This was a nice challenge for the weekend: I implemented a driver for USB MIDI Host mode into MIOS32 for STM32F4
(LPC17 and STM32F103 don’t support USB Host mode…)
Tested with following devices:
CME X-Key:
Waldorf Blofeld:
MIDIbox (here MIDIbox SEQ V4L):
Ploytec GM5x5x5
USB MIDI Host mode just replaces USB MIDI Device mode via the USB OTG socket.
The update will be available with all future MIOS32 applications, it’s always available without special configuration.
A special USB Micro-B -> USB 2.0-A adapter is required to connect the MIDI device.
Pluck this adapter into the Micro-USB socket of the STM32F4-Discovery board, reset (or power-cycle) the core, and MIOS32 will automatically switch to USB Host mode.
Limitations:
USB hubs are not supported, the MIDI device has to be connected directly.
USB based Power-Supply is weak (limited to ca. 200..300 mA), which means that it might be required to power the MIDI Device with an external PSU
the MBHP_CORE_STM32F4 module has to be powered from the USB debug socket
Please let me know if you are interested to beta-test this enhancement, I could provide a preliminary version of a MIOS32 application.
I think that it will work without problems with the GM5, since the GM5 is class compliant (like the XKey). Basically, 90% of MIDI devices should work with that (the 10% remaining devices requiring proprietary USB drivers, especially the MOTU or Behringer devices…)
looks very interesting to me! normally i would volunteer as a beta-tester, but unfortunately i havent got the usb-cable (yet). but if you want, you can send me already the beta-mios32 and then i have a reason to get one. excellent work!
thanks tk, have done that! btw. even found a cable. its a usb-otg cable, which i bought for my nexus7. i think it will work with that. photo is attached…
thanks tk, have done that! btw. even found a cable. its a usb-otg cable, which i bought for my nexus7. i think it will work with that. photo is attached…
yeah! it does work with my m-audio axiom25. power from the usb-port is not enough for that, so it will need an external power supply, but yes it works. the only problem is, that you cant use the usb-port for mios-studio anymore, because, windows cant detect it as a mios32-device, but i guess this is normal…
the only problem is, that you cant use the usb-port for mios-studio anymore, because, windows cant detect it as a mios32-device, but i guess this is normal…
Yes and no.
Yes: a code upload won’t be possible, because the Bootloader doesn’t support USB Host (not enough memory available in the 16k boot section)
No: MIOS Studio contacts the core via SysEx messages, which should also be possible via a USB device which is connected to your PC/Mac via another MIDI interface.
I just tried following setup:
MBHP_CORE_STM32 USB connected to a GM5x5x5
MIDI IN1/OUT1 of the GM5x5x5 connected to MIDI OUT1/IN1 of a second GM5x5x5
the second GM5x5x5 is connected to my Mac
After a robustness update in the MIOS32 USB MIDI Host driver a Query and terminal access are possible!
ok, that seems to work! have re-compiled the bootloader-update-application. it runs in usb-host-mode and it works in the terminal via a 2nd midi-interface.
unfortunately the behringer bcr2000 is my only usb-midi-interface and it doesnt allow me to transfer sysex for the code-upload. when uploading code mios studio says: “Bootloader mode cannot be entered”. looks like i need another usb-midi-interface for that..
also i noticed that compiling with #define MIOS32_DONT_USE_USB_HOST in mios32_config.h doesnt work. the application will still be compiled for usb-host-mode.
As mentioned before, USB host mode doesn’t fit into the 16k bootloader range, there is no need to try this out - it won’t work.
Accordingly, code upload via USB host won’t work as well.
Bootloader update application != bootloader.
So: whenever you want to upload code via MIDI, you’ve to connect the STM32F4 USB port directly to your PC
Best Regards, Thorsten.
P.S.: I just have improved the MIOS32_DONT_USE_USB_HOST switch, so that it excludes parts of the STM32F4 driver - bootloader should fit into memory again (with support for USB MIDI Device mode only…)
thanks for clarification! have updated my svn and re-compiled the bootloader-update-application. gcc gives now 2 warnings in usbd_req.c, but it compiles anyway. i do need that application, because after uploading a program in usb-host-mode, i have no access with mios-studio anymore, as mentioned before. the only workaround is to re-flash the bootloader with the st-link-utility, which obviously deletes all my mios-parameters. for that i need the bootloader-update-application. im using 2xdogm-graphic-lcd on my stm32f4-board, so without that i cant see anything on my displays. but when compiling the update-application with the MIOS32_DONT_USE_USB_HOST switch it still doesnt do that. have managed to change the mios-lcd-parameters after uploading the application, so it seems to work somehow, but after a storing and reseting i cant connect to mios-studio anymore…
You can’t upload a program in USB Host mode, because the upload takes place in the bootloader!
Upload process:
MIOS Studio requests a reset, so that the bootloader will be started
Once the bootloader replied (which again can’t work in host mode), MIOS Studio starts to upload the code
Hope that this clarifies the reason why it doesn’t make much sense to continue on this topic…
While I developed the USB host mode, I always uploaded the application via USB MIDI in Device mode.
It wasn’t a big deal to:
remove the USB host cable
plug-in the USB device cable
press the black reset button so that MIOS32 reboots in device mode
press the upload button in MIOS Studio.
Of course, under MacOS I’ve the big advantage that I don’t need to restart MIOS Studio when the USB MIDI Device was temporary not available.
If you are working under Windows, it might be required to restart MIOS Studio…
Alternatively you could initiate the upload from the command line (see “mios_studio --help”) to automate this.
Or consider to develop your application without a USB Host connection, find another way to connect your MIDI device during the implementation phase, and use it only when you are not working with a computer (e.g. while making music…
finally i got it! seems like the usb works much better on MacOS than on windows (like it is with other stuffl..). but i did exactly the same as you have described. after the reset, you have to restart mios-studio on windows, which is normal, and than the mios32-device disappeared in mios-studio. as my last resort i decided to re-install the mios32-driver and now it works a treat!
i know, sometimes it can get a bit annoying to describe something, especially, if we have 2 different operating systems, but we definetely have excluded all the options to get it to run under windows. hope that will help others, who may come across the same problem and many thanks for your patience anyway…
Just discovered this topic while I thought “maybe TK can implement USB MIDI host on the new Core board” - he already has!
I’ve been looking for a way to integrate the Korg NanoKontrol with the Octatrack and other MIDI gear and didn’t want to spend 100EUR on a Kenton MIDI USB host.
Got to get that STM32F4 core now - you’ll likely get another Beta tester
I’ve released a new version of the usb_midi_2x2 and usb_midi_4x4 application which supports the USB MIDI host mode. It’s the most simple application for this purpose.
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.
