Shop OBEX P1 Docs P2 Docs Learn Events
Is there a Stamp available that can receive serial input via midi? — Parallax Forums

Is there a Stamp available that can receive serial input via midi?

TonyATonyA Posts: 226
edited 2005-11-30 17:19 in BASIC Stamp
Hi,

I know the BS2 isn't fast enough to receive midi input, I was wondering though if it can be done with any of the other stamps.

Thank you,
Tony

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-11-28 15:17
    Tony,

    ·· This could easily be done with an SX.· In fact I'm pretty sure that a MIDI project has been done with the SX.· I will see if I can dig it up and post a link for you.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-11-28 15:21
    Whoops!· A second look shows you have already created a MIDI controller in the Projects Forum.· It's not clear what you used to do this, however.


    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Tom WalkerTom Walker Posts: 509
    edited 2005-11-28 15:34
    Let's be accurate. The BS2 is plenty fast enough to receive MIDI input. The fact that it is single-tasking would probably limit what you can DO with the data while trying to "keep up with the stream"...

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Truly Understand the Fundamentals and the Path will be so much easier...
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-11-28 15:38
    Yes Tom, the BS2 can receive data at the MIDI baud rate.· The problem would be sustained data throughput.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Clock LoopClock Loop Posts: 2,069
    edited 2005-11-28 16:00
    Would this apply to ANY BS2? Even the BS2PX ???
  • Tom WalkerTom Walker Posts: 509
    edited 2005-11-28 16:06
    Since the px is faster than the stock BS2, it is even more capable, but still probably not fast enough to accomplish much between MIDI events...depending on the speed of the events, your quantization and other MIDI stuff [noparse]:)[/noparse]...

    As was previously stated, the SX would probably be a good choice.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Truly Understand the Fundamentals and the Path will be so much easier...
  • TonyATonyA Posts: 226
    edited 2005-11-28 16:27
    Chris,

    yeah, I have made midi controllers that just send midi out, now I'm trying to make a midi receiver. BS2 works great at sending midi, now wondering which stamp I can use to receive/process midi input.

    Thanks for the help, I appreciate it.

    Tony
  • Tracy AllenTracy Allen Posts: 6,664
    edited 2005-11-28 16:30
    Craig Sapp used a MAX3110 to buffer a MIDI input stream to a BS2sx:

    devices.sapp.org/micro/stamp2sx/max3110/

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Tracy Allen
    www.emesystems.com
  • TonyATonyA Posts: 226
    edited 2005-11-28 17:06
    Hi,

    I just read Sapp's info on the bs2sx midi in/ out. He says that it really isn't fast enough but will do the job if the midi data is not "dense".

    "The rate for MIDI is 31.25k which is faster than the transfer rate between the MAX3110 UART chip and the BS2SX, so you cannot use this setup for dense MIDI data transfers." (Sapp)

    Would this cause a big problem?

    Thanks again,
    Tony
  • metron9metron9 Posts: 1,100
    edited 2005-11-28 18:45
    Somebody said...

    yeah, I have made midi controllers that just send midi out,


    Could you post a link to information on making a midi out controller as far as the logic and communication and pinout of the receiveing midi controller. I can do the circuit input to the microcontroller but I dont know yet how to communicate with the midi receiver.

    I use midiman inputs and GigaStudio as well as garrisons Orchastra and kandaki. I have a new acoustic drum set and I am thinking of putting the piezo tabs on the drums to add effects through a midi interface. I am at work now and I did a search on projects but only found 1 thread so far.


    Arggg gotta go bact to work...

    Thank's

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Think outside the BOX!
  • TonyATonyA Posts: 226
    edited 2005-11-28 18:54
    Hi,

    There's a lot of info on the web to do just what you describe, using piezo, etc. Also, Jon Williams has done some work with midi and the BS2. (His examples got me started). There is an article called "gettng midi with it" and "mo midi" in the "nuts and volts" archives of this site. It's very easy to do, once you see the examples and articles you'll have no problem.

    Tony
  • Tracy AllenTracy Allen Posts: 6,664
    edited 2005-11-28 20:00
    TonyA said...
    so you cannot use this setup for dense MIDI data transfers." (Sapp)

    Would this cause a big problem?

    Thanks again,
    Tony

    I guess it depends on what you are doing. If the only data coming in to the STAMP MIDI gizmo are keydown and keyup events from one instrument, it could work. Unless somebody bangs on the keys with unheard of speed! The MAX3100 buffers up to 8 bytes, and each keydown/keyup event is 3 bytes long.

    It is another matter if the Stamp MIDI will be a hub or if it will have to receive "dense" information like timing sync (24 bytes per quarter note) or dense percussion events.

    There was a question about the BS2px. It does SHIFTIN and SHIFTOUT at 65 kbits per second. But it has to transfer 16 bits for each serial byte. So its transfer rate per byte is roughly the same as the MIDI rate. That is somewhat faster than the BS2sx. But the 'px can do a lot lot more instructions per unit time, compared to any other Stamp.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Tracy Allen
    www.emesystems.com
  • TonyATonyA Posts: 226
    edited 2005-11-28 20:21
    I see. I would only be using it for receiving note on/note off messages. I have to give it a try. Thanks again for the great help.

    Tony
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-11-29 01:22
    You can apply your PBASIC skills to the SX with SX/B -- here's a MIDI project I did: http://forums.parallax.com/showthread.php?p=533525

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Jon Williams
    Applications Engineer, Parallax
  • TonyATonyA Posts: 226
    edited 2005-11-29 19:26
    Hi Jon,

    Very cool, thanks for that info. I will be looking into this.

    Tony
  • metron9metron9 Posts: 1,100
    edited 2005-11-30 15:01
    Thanks for the link it is easy. Now where can I get a comprehensive list of midi command codes, the dry reading type stuff. No success yet googeling a list.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Think outside the BOX!
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-11-30 16:30
    The only way to get·a truly comprehensive list is to purchase the MIDI specification from MIDI.org.· And I guess your Google button is broken tongue.gif because I've found dozens of web sites that are helpful, some more than others of course.· Here's a particial list to get you going:

    http://www.gweep.net/~prefect/eng/reference/protocol/midispec.html
    http://www.midi.org/about-midi/table2.shtml
    http://users.chariot.net.au/~gmarts/midimsg.htm
    http://nosuch.com/mostly-midi/archive/midiintro
    http://www.cs.cf.ac.uk/Dave/Multimedia/node158.html
    http://www.omega-art.com/midi/mbytes.html
    http://www.sibelius.com/helpcenter/resources/midi_messages.pdf
    http://www.harmony-central.com/MIDI/Doc/table1.html

    That should get you going.


    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Jon Williams
    Applications Engineer, Parallax
  • metron9metron9 Posts: 1,100
    edited 2005-11-30 17:19
    Thank's very much Jon, The book is on order and the tables of commands I was looking for are in the pages of the great links you have provided.

    As my dad use to say, "Do it right or don't do it at all"

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Think outside the BOX!
Sign In or Register to comment.