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JAMMED (Judiciously Applied Materials and Magic Enhanced Doorunlocker) is the device enabling the unlocking of the front doors by electronic identification. Currently equipped with a reader for magnetic stripes. Other Input methods coming soon.



Opening the locked Omni from outside

  1. Approach the double doors (of the Omni) at the S.W. corner of 48th and Shattuck
  2. After using the Identification Method of your choice, the motor will run for for approximately 13 seconds, and a happy sound will play, and perhaps an LED animation in the window.
  3. After 13 seconds of the motor running, grasp the doorknob of the right door and pull BOTH door open. This works even when the original deadbolts are engaged, which is why you don't need a physical key. This arrangement is believed to be wheelchair-accessible.

To LOCK the Omni doors from the outside without using keys

  1. With both doors open, set the two deadbolts to the locked position (protruding)
  2. Carefully align the two doors so that the deadbolts fit into their holes.
  3. Close both doors and gently press on them during the next TWO steps.
  4. Push open the mail slot lid all the way, which activates the locking motor.
  5. Wait 13 seconds for the motor to engage the latches on the left door.
  6. Check to see that the doors are locked and can't be easily pulled open.
  7. If the left door is not secured on either the top or the bottom, unlock and start over.

Operating the door latch from inside the Omni

unlatch button
  • The door on the right (from outside) can be operated normally with the doorknob (if the deadbolts are not locked) if the left door is latched.
  • To latch the left door, put it in the closed position, open the mail slot door fully, and wait 13 seconds for the motor to latch the door.
  • To UN-LATCH the left door, press the button attached to the vertical wooden bar inside the left door (labeled "OPEN")


  • The LED on the magnetic card reader will indicate RED if it fails to read your card. (BART cards can't be read)
  • The green LED on the magnetic card reader will go DARK if it successfully reads your card.
  • The LED on the magnetic card reader will not indicate whether a card is registered or not.
  • An LED strip in the bottom right corner behind the frosted glass of the left Door will indicate motor progress. (In Progress)
  • Audio speaker in a hole in the door to make happy or sad sounds (in progress)

Access Authorization

The individual collectives regulate who is granted Access via this system. Access will be revoked if the safety of the space is compromised independent of the members collective regulations.

Access list editing rights

  • Jake
  • Marc
  • Matt
  • Yar
  • Jenny
  • ...


Have you tried turning it off and on again?

The quick and easy way to return the system to a working state is to reboot everything (assuming nothing is broken). Find the doorjamb computer. It is a laptop hidden under the tiny shelf under the larger shelf on the east wall up agains the big white La Commune counter. On the side of this laptop is the power button. Press it for about a second, then wait for the computer to shut down on its own. If it doesn't shut down after e.g. 20 seconds then press and hold it until it shuts down. After it shuts down, find the big black power brick connected the the door. It's lying on the floor up against the east wall closer to the door. It's a black power brick with one wire going to the arduino mounted on the door and one wire going an extension cord. Unplug where the power brick is plugged into the extension cord, wait a couple of seconds, then plug it back in. Now go to the laptop and press the power button to power it back on. The laptop will take a while to boot. At some point during boot it will speak its IP addresses. A minute or two after it has spoken its IP it should be ready. If it still doesn't work then something more profound is wrong.

Identification Methods

Magnetic Swipe

cardreader in action
  • TL;DR you need a card with a black magnetic stripe on the back, such as a credit card, phone card, gift card, or anything that can be read by our reader. Unfortunately BART cards do not work.
  • The card you want to use must be registered into the system so that it will allow you to open the doors.
  • The card DOES NOT need to have your name on it or be "valid" in any way, it just needs to have something recorded on its magnetic stripe.

How the card data is used

A Hash is created from the already present magnetization pattern on the the stripe. It is hashed using salted SHA1. This means that the information on the cards is not stored anywhere, so if someone steals the computer they will not have access to any private information.

Works with most standard magnetic cards without effecting there normal use. Does not work with 100% of the tested local transit tickets (MTA and BART). However, it is not advised to use Cards which could be harmful to you if the information on the stripes gets in wrong hands (like Government issued IDs or Credit cards). We can not exclude the possibility that Hackers could excess the System storing the Data.[1]

BART cards are so easy to get, why can't we use them?

  • BART cards are not encoded using the bit-pattern standard that our magnetic stripe reader recognizes, and so it can't read them at all. Our reader double-checks every stripe it reads and only reports a reading if it is sure it read the card correctly.
  • In the future, we could replace the card reader with a read-head attached to the microphone jack of the computer, and use a fancy program to read and recognize ANY card people choose to use. Search github for "magnetic stripe"

Detailed Description

Hardware [2]

The upper and lower bolts which keep the left door in place are retracted.


screenshot of doorjam

The software is called DoorJam. It is written in node.js and arduino C and is available here.



  1. As a matter of fact we can guarantee that.
  2. Over 90% recycled materials, approximately 50% natural renewable organic material, 10% re-used buzzwords