Introduction: The Keyless Bike Lock

One thing many people don’t know is that it is much easier to pick bike locks than it seems. That is why our team is proposing our design for a RFID enabled bicycle U-lock. Instead of using an antiquated mechanical lock, users can simply hold a unique RFID tag or chip of their choosing (including UT ID cards) to the surface of the device to unlock it – an entirely keyless solution. Any

five-volt cell phone charger can charge the proposed device. With that in mind, our team estimates that the lock can be used at least 500 times before needing to be recharged – power should not be an issue.

Step 1: Materials


Pro Mini Arduino 5v (16MHz) ($6.49 each)

USB FTDI Breakout for Pro Mini ($9.95 each)

Micro solenoid x1 ($3.36 each)

Kryptonite 4" x 9" U-LOCK

TIP120 Power Transistor x1 ($2.50 for pack of 3)

Fairchild Diode ($3.65 for pack of 5)

Powerboost 1000C charging module x1 ($19.95)

SparkFun RFID Reader breakout x1 ($1.95 each)

ID-12LA RFID Reader chip x1 ($29.95 each)

3.7v 2200mAh Li-Ion battery x1 ($9.95 each)

Small Waterproof push button ($8.99 for pack of 10)


Step 2: 3D Print Parts

Print both of these files in ABS, higher quality prints.

Step 3: Make Arduino Low Power

Follow "madcoffee's" instructions on making Arduino Pro Minis low power. Remember that we are using he 5v model:

Step 4: Put Together Circuit

Follow the circuit schematic to put together the device.

Step 5: Install Solenoid

Bolt the solenoid down to base

Step 6: Finish

Insert the 3D printed base into the printed shell, insert a U-bar, and test!