ltc & midi interface

[Guest ignamato]

Hi,

I want to use the com port interface and the standard midi interface. I´ve read that I can´t do it at the same time. so my question is: can I add a switch to change between this interfaces taking pic pins 25,26 to the switch? Is it a problem if I change the interface while the controller is turned on?

thanks :P

[TK.]

Hi,

this should work - also during the PIC is running - but you have to add an additional pull-up resistor between the Rx pin and +5V in order to avoid random MIDI events during the switch phase.

Best Regards, Thorsten.

P.S.: the switch is only required for the Rx pin to change between the optocoupler and RS232 signal

[Scuzzle]

Hmm,

Won't this cause baud rate problems?

Being that Midi and Serial use different rates?

[Guest ignamato]

thanks, another question, what kind of resistor should I use?

[TK.]

Hi,

Scuzzle: of course, you've to take care that the correct baudrate is selected (it's a special menu entry in MB64/MB64E/MBMF). But there isn't a problem so long as the cables are not connected to the port which runs with the wrong baudrate.

Pull-Up: two solutions:

1) cut the track between the Rx pin and R6. Use a resistor value which is much greater than R6, let's say 100k. Then it won't affect the optocoupler output signal

or:

2) Don't cut the track directly at the Rx pin, but between IC2/Pin 6 and R6, so that you don't need an additional pull-up resistor.

Since I would prefer method 2, here more details:

Rx Pin: connected with R6 and the switch output

IC2, Pin 6: connected with one switch input

J11:MI: connected with the other switch input

Once you get this running, please draw a schematic, add some comments and publish it at the MIDIbox Portal, since it could also be interesting for other people.

Best Regards, Thorsten.

[Guest ignamato]

ok, I have another question, can I change midi interface to serial interface without a display???

[TK.]

You could add some lines of code into the application which switches between the baudrates. I can tell you more details once I know which application you are planning to build exactly ;-)

Best Regards, Thorsten.

[Guest ignamato]

MIDIbox 64 with PIC16F877. I´ve also planned to put 16 leds (one for each button) for mute and solo. Is this possible, does it work properly using it with Cubase, reason, sonar, etc...