#Knockknock folders code#

If the knock is correct the servo will go to unlock and the LED will go green.įlip the power switch off. (This is Operate mode.) I then enter my knock on the front cover. To do this I use one of the kid's lollipop sticks to briefly depress the lid micro switch (simulated lid closure) while flipping the power switch off then on, causing the servo to go to lock position and the LED to go red. Then the LED blinks to verify data store.īefore locking the box it is a good idea to test the knock. There is a pause while knock data is stored in Uno EEPROM. Open the lid and perform a secret knock by knocking on the front cover. The lack of LED flashing to show error for early release is deliberate to reduce kid's interest in fiddling.)

#Knockknock folders code#

The 5 second requirement helps to avoid unwanted Program mode entry due to accidental lid bumps or kid fiddling, and therefore guards against accidental programming and your inability to perform an unknown secret code to open a locked box. (The 5 second lid closure requirement for entry to Program mode is a safeguard against possible lockout. If the lid is released too soon the box will show no LED indication but will accept another closure. Then release the lid and Program mode is ready to receive your secret knock. Press the lid to close it and keep it closed until the LED blinks after 5 seconds. The box will not lock in this mode and will not respond to knocking or lid closures less than 5 seconds (or other value specified), until the lid is held down for more than 5 seconds. This is Program mode, determined by the micro switch in open state. And, if not already unlocked, the servo will go to unlock position. The box will normally be left with lid ajar, held open by the spring action of the lid micro switch.įlip the power switch on. Nominal center tap voltage is 4.5V and that is fed to one of Uno's analog ports, which are scaled to 5V. Battery 9V is attached to one end and ground to the other. The voltage divider has two identical resistors in series. The circuit board has a 9V battery, microphone knock sensor, servo for locking, lid micro switch, resistor voltage divider for battery monitoring, and also carries the power switch and LED. A piece of fabric glued to the false bottom enables easy removal. no screws are required for the cover and false bottom.

The false bottom presses into the box and against the front cover to hold it in place i.e. The front cover slips over the circuit board. The modules interconnect with three ribbon cables. Internally, an Arduino Uno on box bottom and a circuit board on box front are hidden and protected by two covers: a false bottom and a front (circuit board) cover. The box has a power switch and a red/green/blue (RGB) LED on the front.