AVR + USB options ...

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#1
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Greetings Freaks,

I need to interface to an AVR project via USB.

The options I have are:
1. AT90USB series of Micros, as they will have more than enough I/O and will have a spare serial port, not required at this stage, but could be usefull.

2. The newer FTDI chips such as the FT232R and FT245R, (both contain internal EEPROM for device customisation unlike the earlier FT232BM & FT245BL)

3. The Silabs CP2102 or the newer CP2103 with 4 GPIO.

Options 2 & 3 will use an AVR eg. Tiny2313/Mega8535.

What do you think is the best solution in terms of ease of use, availability and price?

Has anyone used any of the above?

Ron.

 

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We've just done the standard interfaces, primarily virtual comm port, with the FTDI and usually run without the EEPROM so it was not a factor for us.

If you want to play with the AT90USB, the AT90USBKEY at US$30 is a great way to check it out. Mine was loaded with the sample apps for HID, mass storage, etc. (IIRC others have reported that they needed to load it when they got it.)

If your app can support the cost of a Mega128 (or Mega64 when the AT90USB64x are available) then it would be a great choice--the USB feature is virtually free.

If you are using a $3 AVR, tho, then adding on a $3-$5 FTDI chip may be more attractive.

What kind of device do you need to be?

Lee

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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For flexibility, I use a FT232R with an AVR. I switched from the CP2103 to the FT232R, but both are good.

Smiley

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http://www.obdev.at/products/avr...
http://www.xs4all.nl/~dicks/avr/...

these are firmware-only usb drivers (most promising first). they implement USB 1.1 low-speed and are portable to many AVRs.

http://www.fischl.de/avrusbboot/

this guy made a bootloader with the obdev driver, so you can program the chip via usb. this is the one that i am trying right now, but i am having problems.

that is what brought me to this forum. has anyone heard of these drivers? have you tried any?

-- Karl

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Thanks A/all for your replies.

@Lee

Quote:
What kind of device do you need to be?

For this first project, it is simple I/O. Send one byte and read one byte.

@Smiley
After reading a bit more, and reviewing pricing, it seems like the FT232R or CP2103 with an AVR will be my best option rather than an AVRUSB.

Now to find a down under supplier that has stock, not just catalogs and line cards!

Ron.

 

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Quote:

Now to find a down under supplier that has stock,

Dontronics appears to have stock. At least there was no objection when I added a few to the shopping cart. (Be sure to note the Free Samples notation at Dontronics.)

Lee

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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Thanks, Lee, I'll take a look... The free samples option seems to asume that your company has both a web page and that it will use 1000+/year before being eligible for samples.

But at least they seem to have stock.

 

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The FTDI chips are great. Drivers exists for both windows and linux.
In an electrically noisy environment I've had the FT232 hang sometimes.
It may very well be because of my poor design though...