Objective Development Forums

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

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...

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...

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...

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- | ...

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 ---------------------------- */...

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

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...

Hi Alan,

any success so far?

Ciao Martin

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

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 ...

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...

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...

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

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 ...