Mini PCR Instrument - Main Control Board

Note:
This is the main control circuit board of a simple PCR thermal cycler (╹△╹). I tried to DIY a simple PCR thermal cycler. (PCR: Polymerase Chain Reaction)
 
Functions:
1. DC plug input 5V 2A power (can also be powered directly using TYPE-C port 5V 2A, but remember not to plug in both at the same time!);
2. Semiconductor cooling chip interface: "PWM1" (power can be adjusted using PWM method);
3. High-temperature ceramic heating element interface: "PWM2" (power can be adjusted using PWM method);
4. Cooling fan interface: "PWM3" (power can be adjusted using PWM method);
5. NTC thermistor and interface;
6. IIC protocol screen interface;
7. Five-way remote sensing input button (very cool);
8. Mounting hole size adapted to common CPU heatsinks (80mm x 80mm);
9. Super cheap and durable main control chip "STC32G12K128" (24MHZ, 12KB RAM, 128KB ROM, no external crystal oscillator required, ..., purchased from official channels for 3 yuan per chip);
 
Some simple test screens:
Soldering:
 
Functional test:
Acknowledgements:
Thank you JLCPCB for the free sampling, which gave me the courage to try and fail. Thank you~