Search found 63 matches

by horo
Thu May 21, 2009 11:29 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Re: USB MIDI Interface

Hi Dave, I've tested the timing with a program fragment like Patrick's (some posts above ^^). I checked the usb lines and the debug port pins with a scope. Pin D.7 toggles permanently with some inactivity (about 120µs) every 2 ms. So there's more than 90% of cpu activity for user program. Ciao Martin
by horo
Thu May 14, 2009 10:06 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Re: USB MIDI Interface

Hi Dave,

could you please test my recommendation:

Code: Select all

bmAttributes=3 (interrupt), bIntervall=2 
to verify that it works well on win7.

Ciao Martin

:?: Any Mac users around :?:
by horo
Tue Apr 28, 2009 3:20 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Re: USB MIDI Interface

Hi, did some "research": linux: bmAttributes=2 (bulk), bIntervall don't care -> 2ms poll, low cpu load bmAttributes=3 (interrupt), bIntervall=1..3 -> 2ms poll, low cpu load bmAttributes=3 (interrupt), bIntervall=4..7 -> 4ms poll, low cpu load bmAttributes=3 (interrupt), bIntervall=8..15 ->...
by horo
Tue Apr 28, 2009 9:56 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Re: USB MIDI Interface

... There's something i am wondering: Consumes 90% or more of the AVR's CPU time because bulk endpoints are polled aggressively by the host. Real-time applications on the AVR are close to impossible. Since we are now using bulk endpoint (are we?) is this a concern for us? ... Patrick Hi Patrick, I ...
by horo
Thu Apr 23, 2009 11:21 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

USB MIDI Interface in Bulk mode 2 ms

Hi Patrick, I've read the descriptor section in main.c again and changed some values and suddenly -tada! - my test program sends data (4 or 8 byte) every two milliseconds! Then I started again step by step - it's only necessary to change the values of bmAttributes from 3 to 2 (Interrupt -> Bulk) in ...
by horo
Wed Apr 22, 2009 10:37 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

USB MIDI Interface updated

Hi, I've just uploaded a new version of my project - it's got a new name V-USB-MIDI according to the new driver name. I made no big changes but I updated to the last version of v-usb (2009-04-15). V-USB-MIDI-0.2 hi pat, I have no idea how to speed up the communication - but maybe christian knows?? C...
by horo
Mon Mar 23, 2009 10:55 am
Forum: V-USB
Topic: 12 mhz vs 20 mhz
Replies: 2
Views: 2815

Hi pat,

yes you're right - the proc will run faster over your code.

Ciao Martin
by horo
Mon Feb 23, 2009 10:31 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Hi hs4pmh, I didn't implement midi out but pat did it - look about 5 postings ^above^. He used a piece of code from m Concerning multi midi the doc midi10.pdf (p.13) says: USB-MIDI converters can connect to multiple Embedded MIDI Jacks. Each MIDI Endpoint in a USB-MIDI converter can be connected to ...
by horo
Fri Feb 20, 2009 10:44 am
Forum: V-USB
Topic: avrusb and sleeping
Replies: 2
Views: 2850

by horo
Mon Feb 09, 2009 11:44 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Hi Patrick, just returned from holidays - now I'm trying to dig into my code. I didn't use usbFunctionRead and usbFunctionWrite - if I understand correctly you can transfer some kind of config data in bigger chunks up to 254 bytes. These threads describe the programming: m m or look at the descripti...
by horo
Wed Jan 21, 2009 9:10 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Hi pat, yes, it's possible to add an midi out, it's handled in this function. You have to add your UART_out routine and feed it with the data: /*-----------------------------------------------------------------------*/ /* usbFunctionWriteOut */ /* this Function is called if a MIDI Out message (f...
by horo
Fri Oct 31, 2008 4:55 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Hi Nuno, after some problems viewing your pics I found them - nice pice of hardware. How do you connect the 28 pots to the AVR - do you use a mux? That's what my project is intended for - letting musicians create their own midi gadgets. Do you know the pepper project? m This guy uses AVR-MIDI for dr...
by horo
Fri Oct 10, 2008 4:38 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Hi, me again I've digged in the foum and found this thread: m about bulk/interrupt and timing. Funny, usb interrupt is not really interrupt. For my understanding interrupt has something to do with a door bell rung by a visitor and the usb spec behaves like someone who opens the door every minute to ...
by horo
Thu Oct 09, 2008 6:32 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

Hi meh, the slow transfer rate comes from the usb standard. A low-speed device has no bulk transfer - it uses interrupt transfer at a rate of maximal 1000 messages/s. The midi protocol puts 1 or 2 midi commands (4 byte) into one message (8 byte) -> voilà! I hacked this project and it worked for my n...
by horo
Tue May 20, 2008 10:38 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 182133

V-USB-MIDI is online

Hi,

the first documentation and software is available at http://cryptomys.de/horo/V-USB-MIDI

Ciao Martin

EDIT 2009-04-23: new name and new URL
EDIT 2016-02-15: new name also in header ;)