goyousalukis Posted November 24, 2002 Report Share Posted November 24, 2002 Hello, I hope someone can help me. I have built the midibox 16, and it works great - except for one thing: when I use it between my software analog sequencer emulator and my synth module, I often get hanging notes, as if the noteoff midi message got deleted. This happens when I make rapid movements on two of the sliders I use - specifically for the filter resonance and frequency. Is there a fix for this? Is there anything I can check? Thanks for any help...Justin Quote Link to comment Share on other sites More sharing options...
TK. Posted November 25, 2002 Report Share Posted November 25, 2002 Hi Justin,unfortunately this is a known problem with MIDIbox Plus. The root cause is the 4-bit LCD interface without read signal. Since the MBPlus firmware is not able to ask the LCD if a character has been printed out or not, it has to wait for a certain time before continuing with the main program. If a lot of MIDI events are received continuously, the LCD delay routine will be interrupted very often and therefore takes much longer than expected, as a result the whole display update takes more than 300 uS and this can cause a MIDI buffer overflow on a back-to-back MIDI event stream.This issue has been fixed on all MBHP designs by accessing the LCD over a 8-bit interface and by polling the busy flag of the LCD.For MPlus two workarounds are possible: if you don't use a display, I could give you a special version which doesn't try to access the LCD.If you own a LCD, I've to include some code which is also used by the MB1664 variant. This variant would require a hardware modification (read-line has to be connected with the PIC)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
goyousalukis Posted November 25, 2002 Author Report Share Posted November 25, 2002 Thorsten, thanks for the reply. I plan on building a full blown MB64 in January, so I guess I will just wait until then. Your project is great! Thanks...Justin Quote Link to comment Share on other sites More sharing options...
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