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Tx rx — Parallax Forums

Tx rx

aaron87aaron87 Posts: 6
edited 2007-09-20 20:21 in BASIC Stamp
I encounter these problems when I'm using the
transmitter and the receiver. (the two attach files
are my program. one is on the TX, the other on RX.)

1. Why it can only receive once after transmitting so
many times?

2. How many data can be sent through RF?

3. Why isn't the synchronizing working? I must add
another rubbish value in order to synchronize it.

4. And my main point is that whether the RF can TX and
RX faster.

Thank you.

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2007-09-20 20:21
    Your attachments didn't attach. Try again.

    The speed of the RF data link is affected by the distance involved and the technique used for transmitting the data.

    The maximum data rate specified is 19.2KBaud, but that would only work reliably in a relatively RF quiet environment and at close range. 9600Baud is a more likely rate for good reliability. Keep in mind that the Stamp's serial I/O is not buffered so, if the Stamp program is not actually waiting for input when the transmitter sends it, the program will not receive the data or will receive it incorrectly.

    For really reliable communication, you will probably need some error checking. Some systems send the same data several times and use a checksum or CRC (cyclic redundancy check) to detect errors and discard invalid information on the receive end.
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