The mail slot detector uses a type of sensor called a break beam sensor. It is made of two parts, an emitter and a sensor. When the sensor has a clear line of sign to the emitter, everything is fine, when the beam is broken, it'll trigger the code to send an alert.
The emitter is an infrared (IR) LED that is always on. It has a black wire and a red wire that connect to ground and power, respectively.
The sensor has three wires for ground, power, and signal.
Connect to FunHouse
To connect the break beam sensor to the FunHouse you'll use a couple of JST-PH cables.
You can plug them in directly as shown above, simply match the colors of each wire.
For a more secure fit, a piece of heat shrink tubing is helpful. Add a bit to each bundle for wire management, and a larger piece to secure the connections.
Note one white wire will remain unused.
Use double-stick tape to secure the sensors inside the mailbox. Uglu Dashes work great for this.
Secure to Mailslot
This step can vary a lot depending on the type of mail slot you have.
Use the adhesive to affix the sensor and the IR emitter so that their beam will be broken when mail enters the slot.