Editing Payphone

{{access}}
{{blackbox}}You are standing at the Payphone keypad of the [[Gate]] [[access]] system at the [[fence]] outside Noisebridge. Behind you is [[Parking]] and the [[Street]].
'''EXITS:''' [[Gate]], [[fence]], [[Parking]], [[Street]]
{{cursorboxend}}
{{headerbox}}'''Project Payphone''' is a modified phone that serves as a keypad for entry to the space.
{{boxend}}

=Project Payphone Access Keypad=

[[Payphone/Implementation]]

==2023 Phone Rebuild for Capp St==
After some time, the 2021 reprise began to fail due to water intrusion. This resulted in the keypad entry system being taken out of service.

The keypad was rebuilt and a RJ45 jack added within the phone case to connect the keyboard matrix to an external system.

On the secure side of the wall, a circuit was built to read the keypad and control the strike.

The circuit consists of protoboard with a socket for a NodeMCU, a header that a RJ45 jack is attached to (to connect to the keypad), a 5v regulator, a transistor for driving the door strike, and screw terminals for the 12v input and door strike output.

The current design does not allow for easy use of the hang up switch or the phone receiver. It has been proposed that any projects involving these parts be kept on a separate circuit from the access control system.

==2021 Phone Reprise for Door Entry System to New Capp St Space==
After the move in 2020, and maybe even before? The phone had been unused. It was decided to try add VoIP back to the phone, but after a mishap with the keyboard, the phone was set aside.

However, the new space was in need of a door access system for the outer door, since a gate pad lock had been used for months. 

A keyboard entry system was created by Woz, in which a keyboard ran to a raspberry Pi to then activate the door strike (latch).

With that in place, Jaguar decided to turn the phone into a simple keyboard to replace the computer keyboard which was then outside the gate. Jaguar donated a Teensy for this and created a new keypad that sits underneath the metal keypad.

The keypad uses a row and column type soldering and pinout. 

With this in mind Woz came up with the idea to keep all the rows low, and the columns high, then to set the column to low on keypress. This would allow code to capture the exact key pressed as follows:

  void loop(){
    digitalWrite(rowPin0, LOW);
    digitalWrite(rowPin1, HIGH);
    digitalWrite(rowPin2, HIGH);
    digitalWrite(rowPin3, HIGH);
    if (digitalRead(columnPin0) == LOW){
      Keyboard.set_key1(KEY_1);
    } else {
      Keyboard.set_key1(0);
    }
    Keyboard.send_now();


While this worked with the keyboard, a later problem occurred where the Raspberry Pi got damaged.
So new code was written to control the door directly from the Teensy. 
Please see the [https://github.com/masparasol/payphone-keyboard github repo] for the latest version.

Currently (~Dec 2021) the phone lives in this state with a custom keyboard and the teensy chip (which runs on arduino software). 
It can now be hacked to play music, or use the ear piece of the phone, and various other ideas for the phone.
Contact Paul_H on the slack/discord/discuss with questions. :)


[https://raw.githubusercontent.com/masparasol/payphone-keyboard/main/run-keyboard-to-digital-pwm.jpg Photo of keyboard wiring to Teensy]

[https://raw.githubusercontent.com/masparasol/payphone-keyboard/main/keypad-wire-to-strike-and-power.jpg Photo of keyboard wired to power and door strike(latch)]

[https://raw.githubusercontent.com/masparasol/payphone-keyboard/main/legacy-power-conversion-to-activate-strike.jpg Electronics to power strike and teensy chip]

[https://raw.githubusercontent.com/masparasol/payphone-keyboard/main/phone-hanging-outside-gate.jpg Phone outside the gate.]

=The History of Project Payphone=

The payphone's number is not available as of this edit

==The Idea==

[[Image:Noisebridge_RedPayPhone1.png| Red Payphone graphic, circa 2011]]
[[Image:Noisebridge_RedPayPhone2.png| Red Payphone dialplan, circa 2011]]

While it looks the same circa 2016, the functionality is much different. The stuff like "leave a message" and "dictate to IRC" aren't really relevant so much. Though it would be pretty cool to "leave a message to be dictated to [[Slack|groupchat]]".

