USB2SER Adapter

[livinlowe]

Just got mine in the mail today from parallax. Man is this thing tiny! Smaller than the BS1 Serial adapter, I'm scared I'll lose it!!  :o

[JonnyMac]

Don't I know... I used to have two!

[BigRez]

Got mine today - it came with a neat little retractable USB adapter.  Anyway, I cannot seem to figure out how to connect it to the uMP3...

This is version C of the USB2SER device.  The picture on the Parallax web site matches this tiny thing, but they don't have documentation for Rev C. 

[JonnyMac]

I have an older model but the pin-out should be the same.  If you look on the bottom of the board, with the pin-connector facing left, you should see:

RES\
TX
RX
VSS

To connect to the uMP3 you're going to use three of the four connections, the RES\ will not be connected and will dangle of the end (this is okay).  When you plug the USB2SER into the uMP3 the componets side will be facing the edge of the PCB.  

VSS --> G
RX --> T
TX -->
RES\ --> not connected

Please check all of your connections very carefully before powering up.

[JonnyMac]

Okay... maybe I spoke too soon; I just opened the Rev B docs and it looks like you may have to face the component toward the inside of the uMP3 with that version.  Based on the docs, the pins are in the same order, they've just been mirrored from the Rev A (that I have, in the photo above).  Not sure why Parallax would do this, but it probably has something to do with the new FTDI chips and layout of the PCB.

[JonnyMac]

One more follow-up for those that are wondering... "Can I program a Prop-1 with the USB2SER?"

Yes.  Plug it into the Prop-1 with the VSS pin aligned with >> -- I just downloaded and ran a test program.

[BigRez]

There are no markings on the Rev C version and wouldn't you know, the connections are different than the Rev A version.  Parallax just posted the change to their web site which specifies that the B and C versions have the same connections.  (We were left to guess up to this point.  But after connecting as above, I knew the Rev C was different than Rev A.)

So, this means the B and C version orientation is different than the picture above.  I've included a picture of the Rev C showing proper orientation.

[JonnyMac]

Thanks, Mike.  As is obvious by the picture in my post, I have a Rev A version of the USB2SER.