RS-232 TTL Board?

[Sidney San Martín]

We're inventorying and even our electonics expert has no idea what this part is. I can only find it in the checklist. Any ideas?

[Doug G]

If you look at Innovation first's website...here (http://www.ifirobotics.com/camera.shtml) You'll see a pic of the TTL converter in the upper right on top, its a small part! Hope that helps...

[jgannon]

It is used to connect the camera board to the RC. Read the camera documentation for more information.

<edit>
Oh, you meant what it looks like, and where to find it? It's in the bag with the IFI camera board (not the camera itself). It's the piece of PCB about the size of a nickel.
</edit>

[Phil Roth]

I think this board plugs into the cmucam2 video board which only has TTL comm. The little converts TTL to RS232.

Learn more about the CmuCam2 @ http://www.seattlerobotics.com/images/CMUcam2_manual.pdf

It's a really cool device and very easy to use. Good Luck :ahh:

[Sidney San Martín]

Thanks! We saw this. One other related question, then - what is the tiny board that goes with it?

[jgannon]

Thanks! We saw this. One other related question, then - what is the tiny board that goes with it?
It IS the tiny board (as I said, about the size of a nickel). The larger board is the IFI camera board, the one that you plug the CMU camera into.

[Sidney San Martín]

Right :)

EDIT: Just saw this in Doug C's post... Sorry!

[jzampier]

Simple Explanation here...

The purpose of that board is to convert voltage levels.
Standard logic levels for ICs and small devices is 0-5v, like the RC or OI.
However, when transmitting data over a wire, it is nice to have more noise margin,
and one way to achieve this is to jack the voltage differential. RS232 voltage levels
do just that.

Your standard legacy pc has a serial port that uses RS232 voltage levels, whereas
the RC has a TTL level serial port. I built one of those modules last spring
to interface the edubot to a matrix orbital lcd screen.

The link below has more detailed information.

http://www.beyondlogic.org/serial/serial.htm#1

I assume, w/o having access to a kit right now... that the rs232->ttl converter
is just a max233cpp chip or equivalent with appropriate connectors.

The digikey part number for that chip is: MAX233CPP-ND
The datasheet is: http://rocky.digikey.com/WebLib/Maxim/Web%20Data/MAX220%20thru%20MAX249.pdf

[Sidney San Martín]

Thanks for this information. I'll be looking at it in much more detail later.