RF Tranceivers & flow control

Tumbler

Hi,

The parallax RF tranceivers with flowcontrol. Is it possible?

Mike Green

It's possible to do it in software (at both ends of the connection), but not in a way that's compatible with say the flow control options in PBasic. The way you'd have to do it would be to have one program (at one end of the connection) periodically ask the other program (at the other end) whether it's ok to send data and check that status before sending anything. This communication back and forth would have to be hidden from the actual data sent. This is the way Bluetooth and xBee operate. Rather than having it built into the device, you'd have to do it all yourself in your own software.

Tumbler

Interesting Mike,

Only i see some troubles when using more than 2 devices.
Nice project to test with.

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stamptrol

You can implement a multi BS2 system just as Mike has outlined.

One device has to be master and polls each other (slave) BS2. If the data string includes a correct address byte, that BS2 responds. The master orchestrates the incoming data and acts on it or sends it to another slave as required. These systems can have 4 or 10 or many times that units in the network.

For further details on this type of communication scheme Google "half-duplex communication" or have a look at Jan Axelson's book Serial Port Complete which covers the topic exhaustively, including Stamp examples.

Cheers,

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Tom Sisk

http://www.siskconsult.com
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Tumbler

I think i have something.

stamptrol

The only disadvantage with what you've set up is that the slaves are sitting there chattering away all the time. It is much more efficient for all slaves to sit there only listening for their ID to be called. Then, only one slave answers and the master goes on to the next slave.

Cheers,

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Tom Sisk

http://www.siskconsult.com
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