Building the ProMiniAir

Building the ProMiniAir

Note: I am out of PCBs for this project and since they sell very infrequently, I won’t be getting anymore unless there is a demand. If you are interested in getting some of these, drop me an email

This is an easy to build board that once operational will give you an Airwire Receiver with DCC logic level output. The software provided also decodes the DCC signal into byte packets and provides a servo interface so you can use them to do other things if you wish. This is sold as a PCB only, you will have to order the other components individually.

The Github repository for this is located here:
AirMini Code

Parts List

The ProMini is really only two components, the Arduino ProMini and the radio module. The other parts are just passive components to tie everything together. These are easy to find parts and are available from a variety of sources, Adafruit, Pololu, Sparkfun, Mouser and others.

Here is a list of parts and links from Digikey so you only have to order from one place:

  • 3.3v Surface Mount Voltage Regulator
  • 10K Resistors
  • 20K Resistors
  • Pin Headers

    The Promini itself is not available from Digikey (I couldn’t find it there anyhow) but you can get one for $10 or so from Sparkfun.
    Make sure you get the 5v 16Mhz version.
    Sparkfun ProMini
    The radio module is fairly generic and can be had from quite a few places. A cheap one is on Amazon:
    CC1101 Radio Module
    As with most things, you get what you pay for and the cheaper modules often don’t have much of a range. This one is a bit better:
    ElecHome CC1101 Module
    If you want the maximum range out of this you will need the top of the line radio:
    Anaren Radio Modem

  • Building the Board

    This image shows all of the parts. The Radio module, the ProMini Board. Passive Components and the PCB.
    The first step with the board is to solder on the voltage regulator for the 3.3v we need for the radio module. Use an alligator clip (or similar) to hold the small chip in place and solder the three lower pins. Don’t worry about the tab, it’s not connected to anything. Another method is to superglue the tab, once it’s dry, solder the three lower tabs.
    Next, install the Pin Headers for the ProMini. Break the long header pins off for the correct length for both sides. Solder one pin, check alignment, tweak if required. Then solder all of them in. Long side up is the best way, this gives you good access to all of the signals if you want to take a look at them. Note that the two pins at the top of the ProMini will have to be trimmed so the programming adapter fits.

    After the pins are soldered in, do a test fit for the Arduino board. After making sure it fits, (it should go in easily) remove the Promini and solder in the header pins (at the top of the board). This will let you plugin the the Sparkfun FTDI Basic Breakout Board (as shown) to attach to the Pro-mini. This has already been done in this photo. It’s important to do these pins at the top of the Arduino board first as you will not be able to get to them after you solder to the PCB.
    Solder in the resistors. These are voltage dividers so we can interface the 5v promini outputs to the 3.3v inputs of the CC1101 modem.

    Solder in the servo pins.

    All the pins and components soldered together.
    All three sub-assemblies.
    Completed Module