RFM69 sending not packets for specific signal

[AntoineLyon]

Hi,

I need to send a specific message with short preamble and sync in order to activate trafic lights audio for visually impaired people in France.
See attached picture for signal description.

Is there a way to do so with the RH69 library ? I'm looking into it and guessing that the answer is no.

I read maybe a continuous mode could help me, how to do so ? spiWrite ?

Any help will be welcome.

Antoine

[Felix]

Not really, but maybe you could do it by controlling registers directly.
What kind of modulation does it need to be? (x)FSK? OOK? something else?

[AntoineLyon]

OOK

[Felix]

Ok you can search OOK in the forum or check these threads with possible solutions:

https://lowpowerlab.com/forum/rf-range-antennas-rfm69-library/moteino-rfm69-askook/
https://lowpowerlab.com/forum/moteino/new-ook-library-for-moteino/msg17558/#msg17558
https://lowpowerlab.com/forum/moteino/suggest-moteino-revision-to-support-rfm69-ook/
https://lowpowerlab.com/forum/rf-range-antennas-rfm69-library/ook-mode-for-rfm69w-(as-in-jeelib)/msg8644/#msg8644

[AntoineLyon]

Thanks, I had a look on the different links you've provided.
They are using packet mode and byte based preamble and syncs.

The main issue I have is with the preamble and sync. They are very specific, different frequencies I guess and only a few bits for each part.
Is there a way to set the signal to 1/0 totally manually so I could generate the whole "packet" : set to 1, delay 207.5us, set to 0, delay 207.5us, set to 1, delay 207.5us, set to 0, delay 207.5us, set to 1, delay 625us.... etc This is the hard way, but maybe the only solution to be in accordance with this special format (picture for details).

[Felix]

Im not sure how you would do that. The RFM69 library is optimized for FSK packet operation.