Objective Development Forums

Yeah, I dont see how it woudl work without the zeners. Being compatible on hubs and ports that is. Right, without the zener diodes there is no level conversion taking place, thus violating the electrical spec for USB. got the 1K8 resistors, works with and without the hub now! Some, possibly most, h...

You can load hexes and when you power cycle the device it will run the hex fine. Form what I can make of it that is all it is meant to do, what else are you expecting from 'bootloader mode'? WORKING WITH THE BOOT LOADER ============================ The boot loader is quite easy to use. Set the jump...

There is something I don't get. I got it working only when the reset pin is grounded. it wont got into bootloader mode and stay in bootloader mode If the reset pin is grounded then surely no code can be running at all. The device enumerates when held in reset ??? Isn't there a way in the source code...

2k2 will be fine to test if that is indeed your problem. It is good practice to have one in any case.

You got it, though personally I think 1K is a bit 'strong', I prefer using 10K myself.

That schematic shows pin 3 connected directly to ground. If you have added a switch between pin 3 to ground then you should also add a resistor from pin 3 to Vcc, a 4K7 - 10K should be fine here. Look how it's done (with a 1K resistor) on the reset pin [edit]Not sure if you're meaning pin 3 or PD3, ...

The only way I can make v-usb enummerate on all the PC's I have access to is using 500mW 3V6 Zeners & 1K5 pull-up as per the wiki. However there is one bit I have never quite understood. And 3.6 V is better than 3.3 V because 3.3 V diodes yield only ca. 2.7 V in conjunction with an 1.5 kΩ (or mo...

ps2chiper wrote:The default Port D Pin 3. I have it going to a button than to ground.

I suggest you also attach a pull-up resistor to V+ otherwise the input will 'float'.

Given that you are using INT0 for vusb I guess it should work atleast some of the time, even if unreliably. Perhaps if you show the code where you send the data, someone might be able to see where you are going wrong.

CDC requires bulk endpoints which are forbidden for low speed devices by the USB specification. However, most operating systems don't care and CDC works. There are still many drawbacks involved (see disadvantages below) and the main purpose of implementing this class is to simulate older devices wh...

I search on the web easy example for USB HID using. But I don't find easy code. question for all. 1. some code use only 2-avr pin some code use 3pin. what is differ 2pin 3pin???? 2.I use cdc - 232 , easy , there are function to read 8bytes from usb and function to write 8bytes, have any code for ea...

I just have problem with real time reading and decoding RFID tag. but try use 20MHz crystal and try found position where can I disable - enable interrupt what I need for RFID. The only practical way to do this would be to use a different interrupt for RFID, as your program must not use a higher pri...

Hi all. I start with this project http://www.recursion.jp/avrcdc/cdc-232.html and connect LCD (now work) and connect RFID reader That wouldn't have been my first choice given that it violates the standard for low-speed USB and it does require a driver (that doesn't work with 64-bit win vista/7) not...

dzairo wrote:I make schematic, PCB and all for make this project , Is there any one for help with this?

What exactly do you need help with? Seems to me that the HID-data example project that comes with the V-USB source, would be the perfect place to begin.

AcuScorp wrote:I can´t comprehend how works USB communications.

A good place to start would be here http://www.beyondlogic.org/usbnutshell/usb1.htm