Search found 63 matches

by horo
Thu Aug 02, 2012 3:27 pm
Forum: V-USB
Topic: Problem to compile a program with V-USB library [SOLVED]
Replies: 15
Views: 16952

Re: Problem to compile a simple program with V-USB library

Hi Luca, prova.o: In function `main': prova.c:(.text+0x1a): undefined reference to `usbInit' prova.c:(.text+0x3a): undefined reference to `usbPoll' you also need the V-USB part linked to your program. The best way to do this is the use of a makefile - look into a sample V-USB project. Ciao, Martin
by horo
Thu May 31, 2012 10:07 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

Re: USB MIDI Interface

Hi, some days ago I had an email discussion with Philipp (in german) about my hardware, maybe the conclusion will be helpful so I'll give a rough translation: Q: what does the inductor do? A: it formes a lowpass together with the two capacitors to filter out noise from 5v usb. Q: what about 3.3V and...
by horo
Fri Apr 08, 2011 1:36 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

Re: USB MIDI Interface

Hi, some time ago I also did some tests with win xp and linux: http://forums.obdev.at/viewtopic.php?f=8&t=1352&start=15#p9104 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 (in...
by horo
Mon Jan 03, 2011 3:03 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

Re: USB MIDI Interface

Hi happy new year to all V-USB hackers I've just pushed my local repo to bitbucket . The latest changes I did were some experiments with the descriptors - e.g. I removed the (mandatory) dummy AudioControl desc. It's also possible to remove the Jack descriptors (sections B.4.3 and B.4.4) without prob...
by horo
Thu Oct 21, 2010 5:15 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

Re: USB MIDI Interface

Hi Adrian, nice project - your hw interface sounds clever - I will try it. Did I understand your connections correctly? - the D+ pin is connectet to the 220/330 divider, the D- pin goes through 550 to the 2k2/4k7, the 5V may be replaced by a third pin to use the UsbDeviceConnect feature? D+ 5V D- | ...
by horo
Wed Sep 22, 2010 10:48 am
Forum: V-USB
Topic: Maximum Sample Rate in V-USB Data Acquisition Projects
Replies: 7
Views: 6498

Re: Maximum Sample Rate in V-USB Data Acquisition Projects

Hi Pedram, you're welcome to ask Maybe one possible solution for your problem would be if you use the "USB-SOF-heartbeat" ticking every millisecond to trigger your analog conversion (look into usbconfig.h): ... /* ---------------------------- Hardware Config ---------------------------- */...
by horo
Mon Sep 20, 2010 9:25 am
Forum: V-USB
Topic: Maximum Sample Rate in V-USB Data Acquisition Projects
Replies: 7
Views: 6498

Re: Maximum Sample Rate in V-USB Data Acquisition Projects

Hi,

Grendel is right - 10ms poll rate is the theory - but for practical tests (win: 8ms, linux: 2 ms) look at the v-usb-midi thread. And you're able to send 8 bytes packages with 4 unpacked samples (i.e. 400 samples/s).

Ciao Martin
by horo
Mon Aug 30, 2010 3:42 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

USB MIDI Interface

Hi, beside the already known Pepper-MIDI (Control SX-150 Synth via MIDI) I just discovered some fine new projects based on V-USB-MIDI: Wojciech Zabolotny's MIDI Expression Pedal and MIDI Drum Trigger and Yoshitaka Kuwata's Monaka , a MIDI/OSC hard- and software toolbox. I'm just transfering my own V...
by horo
Tue May 25, 2010 10:26 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

Re: USB MIDI Interface

Hi Alan,

any success so far?

Ciao Martin
by horo
Wed Jan 06, 2010 11:21 am
Forum: V-USB
Topic: How do you enable INTERRUPT transfers?
Replies: 5
Views: 7272

Re: How do you enable INTERRUPT transfers?

Hi,

take a look at my project V-USB-MIDI. I created a custom config and modified the endpoint descriptor to use bulk or int transfers at different poll rates:
viewtopic.php?f=8&t=1352&start=15#p9034

Ciao Martin
by horo
Wed Dec 23, 2009 11:03 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

Re: USB MIDI Interface

hmmm, if i'm correct, this way i can send at most 4 bytes at once right ? and i have no way to getting back return informations. Hi solata10, no, you can send eight bytes, i.e. two midi messages - if you set up some kind of state machine in your device you'll be able to send back a midi event as a ...
by horo
Thu Sep 24, 2009 2:51 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

Re: USB MIDI Interface

Hi K-Duke, welcome, nice that you build a drum device, good link to the hardware interfacing. I know it's frustrating if a new project doesn't work as expected. Don't worry. Well, let me try to bring some light into the darkness 1. The suspicious "sendEmptyFrame" originates from the AVR-CD...
by horo
Wed Jul 15, 2009 9:31 am
Forum: V-USB
Topic: nanoseconds
Replies: 12
Views: 7694

Re: nanoseconds

FROM avr-libc manual: void _delay_us ( double __us ) Perform a delay of __us microseconds, using _delay_loop_1(). void _delay_loop_1 ( uint8_t __count ) Delay loop using an 8-bit counter __count, so up to 256 iterations are possible. (The value 256 would have to be passed as 0.) The loop executes th...
by horo
Mon Jun 22, 2009 4:13 pm
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

Re: USB MIDI Interface

Hi muntablues,

back at my hardware I've checked again, at receive of midi signals from pc my test led at PORT C.5 toggles (in usbFunctionWriteOut). I'm running this test on a debian linux with kernel 2.6.29.4-rt16.

Ciao Martin
by horo
Sat May 30, 2009 11:38 am
Forum: V-USB
Topic: USB MIDI Interface
Replies: 93
Views: 237303

Re: USB MIDI Interface

Hi muntablues, how do you send data to the device? I connected it as an midi out and sent midi notes from my vkeybd (virtual midi keyboard application). I also connected the output from V-USB-MIDI to its input and got the leds blinking at the turn op the pots. I tested at my linux box, running jack ...