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Wireless RS-232 for Palm and Other Devices?

Posted by Cliff on from the if-it-works-for-networks-why-not-serial dept.

The Serial Anonymous Coward asks: "I have all these old RS-232 interfaced items (my palm pilot, trg pro, etc.) and i really like them for what they do, but can't understand why there aren't any dirt cheap limited range wireless serial ports for them? Just want a small dongle to hook into my desktop, and the same for my palm pilot--so in my house, within a small distance (50 feet, maybe more if possible) I can use this to browse the web, check my e-mail, whatever. I mean I don't need much faster than 56k, and less probably wouldn't be bad (how fast can a palm process the data anyway). I know the laplink people had a product like this years ago--didn't last long, I'd love to get a hold of something similar....anyone working on it for a hobby? I don't need bluetooth (but a serial -> bluetooth adapter would be fine)"

3 of 17 comments (clear)

  1. Where are *YOU* looking? by JCMay · · Score: 5, Informative

    (Flips to the back of most recent Circuit Cellar magazine, #138, January 2002: "Measurement and Sensors")

    At the bottom of page 85 is a 1/3 page ad for Abacom Technologies. They sell ISM (418 and 433 MHz) band Rx and Tx modules that could be pressed into service for what you want. One drawback-- half duplex only. But it's a complete 38,400 bps transiever for $140.

    On page 47 Radiotronix has an ad, but their stuff is limited to 4800 bps.

    On page 32 there's a feature article about a wireless (RF) irrigation control system. It's not exactly what you want, but it will tell you some of the things to think about.

    (Gets out MX-Com catalog)

    Their CMX017 transmitter and CMX018 receiver can be used to build such a device. For your speeds they'll do fine (I wanted 10 Mbps; they won't go that fast!).

    (Looks at Xilor pamphlet)

    Nope; their stuff looks like remote controls (keyles entry stuff) only.

    (Gets out Maxim selector guide)

    Hmm. These guys have a range of 1800 MHz PCS and 800-1000 MHz tunable tranceivers. These could work.

    No, none of these are "turnkey" solutions and they all have their drawbacks. It's not true that stuff isn't out there. The Abacom Tech stuff is very, very close.
    You just have to realize that this is a very small market; just because we have PDAs (I just got a Visor Prism for Christmas!) doesn't mean there's enough PDA owners to support such a device.

    I might like one, but right now my latest hardware project will be making a battery charger for the Prism that doesn't cost the $50 they want for a cradle. My computer isn't on the way out of the door in the morning; it'd be nice to have a non-HotSync-able cradle by the door just for charging.

  2. If money is no object... by 1101 · · Score: 5, Informative

    and dont mind bulk, an Orinoco 802.11 to RS232 converter might be good. Hey, it works with everyones favorite 802.11 card.
    Then again, whats wrong with the cable?

    --
    Slackware is not dead
  3. Building one now . . . by RGRistroph · · Score: 3, Informative

    Using a PIC 16F877 connected to a MAX232 (serial port) and a pair of receiver/transmitters from Laipac:

    http://laipac.com/products/wireless.htm

    (I'm using the RLP916A and the TLP916A on that page).

    I haven't gotten the radios in yet. I have the other parts though. A transmitter/receiver pair ends up costing $20 including the shipping, the PIC and the MAX232 make up about another $6 if I remember correctly.

    If anyone is interested in these, email me in a couple of weeks and see if I got it working.