Registered: Oct 1999
Location: Cincinnati, OH
Posts: 109

I've read, and even posted, messages before on the general concept of connecting the Visor to a digital cellular phone to enable wireless Internet access.

Finally, I've found a cable to connect my Qualcomm QCP-2700 to a serial device. However, seeing as how the Visor is USB, this doesn't help.

I've heard the Visor supports both serial and USB via some trickery of the pins.

What would it take to make the final piee of the puzzle (a cable to connect the Visor's connector to a serial cable)? I'd even be up for builindg my own, but I don't know where to start.

Registered: Feb 2000
Location:
Posts: 144

I received an email from Handspring CS about two weeks ago that they are going to release a serial cable for the Visor *soon* - whenever that is - because of the high demand. If you can wait a little more, I would probably wait for the Handspring cable. (On the other hand, who knows when 'soon' is going to be ;-) )
I also know that there is at least one other member out there who is currently trying to make such a cable by himself. You can find the post somewhere in the archives.

Hope this helps...

Registered: Dec 1999
Location: Connecticut USA
Posts: 2682

It's not pin trickery... the Visor speaks both USB and serial. As far as I know, the serial cradle will do what you want (might need a null modem adapter) until a real serial cable is available.

One thing to keep in mind here is that the Visor signals are TTL level, not RS-232, so a converter circuit is needed to connect to a serial device. The cradle has this built-in. A cable needs to offer it as well. There was a discussion here about a do-it-yourself serial cable which I am in the process of building myself (just don't seem to have any time).

One other note... HS DevSupport told me that they would not be offering a serial cable themselves but that one of their vendors, ATL, might be. I've not confirmed this yet.

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MarkEagle - Ice is nice!

Registered: Nov 1999
Location: Mt.Vernon, IN, US
Posts: 18

I am trying to make a homebuilt Serial Cable for my Visor. I have obtained an RS-232C female to female serial cable from Radio Shack. I bought one of the Handspring "hotsync connector kits" from ATLLINK.COM. I am trying to wire everything up to do a serial hotsync with my Win98 machines. I grabbed the Visor pin-out diagrams from the Developers handbook and went to www.beyondlogic.org/serial/serial.htm to find the pin-outs for a D-shape 9 pin serial port. I have wired the RX(1), TX(8), and Ground(4) to the 2,3, and 5 pins respectively on the serial cable. I short pins 3 and 4 of the Visor to begin a hotsync, however, I don't get anything happening at the computer end. It doesn't seem to recognize anything. I know the Visor is putting out TTL levels instead of those at RS-232. Do you think all I need is a TTL to RS-232 voltage level converter on the TX and RX lines and then I should be set? How far have you gotten on your custom cable? Any tips? Thanks a bunch!

-matt

Registered: Nov 1999
Location: Mt.Vernon, IN, US
Posts: 18

I forgot the mention that I have tried the custom serial cable hotsync with the Serial port wired as a null modem as well. I.E. I connected serial pins 4,6, and 1 together and also connected serial pins 7 and 8 together to simulate a "null modem" type connection to the Visor while the Visor pins where connected to the serial cable in the fashion I describe in my previous post above.

Registered: Dec 1999
Location: Connecticut USA
Posts: 2682

Yes, you will need a TTL-RS232 conversion circuit. Check out this thread. It contains links to schematics, etc. I have built 3 serial cable based on this design and they work great.

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MarkEagle - Ice is nice!