Alcoholímetro (Breathalyser)

thingiverse

Human: STL files have been printed with a Core XY printer. The MQ3 alcohol sensor nozzle is disposable. There are two files for the nozzle, but only one should be printed. If you want the nozzle to rotate, print the MQ3 case.stl file, but if you want the nozzle to insert at pressure, print the MQ3 caseWithoutRotation.stl file. Either of them must be printed with support. On the exterior casing, use support and I recommend a speed of 60. On all other STL files, I used a speed of 40 because I wanted good printing quality. Components and PCBs: -Arduino Uno board -MQ3 alcohol sensor -10mm green and red LEDs -Buzzer -I2C LCD screen -Small protoboard (important if you don't want to solder) -Jumper cables -Disposable nozzles. I used this model: https://www.aliexpress.com/item/100pcs-Digital-Breath-Alcohol-Tester-Breathalyzer-Mouthpieces-Blowing-Nozzle-for-Keychain-Alcohol-Tester-Mouthpieces-for-68s/32817985816.html The main problem with this project is calibrating the MQ3 sensor. It's not easy because it requires laboratory conditions. That's why I recommend calibrating it with a hydrometer.