Marxon Posted February 12, 2014 Report Share Posted February 12, 2014 Hi all! I like to control my Seq V4 (LPC1769) with my MidiboxNG (STM32F4) via Midi. Is it correct if i connect LPC1769 Core P2.1 to STM32F4 Core PA2 and LPC1769 Core P2.0 to STM32F4 Core PA3? Thanks for your advice. Marxon Quote Link to comment Share on other sites More sharing options...
mono Posted February 12, 2014 Report Share Posted February 12, 2014 (edited) ...it is correct, if you want to connect MIDI-Port1 (LPC) to MIDI-Port1 (STM32F4), so you should be able to receive midi with your lpc from the stm32 and receive with your stm32 from the lpc... mOnO Edited February 12, 2014 by mono Quote Link to comment Share on other sites More sharing options...
Marxon Posted February 13, 2014 Author Report Share Posted February 13, 2014 Ok. Thanks for your reply mOnO! Quote Link to comment Share on other sites More sharing options...
TK. Posted February 18, 2014 Report Share Posted February 18, 2014 Since STM32F4 outputs the MIDI Tx signals in open drain mode, it makes sense to add a 1k pull-up resistor to this pin. Not relevant for the Tx output of LPC17, since there it's configured in push-pull mode (due to a hardware imperfection) Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Marxon Posted May 17, 2014 Author Report Share Posted May 17, 2014 (edited) Hi again! I have another question about the STM32F4 midi in/out: How do i connect external midi devices? Can I use this circuit? Best regards Marxon Edited May 17, 2014 by Marxon Quote Link to comment Share on other sites More sharing options...
ilmenator Posted May 17, 2014 Report Share Posted May 17, 2014 Yes - I am not sure about the pin names (haven't checked them), but the schematic is the standard MIDI schematic to be used! Quote Link to comment Share on other sites More sharing options...
Marxon Posted May 17, 2014 Author Report Share Posted May 17, 2014 Ok thank you ilmenator! Does it make a difference if i connect the optocuppler Pin 6 to 5V instead of 3,3V and if i use a 5,6k instead of a 4,7k resistor like in older schematics? Quote Link to comment Share on other sites More sharing options...
ilmenator Posted May 17, 2014 Report Share Posted May 17, 2014 The resistors' values depend on the voltage you apply to the optocoupler. The voltage usually depends on the microcontroller you use. However, the inputs in the MCUs used by MIDIbox should all tolerate 5V. Quote Link to comment Share on other sites More sharing options...
Marxon Posted May 17, 2014 Author Report Share Posted May 17, 2014 OK i might have known it... :blush: Thanks for clarification. Quote Link to comment Share on other sites More sharing options...
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