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Chemikal
01-12-2008, 06:07 AM
I was just given two Radiometrix BIM-433 Transceivers for use with a Propeller project I have been working on... to make the Propeller able to be controlled wirelessly. I am relatively new to wireless work and the Prop (love it), so I am requesting some help with getting these to communicate with the Prop nicely.

The remote Prop will not need to have a lot of bandwidth... just temperature values, switches, and maybe some stepper motor commands for a future project.

My main goal is to be able to control the remote Prop from my computer... so currently I am guessing I will need a separate Prop at each end, with one end linked into the computer via hyperterminal.


So, after looking around online, I found their main write-up for it: http://www.radiometrix.co.uk/products/bimsheet.htm


From what I can see, that pretty much lays it all out... that page has a sample hook-up and all the details for the programming, but I am unsure how to incorporate that into the Prop... I was told these transceivers do the preamble, etc on-board, and that it just required a serial feed in half-duplex... but I will need a confirmation and definitely some help with the coding.

Thank you so much,
- Josh

Chemikal
01-12-2008, 12:34 PM
anyone have experience or the know how to make this half-duplex connection?

Leon
01-12-2008, 03:57 PM
I got a couple of those a few years ago but never got round to trying them with data. I just tested that I could transmit and receive between them.

All the details you need are in the "RS232 Serial Data" section. You have to do the preamble etc. yourself, it isn't built-in. You should be able to use the serial code in the Object Exchange.

Newer chips like the Nordic nRF24L01 and the TI/Chipcon RF2500 do have all that stuff built-in.

Leon

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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

Chemikal
01-13-2008, 12:14 AM
ah, alright, I have that simple serial code from the object exchange... I guess I can work that out and incorporate the preamble and data starts like the tranceiver wants, but my only major confusion is with it being half-duplex... how do I write the code so it switches seamlessly... I know it has a 3ms switch time, but how do I collect data so it isnt stuck in, say, receive mode when I need it to transmit?

Thanks for your reply,

- Josh

Leon
01-13-2008, 01:10 AM
I think you check the CD pin to see if it's receiving anything. The ones I've got are the BIM3, they have an RSSI pin.

Leon

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

Post Edited (Leon) : 1/12/2008 5:20:46 PM GMT