Cat Weiss Geek House Alcohol Tester

A few days ago, I saw a video explaining the principle of an alcohol tester on the Internet, so I made one. At the beginning, when I was drawing the PCB, I connected the circuit to the pad that it should not be connected to because of my shaking hands during wiring. I didn’t find out until I tested it. Later, I had to cut the circuit with a knife and then connected it with flying wires. However, when testing, I found that several LEDs would light up as soon as the power was connected. I don’t know if the circuit itself is like this or if the chip or sensor was damaged due to the previous error. However, after the alcohol test, it still responded. When the alcohol concentration is high, the LED lights up more, and when the concentration is low, it lights up less. The test result is half successful. The open source circuit has fixed the error, and you can test it again. This project can be used at will. I hope you can open source it intermittently after modification and optimization so that everyone can make progress and learn together.