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Hi,
The RFM12B P is RFM12B´s enhanced power version (500 mW) and seems to be compatible with the RFM12B and Jeelabs libraries.
But it is not pin compatible with JeeNode.
I would like to suggest making a:
header/adaptor ? new JeeNode board ?
to connect that transceiver.
Cheers,
Iñigo
Couldn't you hook it up with a few wires? I'm not sure the P version is used much, nor do I know whether it's even allowed in Europe, in fact. Would be nice if it is, btw...
Hi,
It is one of the projects I'm working on already some time too. Unfortunately it is on idle mode for a long time. But I can give you some head start information.
A 500mW power mode is in most parts of Europe allowed, hence only in a small defined frequcence range: 869,400–869,650 (5) MHz at 10% duty cycle (which means it is only allowed to send at 10% of the time for your application). Look at page 4 in this extract of the Official Journal of the European Union for more information.
So, as far as you tune the module to the right frequency (and you do not send the whole time) you don't break any laws. The tuning is done in the RF12.cpp (rf12initilize). I once calculated the correct values with the RF12 documentation at hand, but apparently lost them again.
To the hardware part: The RF12BP needs two different power levels, the usual 3,3V and for the amplifier dedicated 12V. So it makes most sense to drive the JeeNode with stable 12V power source. This way we can connect the RF12BP directly to the PWR pin anywhere.
My approach was to build an RF12BP Plug. As of this I connected the the two power sources, ground and the interrupt of one Port. For the SPI I did attach some wires.
You see that I also incorporated a barrel plug for power. This is necessary as it is not really possible to drive the RFM12BP with batteries.
As already told I never found the time to try the whole setup. But if it is build as described here, you have to make an other small change in the code. The interrupt has to be changed to the ports interrupt.
Further I already bought a 868 MHz antenna what should extend the range even further. I think transmit ranges around 10km should be possible.
Please inform me if someone makes progress in this project.
Jean-Claude and Loomi many thanks.
I believe adding a more powerfull wireless board is interesting for many of us and hope Jean-Claude find it interestind enough to add a new product to JeeLabs (and modify libraries as needed) in the near future.
It is not needed to use the RF12B P full power (500 mW) in all cases but with that module you can choose the power level you use according to your needs -co location, interference, range, ... -.
Jean-Claude I´d much appreciate if you think about: - designing just the board - adding it to your shop - modifying libraries.
Hope that helps.
Iñigo
Hi loomi,
Saw your photos of your Hope RFM12BP set-up. Was wondering if you have made any further progress? I have just built an Arduino shield version using the RFM12BP. Unfortunately have only been successful over very limited range (approx 5 metres). Still
need to figure out how and when to enable Tx and Rx lines. At present have just tied receive to 3.3V directly. If interested, get in touch and I can send a few photos, schematics and pcb foil patterns your way. Maybe we can get this thing sorted, so as to possibly realise this elusive 3000m range, as from reading these posts there would seem to be several other interested parties?
cheers,
Hi plutonomore,
Unfortunately I didn't progress at all with this project. And I will not until at least April. But I would be delighted to hear more about your set-up.
What did you use as 12V source?
Greets
Hi loomi,
Wow...super fast response! I used a ST Microelectronics L4931CZ120, TO-92 LDO voltage regulator, for the 12 volt supply. This little number can deliver 250mA. Maybe, I might beef this up with a TO-220 device rated at 1A, in a future version.
Sorry to hear you haven't had any opportunity to progress your project. Anyway, if you would like to provide me with an email address I can send you details of my attempts, so far.
cheers,