1. Design requirements and goals
The single-chip formaldehyde concentration alarm is composed of 51 single-chip microcomputer + ZE08-CH2O formaldehyde concentration sensor + LCD1602 liquid crystal display + LED light + button + buzzer.
Specific functions:
1. ZE08-CH2O detects the current formaldehyde concentration value and displays it in real time with LCD1602;
2. The minimum alarm concentration can be set by pressing the button. When the actually measured formaldehyde concentration is greater than the set concentration, the buzzer and LED light will alarm;
3. LED lights display normal working status and alarm status;
4. LCD1602 liquid crystal displays the measured formaldehyde concentration value and the set alarm threshold value.
2. Design plan and ideas
In this design, the function of the single-chip microcomputer is to detect the concentration of formaldehyde and display it on the LCD. When the concentration of formaldehyde exceeds the upper limit set by the user, it will give an alarm.
3. Hardware circuit
