The Existential Emergency Phone is a multipurpose tool for handling all of life's uncertainties. It can be used for both dialing out and calling in. The way that it works is that when you pick up the handset, the telephone makes a call using a custom cellular module to a list of predefined phone numbers. Whether the phone calls a list of people you know, a list of people you don't know, or randomly dials strangers in your area code, is really up to you. Alternately, the number can be distributed to people with existential emergencies and they can dial in for others to answer. The many manners in which the phone can be used makes it well suited for processing existential emergencies both outgoing and incoming.
Step 1: Go Get Stuff
You will need:
(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
Build the circuit as drawn in the schematic.
Do not worry yet about connecting wires to external components.
Step 3: Attach Wires
Attach a 6" stranded red wire to the Vin pin of the 7805 regulator, and a 6" stranded black wire to ground. This will get attached to the power jack.
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 5: Attach the Antenna
Attach the antenna to the shield by threading the two together.
Step 6: Audio Wires
Affix shielded audio wires to the board. The inner wire should go to signal. The shielding and outer wire should go to the corresponding signal ground.
Step 7: Open the Case
Open up the telephone by removing the screws from the bottom of the case.
Disconnect the handset while you are at it.
Step 8: Remove Brackets
Remove the brackets that are there for potentially holding a dial pad.
This is easily accomplished by drilling through the metal rivets holding them in place.
Step 9: Wooden Bracket
Download the attached file.
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
Use the bracket to mark mounting holes on the bottom of the case.
Drill through these marks with a 1/8" drill bit.
Step 11: Mount
Remove the cellular shield from the Arduino.
Affix the Arduino and the circuit board to the bracket using nuts and bolts.
Step 12: Reattach the Shield
Reconnect the cellular shield to the Arduino.
Step 13: Wire it Up
Connect the red solid core wire that is connected to the 5V rail on the circuit board is the 5V pin on the Arduino.
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
Using the mounting holes drilled earlier, fasten the wooden bracket to the metal base of the telephone using nuts and bolts.
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
Cut the handset jack free from the telephone.
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
Before you start, place shrink tube onto all of the jack's wires and also the shielded audio cables. You will obviously not be able to slide on the shrink tube after it is soldered.
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
On the inside of the telephone, figure out which wire is the green wire coming from the telephone's line jack. Cut this wire, slide some shrink tube over the telephone end (not the jack end), and solder the end connected to the phone to the stranded green wire on the circuit board.
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
Make a mark about an inch to the left of the handset jack. The idea here is to install the power jack in a location where it is not going to bump into stuff.
Drill this mark with a 5/16" drill bit.
Step 19: Power Jack
Remove the power jack's mounting nut, pass it through the hole, and then tightly re-thread the mounting nut.
Step 20: Paint the Sign
Laser cut and etch the sign if you have not done so already using the attached template. Make sure to leave the acrylic's protective coating on.
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
Coat the front panel of the phone with contact adhesive and the back side of the acrylic panel.
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 black stranded wire from ground on the circuit board to the central terminal on 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
Stick the cellular antenna to the backside of the front panel with strong double-sided tape.
Step 24: Clean Up Wires
It is generally good form not to have a rats nest of wires inside of this thing.
Tidy up the wiring as best you can by zip tying the wires together.
Step 25: Program the Arduino
Upload the following code to 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
Close the case, reinsert the screws, reattach the handset, and place it back on the hook.
To get started, plug it in, wait a minute or two for the cellular network to initialize, and you should be good to go.