On weekends I usually go out with my family and/or friends to some activity, and sometimes we have a few drinks. Some of them usually take their car, and to be a little more relaxed, I designed this device that can indicate the degree of sobriety of a person, just by blowing on the sensor, so they can make the decision of whether to drive or not.

This should not be taken as an absolute test of sobriety, so it should be used with discretion.

Materials

- ATtiny13-20S

- 12mm diameter THT active buzzer

- 1206 104 SMD ceramic capacitor (x2)

- 1206 475 SMD ceramic capacitor

- 2-pin JSP-XH connector

- 5mm THT LED

- 5V mini buster module

- 0.91" 128x32 I2C OLED display

- 3x2 PinHeader for ICSP

- 5x5mm SMD pushbutton

- 5.1 SMD 1206 resistor

- 1K SMD 1206 resistor (x2)

- 10K SMD 1206 resistor

- 47K SMD 1206 resistor

- MQ-3 sensor

- 2N2222 SOT-23 SMD transistor

Features

- Simple and easy to assemble

- Useful for checking if you are sober

- Can be powered by a 3.7V lithium battery

- Easy to program the ATtiny "In-Situ", thanks to the built-in ICSP connector

- Has three holes for mounting (if desired), whose measurements are for metric 2.5 bolts (M2.5)

- 46x47mm PCB

Disclaimer

Hobby use only. Use with caution and at your own risk. We are not responsible, directly or indirectly, for any misuse of the device.

PCBWay Service

Both the circuit and PCB schematics were designed in KiCAD v8. The Gerber was then generated so that it could be sent to PCBWay for manufacturing (like all my boards that I have made). On this occasion, a green PCB with white silkscreen printing was chosen (the classic).

We received the PCBs in just 10 days (to Chile), and as always, the quality was exceptional.

It should be mentioned that during these ten years, PCBWay has distinguished itself by providing exceptional PCB manufacturing and assembly services, becoming a trusted partner for countless engineers and designers around the world.

Its commitment to quality and customer satisfaction has been unwavering, leading to significant growth and expansion.

My advice: check out PCBWay here if you want excellent PCB service at an affordable price, you won't regret it.