Objective Development Forums

I am just searching for different choices and V-USB think is the best and cheapest one, if it can sample my Analoge signal to PC in atleast 250Sample/S. You could easily achieve 250 samples per second by modifying the firmware a little, i'm sure. Actually, that project was exactly how I discovered ...

A typical AVR8 has a maximum sampling rate of ~15 KHz @ 10 bit resolution. Although it would be tricky to buffer this rate smoothly through the USB stack without plenty of RAM.

I see no reason why Atmega644 shouldn't work though i've not tried one myself I have had success with the mega48/88/168 range. You will need to use the zener diode level shift (as opposed to the series diode voltage drop method) so i'd order up a selection of 3.6V < 500mW zeners while you're at it. ...

Are there any special requirements for the zeners? None that I could say, other than those recommeded in the wiki. I am using BZXC3V6 myself but you might find it will work without any level conversion, it really just depends on your system. Give it another go with the zeners, see what voltages you...

My circuit is as shown in the with-series-diodes.png from the circuits directory (except mine is a atmega644) The AVR is driven by a 12mhz crystal According to the datasheet ATmega644 is not rated for 12Mhz operation at < 4.5V. Series diodes will drop the voltage to around 3.5V Speed Grades – ATmeg...

EDIT:

Sorry, I replied to the wrong post though most of what I mentioned in your other thread applies here too.

Fuses perhaps? you really need to provide a lot more info such as F_CPU, avr model, type of zener used, any changes made to usbconfig.h and anything else you can think of that may be important. 'Device not recognised' is such generic error that could indicate so many things that it's impossible to g...

I am wondering about your hardware setup, please tell us more about this. For example are you using the zener diode method, I would assume this as the mega's wont do that fcpu at under 4.5V. IME all enumeration errors with the stock examples have been down to either incorrect fuse settings or disfun...

I am sorry to here that the free support for this free software does not meet your expectations.
Although I must say that the firmware works fine with ATmega32 IME. I guess you must have done something wrong

Well I honestly couldn't say without seeing the whole setup and I must say im not awfully familiar with MFC, I tend to use the wxWidgets api for GUI stuff. My guess is a conflict somewhere between the MFC headers shipped with WDK and those included with MSVC or the SDK. But like I already suggested,...

I dont currently have access to the notebook on which my test setup with WDK installed but IIRC there is some (limited) MFC stuff bundled with the WDK, maybe take a look in the /inc dir? Really speaking though MSVC was never intended for building device drivers, what I have presented here is actuall...

Hi, I've not looked at the Adruino keyboard code but I would guess it should be ok. AFAIK the only thing you need to be careful of regarding interrupts is not use any interrupt lower (higher priority) than that which is used for the usb data line (usually INT0 anyway). The really inportant thing as ...

AL wrote:By the way, could you explain why TWO 1N4148 in the USB power line? Thanks

Answers to this and other questions can be found in the V-USB documentation wiki: http://vusb.wikidot.com/.
See in particular, hardware considerations. Hope it helps.

Hi, for OSCCAL all you really need to do is modify usbconfig.h something like this, in the relevant section. */ #if USB_CFG_CLOCK_KHZ==16500 #define USB_CFG_HAVE_MEASURE_FRAME_LENGTH 1 #include "osccal.h" #else #define USB_CFG_HAVE_MEASURE_FRAME_LENGTH 0 #endif /* define this macro to 1 if...

Have you tried it using the hid-data example as a base?
Maybe this would be a good starting point: http://yveslebrac.blogspot.com/2008/10/cheapest-dual-trace-scope-in-galaxy.html