: 4,047
    edited 2014-12-04 13:08
    PRPROG01 wrote: »
    The module is a Yamaha TX81Z . No, I dont have any documentation for it.

    PRPROG01,

    Try these links:

    http://www2.yamaha.co.jp/manual/pdf/emi/english/synth/TX81ZE.pdf

    http://the-all.org/tx81z/
  • JonnyMacJonnyMac Posts: 9,157
    edited 2014-12-04 13:40
    I wonder... did you use a different value for the current limiters? They should be 220.

    You might also try tweaking the baud rate setting used.

    Long term, I suggest a switch to the Propeller -- it runs faster, can generate serial data in the background, and the baud generation is more accurate, too.
  • PRPROG01PRPROG01 Posts: 28
    edited 2014-12-04 17:23
    Thanks a lot for the links. Second one is just great!!!
  • PRPROG01PRPROG01 Posts: 28
    edited 2014-12-04 17:26
    JonnyMac wrote: »
    I wonder... did you use a different value for the current limiters? They should be 220.

    You might also try tweaking the baud rate setting used.

    Long term, I suggest a switch to the Propeller -- it runs faster, can generate serial data in the background, and the baud generation is more accurate, too.

    Yes I used 220 ohms resistors on the midi out connector. For the BS2 I am using MidiBaud CON $8000 + 12 . Which other baud rate can I try?
  • davejamesdavejames Posts: 4,047
    edited 2014-12-04 19:51
    PRPROG01 wrote: »
    Thanks a lot for the links. Second one is just great!!!

    Welcome! Happy to help.

    The "the-all.org" link even has the service manual about midway down the page. :thumb:
  • JonnyMacJonnyMac Posts: 9,157
    edited 2014-12-04 21:10
    The 12 is the for the baud generator; try with 11 and 13 to see if that makes a difference.
    PRPROG01 wrote: »
    Yes I used 220 ohms resistors on the midi out connector. For the BS2 I am using MidiBaud CON $8000 + 12 . Which other baud rate can I try?
  • PRPROG01PRPROG01 Posts: 28
    edited 2014-12-05 05:16
    JonnyMac wrote: »
    The 12 is the for the baud generator; try with 11 and 13 to see if that makes a difference.

    Ok. I will give it a try.
    Thanks.
  • PRPROG01PRPROG01 Posts: 28
    edited 2014-12-07 15:24
    OK. I try the changes to the baud rate. It did not resolved the issue. I found a web article that suggest that the 220 omhs resistor is only needed on the 5 volts connection to the MIDI Out connector pin 4. Well now it works only on a Casio keyboard (Previa PX-100) ....still it does not work on the Yamaha TX81Z (or a Roland U-220) .

    I activate a capability on the MIDI-OX PC program to route the MIDI IN to the MIDI OUT of the M-Audio (Midi) interface. I connect the Midi out to the MIDI in to one of my modules. Now the Stamp can send the midi messages correctly to any MIDI device . It works with the Yamaha TX81Z or the Roland U-220 . Of course this is not how I need the Stamp to work as a MIDI controller. It must work without the PC.

    It got to be the MIDI circuit, but what could it be? Any suggestions? (already using the Stamp with a Wallwart adapter.

    Thanks,
    PRPROG
  • JonnyMacJonnyMac Posts: 9,157
    edited 2014-12-07 15:55
    Is it possible you have dicey connection in your MIDI connector? You might what to check the solder joints.
  • PRPROG01PRPROG01 Posts: 28
    edited 2014-12-08 03:42
    JonnyMac wrote: »
    Is it possible you have dicey connection in your MIDI connector? You might what to check the solder joints.

    First of all, thanks a lot to JonnyMac and davejames for taking the time to answer my post. JonnyMac you got the answer on post#5. One of the resistor was not 220 ohms ...it was 2200.When I took one of the resistor , the one 220 ohms, the circuit starts working only with the Casio keyboard (which means Casio is not that strict on the Midi electrical requirement) . Yesterday I notice the error, set both resistors to 220 ohms and it works like a charm on all my Midi devices (Yamaha, Roland, Casio). Sorry for not noticing this before.
  • JonnyMacJonnyMac Posts: 9,157
    edited 2014-12-08 08:39
    I rule! :)

    Very glad you got that sorted; sometimes it's tricky to differentiate color bands on resistors. It seems like every time I pop into All Electronics I pick up another hand-held magnifying glass just so I can verify things.

    Have fun with with project.
  • davejamesdavejames Posts: 4,047
    edited 2014-12-08 08:58
    PRPROG01 wrote: »
    First of all, thanks a lot to JonnyMac and davejames for taking the time to answer my post.

    You're very welcome.

    Thank you for posting the resolve. It's always nice to know "what happened".
  • PublisonPublison Posts: 12,366
    edited 2014-12-08 09:14
    Glad you got it sorted out. I was just building up the interface from the N&V article to help along.

    We all know that Jon does not put out software that does not work.:)

    I get resistors mixed up all the time, after 40 years.

    Next weekend, send some stuff to my Roland G-1000 and Kurzweil K2VX.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2014-12-08 10:23
    JonnyMac wrote: »
    It seems like every time I pop into All Electronics

    So you're the guy who buys up all the good stuff before I can get there!
  • JonnyMacJonnyMac Posts: 9,157
    edited 2014-12-08 11:16
    So you're the guy who buys up all the good stuff before I can get there!

    I live just 15 minutes away (by car), so there's no reason for me not to pop in frequently. What I really appreciate about those guys is that they're open on Sundays -- I have made many "emergency" runs over there when I needed parts on a weekend.
  • JonnyMacJonnyMac Posts: 9,157
    edited 2014-12-08 11:18
    We all know that Jon does not put out software that does not work.

    That's kind, but I am human and have slipped once or twice. The MIDI stuff was old, but I had run it through an external keyboard. I recently made a small MIDI adapter board for a friend to use with Propeller projects. It's the same circuit with a couple small gates to bump the 3.3V to 5V.
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-12-09 17:26
    JonnyMac wrote: »
    magnifying glass just so I can verify things.
    These work GREAT for that and reading those tiny letters on IC's, etc.!!!

    http://www.ebay.com/itm/USB-Digital-Pen-Video-Microscope-Endoscope-Magnifier-Otoscope-Webcam-tool-Camera-/200900528519?pt=LH_DefaultDomain_0&hash=item2ec69ac987
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