usb<->midi interface and midibox question

[nebulus]

I am planning to use midi<->usb interface www.edw.com.pl/index.php?module=ContentExpress&file=index&func=display&ceid=126 (it's in polish, but still easy to grasp main idea) with my midibox. Do i have to use 6N138 chip in midibox core or in usb-midi interface? Or is it enougth to connext RXD of PIC to TXD of FT232BM (and vice versa)?

Thanks in advance for your replies  :)

[TK.]

It depends on what you are planning to do with the MIDIbox.

In general you can crosslink the Rx/Tx lines, since they are working at TTL level - it works exactly like described at the MBHP_USB page (MIDIbox Link port)

But if you are using a MIDIbox which generates audio, like MIDIbox SID or MIDIbox FM, don't ommit the optocoupler - I tested this on my own MBSID and noticed some additional background noise

Best Regards, Thorsten.

[*jOi~]

On my midibox, I've tried using the FT232 as well. I originally had been using the to-COM interface, but wanted to run on newer computers with a self-powered device.

I found hooking the Rx and Tx directly from the PIC into the USB chip worked fine, although I could not find a driver to accept the MB as a midi device. I was using Yamaha CBX driver with serial cable, but when selecting COM3 (the virtual serial port for FT232) it wouldnt be recognised.

I use MAX/MSP for most MIDI tasks though, and using the serial object I could still receive all data from the port, and then unpack it into osc (but MIDI would be just as easy).

If you have any questions about doing it that way, please ask.

[Billmac]

There is an adapter by M-AUDIO which provides a USB to MIDI interface.  It is a cable with the adapter module built into the cable and powered by the USB port itself.  It works very well and costs less than 50 dollars US, including shipping.  You can find it many places on the Internet.  It solved my problem of interfacing my laptop to the core units.

Bill McKeown

[*jOi~]

billmac:

why would you spend $50 when you can slave away over a super tiny SMD chip, trying to solder each tiny pin to a wire because you're too cheap to pay for a PCB!! ::)haha

seriously though, if we can get it working, the options of direct serial transmission of the midi data mean things like baud rates of 115000kbps (~4x faster) and up to 500mA direct filtered bus power!

anywho... i will continue to try and get everything to talk to each other.