Computing stuff tied to the physical world

Meet the RFM12B Board

In Hardware on Feb 2, 2011 at 00:01

With the RFM12B becoming a nice low-cost option for low-volume wireless communication, and the RF12 library proving to be a solid software driver for it, it’s time to generalize a bit further…

Say hello to the new RFM12B Board:

Dsc 2448

This board adds a voltage regulator and 3.3V/5V level conversions, to be able to use the RFM12B on 5V systems such as the various Arduino’s out there, the RBBB, … anything you want, really.

There are 8 pins on this board, of which the 8th is a regulated 3.3V supply which can be used in other parts of the circuit – the voltage regulator will be able to supply at least 100 mA extra on that supply pin.

The other 7 pins are:

  • +5V
  • Ground
  • SPI clock (SCK) – Arduino digital 13
  • SPI data out (SDO) – Arduino digital 12
  • SPI data in (SDI) – Arduino digital 11
  • SPI select (SEL) – Arduino digital 10
  • IRQ – Arduino digital 2

Just hook each of those up to an Arduino, and you can use the RF12 library as is!

Sample output:

Screen Shot 2011 02 01 at 22.08.14

Look ma, just like a JeeNode or JeeLink!

With an 8-pin stacking header and a bit of bending, cutting, and soldering two wires (I used a jumper wire, cut in half), you can even stick this thing right onto an Arduino:

Dsc 2449

But of course using a normal solderless breadboard and some wire jumpers will work just as well.

Note that this board can also be tied to 3.3V systems – just use the bare PCB (and short out three solder jumpers), which then becomes a breakout board for the RFM12B. No need to mess with the 2.0 mm pin/pad distance on the RFM12B module itself.

Docs can be found in the Café, and the kit/pcb is now available in the shop, as usual.

  1. For simplicity sake I hope you make a version in the Arduino Shield form factor. Maybe you can integrate it into the Plug Shield. I think it might open JeeLabs up to a new audience.

    • Hi Matthew,

      When you say “integrate it into the Plug Shield” are you refering to the Arduino shield compatible board, described in the article, “How to build a JeeLabs Input Plug Clone”?

  2. I was following your notes to create a RFM shield and finished it last night and the RFM module has worked fantastic. If anyone wants the Eagle files leave a comment and I will publish them online. But for now keep up the good work on your articles they have helped in developing a cool home monitoring system.

  3. Another very neat little board from the labs of Jee.

    Hopefully this might attract a few more 5v users to come and have a look over here and see what they’re missing out on :-)

  4. real nice! now we can get our bored arduinos to talk to our happy jeenodes!

  5. Great job!!! Very good idea!!! Well done my dear friend JC!!!

  6. Sorry for the delay had to recove from the cyclone Yasi that just tore through the place. But as promised you can find the shield files at

  7. I am not sure if my last post worked, but to get the Arduino shield Eagle files go to This design is for a single sided home produced PCB but you can modify it to suit your own requirements.

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