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by Luis Bruno

When you´re tearing downhill on your snowboard, it´s a little distracting to take off your glove and dig out your iPod just to, say, hit pause. Instead, build this simple radio-frequency ID system and control your iPod by waving your hand in front of your coat.
A tag sewn into your glove sends instructions to a reader stashed in your pocket.

Unwire Your iPod
****Cost:
$161
Time: 6
Hours
Easy | | | | |
Hard

Parts

Assemble the Electronics:
This step requires some soldering; see the diagram above

Connect:

  1. The remote control to the reed relay
  2. The RFID reader to the carrier board
  3. The reed relay to the microcontroller
  4. The switch to the nine-volt battery
    harness and to the carrier board

Program the Board: Tell the microcontroller to read and process a signal from the RFID tag by plugging the microcontroller into your computer with a serial cable. Download the code here and copy it from your PC to the
microcontroller.

**
Stash and Use:** Slip an RFID tag into your glove, and plug the iJet remote receiver into the iPod. Stuff the electronic parts into a chest or sleeve pocket. Wave your glove within four inches of that pocket, and the music will pause, just in time for you to hear your friend shout â€Avalanche!â€

For further instructions, see the next page

Once you´ve mastered the pause function with your â€touchless switch,â€
how about adding fast forward or reverse functions? As you’ve
probably guessed, adding more functionality, increases this project´s
complexity. Luckily, it´s just a wee bit tougher.

The construction steps are fairly straightforward:

  1. Each additional control option will require a new Reed Relay.
    You will also need a new RFID tag for each additional control option.
  2. Solder one electromagnet pin of the relay to ground (i.e.,
    Vss -). Connect the other electromagnet pin to another free port on
    the Parallax Super Carrier Board (e.g., P4).
  3. Wire the two remaining relay poles to switch pads for your
    chosen remote control option (e.g., skip to next track; fast
    forward). Use the same technique that you used for the Pause/Play
    button.

That´s it; well almost. The more complex part of this â€advanced´ project involves the
programming of the microcontroller. Unlike our pause-only â€touchless
switch,†this added functionality project requires the reading and
interpreting of specific RFID tag IDs.

A specific tag ID is assigned to each of these additional functions.
When that tag ID is read, the code will send a trigger signal to the
appropriate microcontroller port and toggle the selected relay.Therefore, you will need to assign a specific tag ID to a specific
function. Don´t lose that tag, however. Only that tag can enable and
play its assigned function.

  1. You have now physically wired a new iPod remote control
    function to a specific port on the BASIC Stamp microcontroller. In
    order to control this new iPod function, you must modify your
    original Pause/Play program.
  2. Program the microcontroller for enabling specific BASIC Stamp
    ports based on reading different RFID tags. First you will need to
    read the unique ID number that is registered for each tag. You can
    download some sample code from the Parallax Web site that will allow you to read a tag’s ID. Now that
    you have correlated a tag ID and Super Carrier Board port number with
    an iPod remote control function, you can modify the free Parallax
    code for activating a specific port based on the “reading” of a
    specific tag.
  3. Stitch each RFID tag into a different location (e.g., left
    ski glove for Pause/Play and right ski glove for Fast Forward).
  4. Plug the iPod remote control receive into the iPod’s docking
    port and the advanced, multifunctional touchless switch is ready for
    use.

Now hit the slopes and keep on track-your iPod’s track, that is.

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