BlueXav

Thank Thorsten ! I'm honoured ! The Discovery Board is already equipped with a MOSFET "power switch" (not a charge pump because it is not needed) controlled by PC0. The STMPS2141 is spec'd at 500mA max current. But as you mentioned before the voltage is a bit weak (4.3V) because of a BAT60 diode on the path. An external true 5V power connected on the 5V pin of connector P2 will avoid that drop voltage. But I suppose you already know this...

Oh great great great ! It works now ! Thank you Thorsten ! It was just the cable problem... (I have the stand alone Discovery board) I was just on the point of giving up ! So, with OTG mode can't you switch on the USB Vbus ? There is a pin (PC0) called OTG_FS_PowerSwitchOn for this. I've also made a simple MIDI out port but that remained quiet with the no power issue. I was also confused about the UART0 / UART1 namings : UART0 out <-> PA2 (USART2) UART1 out <-> PD8 (USART3) Anyway it works with the NanoKontrol V1 and Roland UM-2G. When I'll have time I'll try to transpose my Dekrispator on MIOS32... Thank you for that excellent and monumental MIOS32 ! Xavier

Thank you very much for your answer. The strange thing is that the midi device is not even powered by the STM32F4 board. It's like the host mode was not enabled here, maybe a configuration problem ? I have not a MIDI_IO board for debugging on another port... Xavier

Hello Thorsten ! I'm very happy you made that USB host midi driver ! I've tried to write one which is roughly working and that I use in my Dekrispator machine (http://youtu.be/fcLrcDCaI7w)...but I have some disconnection problems. At the moment I'm a newbie with your MIOS32 concept, however I've managed to compile MIOS Studio on my Debian 7.4 Linux PC and compiled your usb_midi_2x2 (SVN) with Eclipse Kepler and the GNU ARM tool chain. But no luck, I can't make my stand-alone Discovery board work in Host mode : neither with Korg Nanokontrol (v1) nor Roland UM-2G. I've uploaded on the board my compiled application and your binary too (v1.10). The green vbus led (led7) flashes once and remains off. It works in device mode when connected to the PC as I see in MIOS studio. Any idea ? Sincerely, Xavier