this is jason from oklahoma i just wanted to let you know that the cable you made me is working great. also, i found that you can easily make it look finished by adding a little sugru to the exposed wires.

http://www.sugru.com/

thanks for all the help earlier this month!

we hope to have our space, OHM (www.ohmspace.org), up and running soon!
jason

Some more info about my device:
http://kintel.net/public/PL2303-back.jpg
http://kintel.net/public/PL2303-front.jpg

Descriptor Version Number: 0×0110
Device Class: 0 (Composite)
Device Subclass: 0
Device Protocol: 0
Device MaxPacketSize: 64
Device VendorID/ProductID: 0x067B/0×2303 (Prolific Technology, Inc.)
Device Version Number: 0×0300
Number of Configurations: 1
Manufacturer String: 1 “Prolific Technology Inc.”
Product String: 2 “USB 2.0 To COM Device”
Serial Number String: 0 (none)

-Marius

For now, zoom in on the photo in the blog post, there’s a spare pcb/usb DKU-5 that’s lying on the table. This pcb has markings for an missing 8 pin IC, making the blob chip the only chip used…

-r. miloh

Anyway, looking at the link you posted, it appears to me that the DKU-5 cable contains a second chip in addition to the PL2303. Although it has no markings, I’d expect this to be an inverter, perhaps combined with a level shifter, perhaps to 3.3V if the PL2303 in question is the 5V version.
Doing an oscilloscope test on the TX pin of the 2303 and the TX you give to the Volksduino should set this straight though.

This discussion feels like it should be wikified btw…
I’ll make some pics of my existing cable as well – tomorrow…

links:

DKU-5 on Ebay…
http://cgi.ebay.com/DKU-5-Data-Cable-Driver-Nokia-Phones-/190452282740?pt=PDA_Accessories&hash=item2c57d73574#ht_500wt_1090

There’s more information about modifying DKU-5′s and a good set of links at the end of this post:
http://jethomson.wordpress.com/2010/02/21/diy-usb-to-serial-cable-for-3usd/

Of course, this extends a bit beyond Arduinos as most WRT devices or other embedded computers also use TTL serial ports.

If you link to a specific item in such a HK shop, I’ll buy the same cable and do some further tests on my side.

FYI, this is the one I bought:
http://cgi.ebay.com/USB-RS232-Serial-9Pin-Cable-Adapter-PDA-GPS-/350341616960?pt=LH_DefaultDomain_0&hash=item53dacbded1#ht_3705wt_1002

..might be the same as this one:
http://cgi.ebay.com/USB-RS232-Serial-9Pin-Cable-Adapter-PDA-GPS-/360153079505?pt=LH_DefaultDomain_0&hash=item53dacbded1#ht_4425wt_1002

The source for DKU-5 cables was an Ebay ‘buy it now’ auction in HK. The lowest price I have seen from ebay’s USA site is at $1.00US from China.

As far as I can tell, the DKU-5 uses prolific 2303H or 2303HX (pin compatible to the older). It’s a chip on board blob, so I, like you, can’t tell for sure what it is. As far as the TTL serial being inverted, I haven’t had any trouble using the cables with Arduino softare and Volksduinos. Have you had trouble with a cable build?

-r. miloh

1) Where do you get $2 DKU-5 cables? I cannot find anything under EUR 5 here (Austria), not even in chinese eBay shops.
2) I _can_ get hold of $2 Prolific usb-to-serial adapters (some PL2303 variant – not sure how to identify the chip under the black blob), but they all output the TTL serial inverted (active low instead of active high which is what AVR’s expect). Did you encounter smth. similar?

Cheers from the Metalab