Step 1: Go Get Stuff
(x1) red 2500-style no-dial phone
(x1) Arduino Uno
(x1) Cellular Shield
(x1) Ag1170 SLIC
(x1) PC Board
(x4) 1N4004 diodes
(x1) Prepaid SIM card
(x1) BZT03C82 or P6KE82 diode
(x4) 0.1uF ceramic capacitors
(x1) 220uF, 10V, Rubycon ZL capacitor
(x1) 100uF, 6.3v capacitor
(x1) 10uF, 25v capacitor
(x1) 1uF, 25v capacitor
(x1) 10ohm resistor
(x1) 7805 regulator
(x1) quad band antenna
(x1) 6" x 6" x 1/8" acrylic (bracket template below)
(x1) 6" x 6" x 1/8" mat white acrylic (sign template below)
(x1) M-type power socket
(x1) 9V / 1A power supply
(x1) Black acrylic paint
(x1) Double-sided tape
(x1) Contact adhesive
(x1) assorted shrink tube
(x1) assorted zip ties
(x1) assorted nuts and bolts (4-40 and 6-32 ideal)
(x1) 22awg wire (stranded - red, black, and green)
(x1) 22awg wire (solid - red, black, and green)
Step 2: Build the Circuit
Do not worry yet about connecting wires to external components.
Step 3: Attach Wires
Connect a 6" solid core red wire to the circuit's 5V rail. Connect a 6" solid core black wire to ground. These will be used to power the Arduino.
Also attach a 6" stranded red wire to the ring pin of the SLIC. Attach a 6" stranded green wire to the tip pin of the SLIC. These wires will be connect to the ring and tip connections on the phone.
Finally, connect a 6" solid core green wire to the F/R pin of the SLIC , another 6" solid core green wire to the RM pin of the SLIC, and a 6" solid core red wire to the SHK pin of the SLIC. These wires will connect to the Arduino to determine the state of the phone receiver and controlling the telephone ringer.
Step 4: Prepare the Shield
Step 5: Attach the Antenna
Step 6: Audio Wires
Step 7: Open the Case
Disconnect the handset while you are at it.
Step 8: Remove Brackets
This is easily accomplished by drilling through the metal rivets holding them in place.
Step 9: Wooden Bracket
Make a wooden bracket based on this template.
I laser cut mine, but you can get the same results with a jigsaw and a drill.
Step 10: Drill
Drill through these marks with a 1/8" drill bit.
Step 11: Mount
Affix the Arduino and the circuit board to the bracket using nuts and bolts.
Step 12: Reattach the Shield
Step 13: Wire It Up
Connect the black solid core wire connected to ground on the circuit board to the ground pin on the Arduino.
Connect the green wire connected to the F/R pin on the SLIC to pin 7 on the Arduino.
Connect the green wire connected to the RM pin on the SLIC to pin 8 on the Arduino.
Connect the red wire connected to the SHK pin on the SLIC to pin 12 on the Arduino.
Step 14: Attach to Case
Make certain that the bolts pass upwards and that the nuts will be located on the inside of the case.
Step 15: Prep the Jack
For all four handset wires, leave about an inch to work with. If you keep it too long, you may end up with static or audio interference.
Step 16: Attach the Jack
Connect the shielded signal wire from the microphone to the black wire on the jack. Connect the microphone's shielding to the green wire.
Connect the shielded signal wire from the speaker to the red wire on the jack. Connect the speaker's shielding to the white wire.
Slide shrink tube over all of the exposed connections, and shrink it with a heat gun to keep it protected.
Step 17: Wire the Ringer
Repeat the same process for the incoming red wire.
Slide the shrink tube over both connections and secure it in place with a heat gun.
Step 18: Mark and Drill
Drill this mark with a 5/16" drill bit.
Step 19: Power Jack
Step 20: Paint the Sign
If you don't have a laser cutter, cut it out the old fashioned way and then stencil the writing, or create a sticker on transparent printer media.
Anyhow... assuming that you have a laser cutter...
Now is time to paint over the etched writing with black acrylic paint. Put one coat horizontally, wait for it to dry, and put another coat vertically.
When the paint has fully dried, peel off the coating. To remove the coating from the islands inside the letters, you can gently use a toothpick or craft knife, while being careful not to scratch the paint.
Step 21: Glue the Plate
Wait for both to dry.
Align them, and then press them firmly together for a strong bond.
Step 22: Solder the Power Jack
Solder the red stranded wire connected to Vin on the voltage regulator the terminal to the right of the power jack (as pictured).
To be certain that you get it right before connecting it to the circuit board, you may want to plug in the power and test the voltage of these terminals with a multimeter.
Step 23: Affix the Antenna
Step 24: Clean Up Wires
Tidy up the wiring as best you can by zip tying the wires together.
Step 25: Program the Arduino
To change who is getting called take a look at where it says "//List of phone numbers to call."
Step 26: Put It Back Together
To get started, plug it in, wait a minute or two for the cellular network to initialize, and you should be good to go.