Soft USB with AVR!!!

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#1
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Hi

its really amazing that USB with AVR is simpler than RS232C -
RS232C needs proper level converter, and USB needs one 1.5K resistor !!!

Just checked the "IgorUSBPlug" - total 4 components
1) AT90S2313
2) 12MHz crystal (no caps !)
3) 1.5K resistor
4) 0.1uF VCC filter capacitor

thats all, the above does enumerate and work as USB device!
trying the same with RS232 more components are needed.

just a notice, maybe not all of the AVRfreaks are not yet aware
how easy USB is with AVR - with non-USB AVR !!!

http://www.cesko.host.sk/IgorPlu...(AVR)_eng.htm

antti

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Very nice project. Thank you for sharing your work with us.

Lee

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;)
not my work, I just shared the info, the author is a young fellow from czech.

I have done some AVR USB stuff self also but have never considered
doing it 100% in software. But the project from Igor really proves it can
be done - it does work.

well my first proto had one wire wrong and on w2000 machine it caused
blue screen kernel exception (no problems on XP) - well after fixing
my hardware the gadget worked both on XP and Win 2000 so I can confirm
that the design really works if build as per info on Igor website

good luck
Antti Lukats

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Do you have any indication on how busy the micro is doing the USB stuff and how sensitive his code is to adding other stuff?

I would like to include something like this as a library in a AVR-GCC project to replace the current RS232/UART with USB, but if it is too much of a delicate balance then maybe I will be opening a can of worms!

Anyone got a handle on the likelyhood of this being possible?

Alex

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Hi Alex

I think the GCC AVR IgorUSB project is already there are sourceforge or
somewhere, seems kinda dead but somebody has registered the project.

no matter how busy the AVR is during the USB transaction it has plenty
of time in between, so it make sense to use AVR SoftUSB for many tasks.

like

ISP Programmer
JTAG Interface
EEPROM Programmer
I"C Interface
SPI Interface
1Wire Interface

a small gadget doing the above and using softUSB would really make
sense, sure it would need to be done with Mega8 or Mega16

antti

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I didn't realize people still don't know about this, it has been posted before on one forum, can't remember which one. The project is absolutely great, no doubt about that. One question though: is there anybody out there that can translate the comments in english ? :)

Bogdan

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Hi all
This is a really well done project. Congratulations to Igor.
For those who want a faster USB link - The Igor project is 1.5Mbit/sec (Low speed USB 1.0) look at;

FTDI chips - 12Mbit/sec (Full speed USB 1.1)
I have just used one of these devices together with a Maga128 (over the top but it was available) to make a USB controller for a model aircraft flight simulator (freeware FMS). The kids love it - only problem is they now think they can fly my model planes!

QuickUSB - 480Mbit/sec (High speed USB 2.0)
I am working on one of these modules at the moment and can transfer 500 bytes of data down a 3m USB cable in 10us. How on earth the drivers/receivers handle data at this speed is beyond me - I thought these speeds were UHF radio only!

With all of this USB stuff us AVR chaps need to remember that the Windows driver end is not simple! If you can use an existing driver that is worth an awfull lot in a professional application!
Regards
Tony

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Hiho

agree on many things, the driver support is important,
the easiest is to use FTDI chips, no knowledge of USB required at all.

Cypress alway had best software support for USB chips (the heart of QuickUSB module)

C8051F320 is a best chip in my opinion because it does not require a crystal!
4 by 5 mm MLP pacakge and thats it a USB and 16KB flash micro.

IgorPlug is cheapest of them all, and it AVR !!

It would be real nice to see similar driver support as FTDI for IgorUSB :)

BTW just looked at the comments in IgorUSB firmware, knowing english
russian and AVR and USB it possible to guess at least 90% of those
comments but without russian knowledge the guess ration would drop to
around 40-50%.

I just suggested to Igot he should make a ATmega8 version where his
USB firmware only implements the bootloader that can upgrade the actual
firmware, lets see if he is up to that :)

antti

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