51 Minimum Development Board | V1.0

The STC89C52RC-40I-LQFP44 is a minimum system board with Type-C power input, no CH340, and serial port download.
P1.0-P1.2 are LEDs, and P2.0 and P2.1 are independent buttons in the upper right corner. It integrates a 5V to 3.3V converter. The attachment includes an LED movement and blinking test program.
Chip selection: STC89C52RC-40I-LQFP44.

The STC89C52RC is a high-performance microcontroller based on the 8051 core, featuring rich I/O ports, timers, serial ports, and interrupt functions, suitable for various embedded applications.
The LQFP44 package offers more pins, facilitating peripheral expansion and making it suitable for more complex application scenarios.
System board design features:


Power input: Uses a Type-C interface for power input, supporting efficient and stable power supply to ensure the normal operation of the microcontroller and peripheral circuits.


Reset circuit: Includes a reset circuit to ensure the microcontroller is correctly initialized upon power-on or reset.


Crystal oscillator circuit: A suitable crystal oscillator circuit is configured to provide a stable clock signal for the microcontroller, ensuring its normal operation.


Download interface: Since the CH340 is not used for serial communication and downloading, this design directly utilizes the microcontroller's serial port downloading function, programming via a standard serial port.



Test program:
#include
#include   
 
void delay(unsigned int i)
{
unsigned int j;
unsigned char k;
for(j=i;j>0;j--)
for(k=125;k>0;k--);
}
 
void main()
{ P1=0xfe;
while(1)
{
P1=_crol_(P1,1); //P1 gradually shifts left by one bit.
delay(500);
 
}
}