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View Full Version : Parallax FTDI (USB to Serial) gizmo questions



Buck Rogers
01-23-2010, 12:58 PM
Hello!
In case anyone is curious before I ask my questions, yes it is still the "me" behind the logon handle.
Is this fellow: http://tinyurl.com/9q9o2zˇsimply the actual chip between a USB mini connector and a DB9? If that's the case then, (please don't laugh) yet another firm has the exact same idea behind their break out board: http://tinyurl.com/usb0718ˇ.

I found that guy for sale at a store over in Manhattan that also sells scads of things for the NYU ITP functions, computers and such like. Since a Professor Tom Igoe came up with the ideas of allowing his students to quite literally do everything imaginable in confirming that their study methods work, the place buys stuff like that from that firm.

They mostly buy hardware from a completely different direction which is why I've not been visitng this forum, but seeing a friend of ours on the firm's site:
http://tinyurl.com/lcd0569ˇsee the reference to Terry Hitt, for a BS2 program and of course an excellent comment. (That's what convinced me to return here, and more in a different thread.)

Now the question, can the schematic behind the adapter http://tinyurl.com/9q9o2z (http://tinyurl.com/9q9o2z)ˇbe made available? Basically I want to setup a temporary job using:
http://tinyurl.com/usb0718ˇ so that I can see for myself that the Parallax IDE works on this nifty laptop running Windows Seven without anything resembling a hassle.

And if you happen to be a registered participant of this board, then my humble apologies sir for describing your group that way.

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Buck Rogers

www.gregg.levine.name (http://www.gregg.levine.name)

allanlane5
01-23-2010, 10:29 PM
The big difference between the two is that the $14 FTDI USB to RS232 adapter Parallax is selling has RS232 voltages on the signal pins -- meaning +-3 to 5 volts.

The 'usb0718' uses the FTDI chipset to provide a USB interface to the PC which looks like a serial port, but on the far end (on the USB0718 board, in other words) you have digital I/O -- perhaps 0 to 5 volts TTL, perhaps 0 to 3.3 volts, I'm not sure from the docs at this point.

So, the $14 adapter can connect to any RS232 device. While the USB0718 can ONLY serve as a TTL I/O interface. The Parallax IDE probably will NOT do what you expect it to on the USB0718.

Buck Rogers
01-24-2010, 01:57 AM
allanlane5 said...
The big difference between the two is that the $14 FTDI USB to RS232 adapter Parallax is selling has RS232 voltages on the signal pins -- meaning +-3 to 5 volts.

The 'usb0718' uses the FTDI chipset to provide a USB interface to the PC which looks like a serial port, but on the far end (on the USB0718 board, in other words) you have digital I/O -- perhaps 0 to 5 volts TTL, perhaps 0 to 3.3 volts, I'm not sure from the docs at this point.

So, the $14 adapter can connect to any RS232 device. While the USB0718 can ONLY serve as a TTL I/O interface. The Parallax IDE probably will NOT do what you expect it to on the USB0718.

Hello!
I quite agree. This was why I asked about the schematic first. I wanted to wire one up as a proof of concept study, before I commit to anything else. I am still considering the BASIC Stamp more then the other systems sold from their site, but the easy selling point of the stamp is that they are easy to program.

There is also the original USB2SER, but the gizmo we are discussing is an individual of a completely different style here.
I wonder, are we discussing Zebras here?

I believe I am better off emulating the functions of the USB2SER instead of the USB to Serial (RS-232) Adapter, but since my board is wearing the regular serial adapter, and at the time I didn't need the USB2SER system, and I hadn't begun to upgrade to XP at the time.....

But I believe you see my point. More later.

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Buck Rogers

www.gregg.levine.name (http://www.gregg.levine.name)

Buck Rogers
01-25-2010, 04:08 AM
Hello!
While checking the data sheets for the FT232R, I found the applications for translating its serial data flow at TTL levels into RS232 levels. It was found on page 41 of the data sheet that's local to this system.ˇIt might even be the same one used here: http://tinyurl.com/9q9o2zˇas any of you can see that's why I was curious as to the proof behind its design specifications.http://forums.parallax.com/images/smilies/idea.gif
Granted I may still be reaching here, certainly I may even be wrong. It is a certainty behind all of us. http://forums.parallax.com/images/smilies/eyes.gif

Ideally if it does work, then instead of using a locally designed one constantly I'll switch over to one made by Parallax later.

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Buck Rogers

www.gregg.levine.name (http://www.gregg.levine.name)

Buck Rogers
01-25-2010, 08:09 AM
Hello!
After everything is said and done, I believe I'll probably test my stamp using my regular system.

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Buck Rogers

www.gregg.levine.name (http://www.gregg.levine.name)