Home Security System

The PCB
Back side silkscreen

Inspiration

We wanted to build a compact and portable security system with some fun alarm tune options.

What it does

Rings an auditory alarm on each device when any of the devices detect that their window/door has been opened while the alarm is armed. In addition, we send an SMS alert to the phone number on record.

How we built it

We decided on the sensor and actuator for the device which would be a reed switch and a speaker resp. Then to reduce the size of the device, compact placement of the components on the PCB was necessary when it was designed. The firmware was written to include over the air firmware updates.

Challenges we ran into

The I2S module on the microcontroller was present but non-functional which we found out later in the errata

Accomplishments that we're proud of

We managed to play sound in the project using PWM because the microcontroller does not have a functional I2S module in it. We also allowed the user to change the alarm song remotely from their cloud interface.

What we learned

It is important to check the specifications of the project before starting the design and checking if the microcontroller can support the functionality required by the application. Attention to detail is important. Something as minor as an LED affects the user experience