Another idea is to make an Intercom that allows someone to pick up the phone and speak out of the speakers in Mary Poppins. "toll free nation-wide calls" is hilarious and should remain.

==History of the Phone==

An awesome old red payphone was serendipitously discovered abandoned on Grand Avenue in Oakland. Our local hero picked it up and brought it to the space.

We got it open to discover the following:

*The date of manufacture seems to be a very scribbly Aug. 1988.

*It is completely missing the coin counting and collecting mechanism.

*The keypad and hang-up switch look intact. The metal buttons on the outside actually just press against a standard little plastic keypad on the inside.

*The headset is not connected to anything, but terminates in four red, black, green and yellow wires that can be hooked up to a standard RJ11 (normal phone jack) connector.

*Out of the keypad/hang-up switch part there is a DB15 connector, equally hooked up to nothing. The assumption is that both this and the headset were connected to the coin counting mechanism which was the brains of the operation.

*We'll likely need to gut another phone for some missing parts, but how much surgery is needed will depend on what that DB15 connector can do for us. For that, we need someone to find a schematic for the pins, or someone who is a master reverse-engineer. If that's you, get to work!

https://documents.alicat.com/pinouts/db15.pdf
This help? ^^^

''Well, Seth is a master reverse-engineer, and Steen is an old school phreaker, so one long night spent on this later:''

*We decoded the standard schema for DTMF that seems to apply at least to both the gutted landline phone and the payphone internals, and determined the pinouts for both the relevant bits. It turns out, a button on the keypad doesn't simply close a circuit to make a pin hot, it activates two pins, which then correspond to inputs on the DTMF encoder chip. In other words, Dual-Tone doesn't just mean the tones that are output, it also applies to the signals inside the phone circutry. Neat! So now we can connect the output pins from the payphone keypad to the DTMF inputs on the landline guts. Seth is (I think) planning on bringing in a db15 breakout box in order to manifest this. Please no one break it further before we get a chance to do so.

*We figured out the order of wires for the headset to operate, corresponding to the (somewhat arbitrary) aligator clip => rj11 cable we made for the purpose. We got this to connect to the guts of a functioning landline phone, and got a dialtone from the VoIP box, as well as a functioning mic. This mapping is complicated to format on the wiki, it's written on the inside of the old headset in sharpie. That counts as documentation.

==TDM Hardware==

The phone cable is connected to a [https://www.digium.com/products/telephony-cards/analog/4-port Wildcard TDM410P] in [[Pegasus]] which runs inside [[Freeswitch]] with some [https://freeswitch.org/confluence/display/FREESWITCH/FreeTDM software drivers].




==Legacy Photos==

I actually took more pictures but I strangely had a "Memory Card Error" (GRR!) and these were the two I recovered.

Post more if you got 'em.

Legacy Photo ~2008

[[Image:Opening_payphone.JPG|500px]]

Legacy Photo ~2008

[[Image:Opened_payphone.jpg|500px]]

http://flickr.com/photos/pvck/3101832241/in/photostream/

[[Category:Pages with a Noisebridge Tiny URL]]

=Other Payphones=
==Nortel Millennium==
There is a Nortel Millennium phone with red plastic and "The Ohio State University" branding in the space. According to my preliminary research there isn't a way to program this thing without paying a lot of money to the successor to Nortel, which is a shame, since it has quite a bit of neat hardware including a text capable display and a mag stripe and chip card reader. It would be really neat to make this thing accept donations. There is some info that would be useful for someone making an attempt at reverse engineering this thing available here: http://www.binrev.com/forums/index.php?/topic/44015-millennium-manager-application/ and the installation/maintenance manual is here: http://payphone411.com/proteldocuments/nortel_millennium.pdf