Objective Development Forums

Hi, Please have a look at the MIDI thread, esp. https://forums.obdev.at/viewtopic.php?f=8&t=1352&start=15#p9413 The code fragment mentioned is: for (;;) { PORTD ^= 0x80; wdt_reset(); usbPoll(); usbSetInterrupt(midiMsg, 8); } When you put a scope on line PD7 and the USB bus you can see the CP...

Hi,

Some time ago I did some "research" regarding the polling speed.
Also my recent measurements were quite similar.

Ciao, Martin

Hi, Just saw on github that Christian added some new free PIDs 0x27df, 0x27e0, 0x27e1, 0x27e2. That's the complete VID/PID list from USB-IDs-for-free.txt: Table if IDs for discrimination by textual name: PID dec (hex) | VID dec (hex) | Description of use ==============+===============+==============...

Hi SamFozz,

I don't know if you can use different ports, but it is possible to use the pin change int instead of INT0:
viewtopic.php?f=8&t=11057

Ciao, Martin

Hi,

You cannot use VUSB to act as an USB master (e.g. your laptop), it is the implementation of the slave protocol (e.g. USB mouse, keyboard,...). If you want a simple USB master you can use a RaspberryPi with libusb.

Ciao, Martin

Where do you get that doubling of the frequency? The internal RC oscillator of the ATmegas is specified for 8 MHz. The with the OSCCAL register one can push it to around 13 MHz, but that's about it. In general: micronucleus has some code that tries to calibrate the OSCCAL on the frame time of the U...

Hi, Did you also try the 16.5 MHz version? If I look at the F vs. OSCCAL drawing on p. 607 of the datasheet* with split OSCCAL and you use the default starting value of 128 you're in the upper half that starts with 6..6.5 MHz (-> clock frequency 12..13 MHz) and grows. Better use the lower half, star...

Yes, you can do so. I did it for an ATtiny85, have a look at my project here in the forum . You have to define it in the file usbconfig.h ... /* ----------------------- Optional MCU Description ------------------------ */ /* The following configurations have working defaults in usbdrv.h. You * usual...

Very extensive documentation: USB in a NutShell, Making sense of the USB standard.
Ciao, Martin

Hi ulao, I did this in my MIDI project to allow a dynamic naming via an e.g. address switch to have more than one devices connected and recognized. Please have a look at the source code at my bitbucket . Unfortunately I have not time to deep dive into my code, so please try it at your own - but as a...

Hi,

Welcome to V-USB - do you know this project overview? It shows some very tiny HW solutions, e.g. the Haunted USB Cable.

Ciao, Martin

Hi, me again. I've cleaned up the attiny85 midi code at bitbucket , added pwm out and a 2nd analog input. Possible tested I/O functions are: PB0: Digital input or digital output or pwm output. PB1: Digital input or digital output or pwm output (active high LED attached). PB2: Digital input or digita...

Hi, after a quite long time I've added a new demo project - V-USB-MIDI-ATtiny85. Runs on a real cheap development board, e.g. Digispark - available as china clone for about 1..2 € or $. https://cdn.instructables.com/FJI/GKJ2/IDWXMS4L/FJIGKJ2IDWXMS4L.MEDIUM.jpg https://www.mikrocontroller.net/attachm...

No, I can see the schematic - also the other links are working.

Ciao, Martin

Hi,

Have a look:
https://forums.obdev.at/viewtopic.php?f=8&t=6322
http://vusb.wikidot.com/examples (Scroll down to "Other interrupts than INT0 for USB")

Ciao, Martin