Alcohol meter based on MQ-3

Foreword:
       In recent years, as people's awareness of the dangers of drunk driving has increased, the demand for alcohol testing of ordinary drivers has grown strongly. Therefore, portable breathalyzers have gradually entered the lives of the general public. This application designs a low-cost portable breath alcohol detector, using the semiconductor alcohol test sensor MQ-3 and an MCU with LCD driver (R7F0C002) as the hardware core.
Functional summary (see design description for details):
Using Renesas' low-power MCU R7F0C002, this MCU achieves high processing performance with the lowest power consumption among similar products, and also has a built-in liquid crystal display (LCD) driver.
4-digit universal LCD panel displays measurement results in real time.
The semiconductor alcohol measurement sensor MQ-3 is used, which has the characteristics of good sensitivity, low cost and long life.
It has a buzzer alarm function and will automatically alarm when the measurement result exceeds the alcohol concentration standard for drinking and driving.
Hardware structure block diagram:
Main technical parameters:
Test range: 0.00 ~ 200 mg/100ml
Display range: 0.00 ~ 99.99 mg/100ml
Preheating time: 20 seconds
Measurement time: 5 seconds
Repeat test: Within 30 seconds
Display value: LCD 4 digits Display
battery power supply: 6LR61 9V alkaline battery
 Battery standard test usage: 100 times