Design Process
The concept is simple a sensor that detects the amount of alcohol particles in the air takes in a reading when the red button is pressed. The user then blows into the tube. After the reading has commenced the display outputs the result of the user's BAC (not actual BAC for legal purposes). If the sensor detects over a specific threshold a timer will be displayed, at the end of the countdown the connected light source will be shut off. If the sensor does not pick up any alcohol then the light will turn on and remain on. The user can turn the light off at any moment by pressing the black button.
The design process included designing the circuit in which the sensors, buttons, display, and relay controlling the light would receive wall power and commands from an Arduino Uno. Simultaneously code was being developed in Arduino IDE to take in the readings from the sensors and the button states, these readings were used to decide the output on the display and the state of the relay. Multiple sketches of the enclosure were then designed before the laser cutting process to which the electronics would fit. From there multiple rounds of testing commenced until the project was satisfactory.
To the right is a functional video of the product.
