Forehead thermometer displaying different colors according to detected temperatures and control circuit thereof

A control circuit for a forehead thermometer control circuit that displays different colors according to detected temperatures, wherein:

• the control circuit comprises a single-chip microcomputer main control and interface circuit, a liquid crystal displaying and driving circuit, a sensors and amplifying circuit, a lithium battery charging and charging wake-up circuit, and a power supply voltage regulating circuit;
• the single-chip microcomputer main control and interface circuit comprises a SCM chip, and the model of the SCM chip is PIC16LF1938-I-SS;
• the liquid crystal displaying and driving circuit comprises an LCD screen and a liquid crystal dot matrix display driving chip, and the model of the liquid crystal dot matrix display driving chip is HT1621B-48;
• the No. 15 pin, No. 16 pin, No. 17 pin, and No. 18 pin of the single-chip microcomputer are respectively connected with the No. 9 pin, No. 10 pin, No. 11 pin and No. 12 pin of the liquid crystal dot matrix display driving chip;
• the No. 1 pin to No. 8 pin of the liquid crystal dot matrix display driving chip are respectively connected with the No. 8 pin to No. 1 pin of the LCD screen;
• the No. 21 pin to No. 24 pin of the liquid crystal dot matrix display driving chip are respectively connected with the No. 13 pin to No. 16 pin of the LCD screen;
• the No. 45 pin to No. 48 pin of the liquid crystal dot matrix display driving chip are respectively connected with the No. 12 pin to No. 9 pin of the LCD screen;
• the LCD screen also comprises a backlight board which is driven by a backlight plug-in 1;
• the No. 2 terminal of the backlight plug-in 1 is connected with the No. 25 terminal of the single-chip microcomputer, the No. 3 terminal of the backlight plug-in 1 is connected with the No. 26 terminal of the single-chip microcomputer, and the No. 4 terminal of the backlight plug-in 1 is connected with the No. 23 terminal of the single-chip microcomputer;
• the sensors and amplifying circuit comprises an infrared receiver IR1, a thermopile sensor, and a zero-drift operational amplifier TP5552;
• the infrared receiver IR1 is connected with the No. 2 pin of the single-chip microcomputer, the GND terminal of the thermopile sensor is connected with the No. 3 pin of the single-chip microcomputer after rectification and filtration, the TP+ and TP− terminals of the thermopile sensor are respectively connected with the No. 3 pin and No. 2 pin of the zero-drift operational amplifier TP5552 after rectification and filtration, and the No. 1 pin of the zero-drift operational amplifier TP5552 is connected in parallel with the No. 2 pin of the single-chip microcontroller after rectification and filtration;
• and
• the No. 28 pin of the single-chip microcontroller is also connected with a power supply on/off key S1, the No. 22 pin of the single chip microcomputer is also connected with a temperature Celsius/Fahrenheit switch key S2, and the No. 23 pin of the single-chip microcomputer is also connected with a detection execution key S3.