In this project we're going to assemble the XBee Pulse I/O board--an open-source hardware design which can be used to automate things wirelessly. This hardware is used in "Press any Button in Your Home from a Mobile Phone" project.
We’re going to lead you through step-by-step instructions to build a prototype XBee Pulse I/O board on a breadboard. This board can be used to automate many things around a home and control them remotely. This design is featured in Make Vol. 30 and is used to connect a garage door opener to a mobile phone.
Assembly continues by creating the circuit for the XBee. Set aside your XBee module for now; we'll use it later.
You may insert the XBee breakout board now--note that if you ordered your board from SparkFun you'll have to solder the headers on. You may find as you work you'll add and remove the breakout board to give yourself some space, don't sweat it!
Connect capacitor C4 (10pF) to ground. If you look closely, it will have a little "100" written on it. Connect the other side of C4 to the XBee breakout board's pin 1.
Continue by also connecting pin 1 of the XBee breakout board to your clean 3.3v power rail.
Connect pin 10 of the XBee breakout board to ground.
Now we're going to connect the timer circuit to the XBee. We are going to insert the 74HC123 timer chip IC1 (datasheet). Remember that wire from XBee’s pin 19? Connect pin 1 of IC1 with the wire that is connected to pin 19 of the XBee, inserting the timer chip into the breadboard. Remember, pin 1 is on the same side of the IC as the notch.
Connect pin 16 to the 3.3v power rail and connect pin 8 to ground.
Connect pin 2 to pin 16 using the 10kΩ (brown, black, orange, gold) resistor R1.
Connect pin 3 to 3.3v.
Connect the negative side of 22µF capacitor C1 to pin 14 and the positive side of C1 to pin 15. Connect a 10kΩ (brown, black, orange, gold) resistor R1 between pin 15 and pin 16.
Connect the diode D1 from pin 15 of IC1 to 3.3v, taking care to make certain the striped side connects to 3.3v.
Note the location of pin 13; we're going to use it in the next step. You're almost done!
Place the relay (datasheet) on the board. You may have to gently bend the legs of the relay apart to insert it into your board.
Connect pin 9 to 3.3v. Connect diode D2 from pin 2 to pin 9 of your relay, ensuring that the striped side of the diode connects to pin 9.
Locate the NPN transistor T1 (datasheet). Connect pin 1 (the collector) to the relay's pin 2. Connect pin 3 (the emitter) of T1 to ground. Connect the center pin (the base, pin 2) to pin 13 of the 74HC123 timer chip.
There will be three remaining connections on the relay: the Common terminals (pins 5 and 6), the Normally Closed terminal (pin 1) and the Normally Open terminal (pin 10). Connect a length of wire to one of the Common terminals and another one to the Normally Open terminal. These can be used to connect to your garage door opener for testing.
Finally, connect a 5v-9v power source by connecting the negative wire from the source to the ground of your breadboard and the positive wire of your source to pin 3 of the power regulator VR1.
Here we're showing two stripped wires connected directly to the breadboard. You could also buy a little adapter board such as product #10288 from SparkFun to adapt your power supply without need to cut, strip and tin anything.
Insert the XBee module into the XBee breakout board.
Follow the remaining steps from the article "Press any Button in Your Home from a Mobile Phone" in an upcoming volume of Make Magazine!
Attached to this step is a schematic if you want to see a diagram of what you've built.