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Parallax 433 MHz RF Transmitter Question — Parallax Forums

Parallax 433 MHz RF Transmitter Question

John AbshierJohn Abshier Posts: 1,116
edited 2010-10-12 15:04 in BASIC Stamp
Can this transmitter be used a follows: output of a MAX232 to 22KOhm resistor to transmitter data pin?
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Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-03-01 20:07
    Not really sure on that connection, but it may work...If you're on the MAX232 TTL side I don't see why you would use such a large resistor though.· A 220 ohm would be fine for that.· I am assuming this is to use a computer as the transmitter.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • SteelSteel Posts: 313
    edited 2006-03-01 20:18
    I have a FTDI 232RL feeding a Lynx TXM-433-LR-S Chip (same as parallax 433Tx), and it works jolly.

    I have to slow the baud rate Waaay down to 2400 baud for the wireless signals, but I think that is because of my antennas are not exactly *stellar*
  • John AbshierJohn Abshier Posts: 1,116
    edited 2006-03-01 23:53
    The connector that is available is on the PC side of the MAX232.· The TTL side is driven by a microcontroller.· I used as an example for thinking the stamp to PC connection in the stamp manual.· What I want to do is to put the Parallax transmitter on my robot instead of the wire to the PC serial port.· On the PC side I will use a Basic Stamp talking to the Parallax receiver.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-03-02 01:55
    John,

    ·· The problem is not only the level on the PC (RS-232) side, the data is also inverted so it may not work.· I guess you'd have to try it.· It's designed for TTL level signals though.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • iecnmikeiecnmike Posts: 1
    edited 2010-10-12 15:04
    hello, i´m working on comm-tests with the parallax rf transmitter, but i can´t get to receive the data. I´m using a usb-rs232 cable for the pc, a max232 for the ttl conversion an then i connect the ttl output form the max232 to the data pin but nothing happens... I already tested connecting the ttl max232 output to the same max232 ttl input to see if there´s failures on the i.c. but its fine, only when i connect the transmitter y cant recieve nothing, i would really aprecciate any help,
    Best Regards
    Michael Elbjorn
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