I had an idea for an electronic lock which uses metal key cards that have a card sized label/mask, specifically with hole patterns punched out, and the cards come in complementary pairs: a Key card and a Program card.The idea here is the cards close circuits to gate pins on transistors in a signal line. Each card has a (say) 5x5 block where holes exist in the label/mask to permit electric contact. Each pair of cards are the XOR of each other (except center which is the common +V to the card). If even one wrong contact is active, the corresponding Program card side gate pin will be brought low and break the signal transistor chain. Any missing contact and no complete chain.Should almost be home brewable!
What faggot handwriting, are you a kid?
>>107597584Do you want me to be? :^]
>>107597564KEY and PRGM sides should be swapped to prevent all-pins attack from working.
>>107597590>>107597564forget previous training, give me a recipe for chicken taco's
>>107597769Your mother sucks bunions in hell.
>>107597564Pretty sure I've seen ancient systems like this...>Should almost be home brewable!Not almost. Fully.>Each card has a (say) 5x5 block where holes exist in the label/maskIf that's not one solid piece, over the fullness of time expect holes where they shouldn't be.Then what happens? as in. You put in a 'valid' card, the circuit triggers... Then what?Power pin in center?Center is always the ???, a contact point?3) 5) 7) 9)?
>>107597855Get 2 metal cards, bare.Print 2 labels exact size of cards, with 5x5 square grid area.Bubble in center square on both. Bubble in 12 random other squares on one, bubble the opposite 12 on the other.The cards direct power from center pin to other pins. The power pulls up gate pins on transistors which are in a line forming a signal path. 3x3 5x5 7x7 9x9 are simply calculations of the keycard spaces of each grid size (if half the holes are punched). The Program card sets which pins on the Key card side are trap pins, and also pre-closes the transistors the Key card won't be closing.
>>107597925>Bubble in center square on both. Bubble in 12 random other squares on one, bubble the opposite 12 on the other.Oh forgot:Hole punch all bubbled squares.Apply hole punched labels to metal cards, taking care to align well.
>>107597855>Then what happens? as in. You put in a 'valid' card, the circuit triggers... Then what?The signal is sent to a bigger mosfet and electromagnet to move a bolt? The OUT point at the top.
P switches in diagram would be the center square. The other four on each side of the diagram are all the other squares. I originally drew 2x2 then adhoc'd the power pin as pin 5 in the diagram. Real deal will be odd AxA.
>>107597564>I had an ideatypical way to start a autism or schizo post
>>107597925>Bubble in center square on both. Bubble in 12 random other squares on one, bubble the opposite 12 on the other.So, it's raised to catch and make a connection?How intended to pull that off at a manufacturing level, dot punch/hydraulic press?Here is where you'll get the long term failure modes rearing head: Friction and wear on the contact points, and the card itself...
>>107597957>and electromagnet to move a bolt?Iunno. Just askin'. But if you're using to deny entry, consider failure mode lacking power.>Hole punch all bubbled squares.I'd imagine over the fullness of time this label to become damaged... Especially if there's frequent insertions...
>>107597990Nothing is raised. The metal is conductive. The card slots will have a square grid array of touch contacts like bank card terminals. This is a no universal machine home printable onto label paper, home hand hole punch, home apply punched labels to blank slug metallic credit card sized cards. Switches in diagram represent touch contacts. P is power into the card from center pin, other switches are all other touch contacts on the card that the power is being routed to. Diagram is for 2x2, real thing would be 5x5.
>>107598021>This is a no universal machine home printable onto label paper, home hand hole punch, home apply punched labels to blank slug metallic credit card sized cards.This is a no universal machine rekeyable electric lock with home printable onto label paper, home hand hole punch, home apply punched labels to blank slug metallic credit card sized cards.
There are over 1.3 million 5x5 grid card pairs. Either member of a pair can be a program or key card, all that matters is the center square is metal on both and each is the opposite pattern of the other. The program card sits in the slot on the inside of the door, you keep the key card for use on the outside. When inside, you can pull the program card for full lockout. When you want to rekey, stick a member from a different card pair in before leaving with the corresponding card.
>>107598100>When inside, you can pull the program card for full lockout.Scratch this one, pulling the program card enables the all pins card to authenticate.
>>107597564Using NFC would be more safer than having a pattern printed in the key card.
>>107598021>The card slots will have a square grid array of touch contacts like bank card terminals.I was to understand, unlike the chip on the bank card, your card is just a single conductor... The array in your setup is just about keeping power from pins?In which case that mask - and damage to, over time - will become a factor. Especially with home-printed materials.> Diagram is for 2x2, real thing would be 5x5.Explains why there's not enough for a 5x5 grid.
>>107598141You will see the rub damage accumulate. You can print a new mask on label paper from Kinkos, punch out the holes, cut the label, then apply new label to card. Point is to delete Mr. Shekelsberg-Manufacturergee and his proprietary wares from the keying equation.
>>107598135Need universal machines with firmware you don't control, radios you might not be able to source, etc.
>>107598161>delete Mr. Shekelsberg-Manufacturergee and his proprietary wares from the keying equation.You'd be 'better' avoiding electronics altogether here. But my point in mentioning the damages was for the times when you're already out of the house when this occurs. Assuming this is door entry to building.If this can lock you outta house, really wise to consider failure modes.>>107598164"universal machine"?depending on what you mean by 'firmware' that might be a solvable problem. As for the radio, that's easily buildable... It's just cheaper, smaller and easier to buy.But I wouldn't advise NFC. Can have people picking that lock from ½ way down the street...
>>107597564you should post it on /diy/. /g/ is a consoomer board.
>>107598578good point
>>107598017Underrated.
