51 Microcontroller Desktop Temperature Clock Development Board

Project Introduction:
This project is a desktop temperature clock development board based on the STC89C52RC, featuring humidity detection and time display functions. It can be used as a course design and practice project for microcontroller courses. The development board uses a 0805 package for easy use and rapid soldering on a heating table.
Project Functionality:
This humidity clock development board is based on the STC89C51/52 microcontroller. The front has three independently programmable buttons, and the back has a matrix button and running lights. It uses a 0.36-inch common cathode white digital tube driven by an SN74HC595PWR, providing good display quality.
Project Parameters:

This design uses an LCD1602 liquid crystal display, with the top row displaying the current date and time.
It selects a DS18B20 humidity sensor; the driver code is simple, and the driver circuit is easy to understand, making it suitable for beginners. This should meet general needs. For

soldering
, a heating table is recommended. Use 138°C low-temperature solder and maintain a constant temperature of 170°C on the heating table.
When soldering the Type-C port with a soldering iron, apply solder paste first, and then use a wooden toothpick to apply solder balls to the pads while the device is heated. After cleaning the pads, install the components.
Design flaws:
Hardware:
1. Lithium-ion battery charging chips and voltage regulator chips should be used to greatly extend battery life
. 2. To control costs, this project did not include a power-off timing battery like the DS1302
. 3. This project uses too many vias in the circuit connections.
Software:
1. This project's software does not use a timer; delay relies entirely on for loops, blocking MCU time
. 2. It is recommended to add three independent buttons to control the time
(very important). The MCU's TXD and RXD should be connected to the CH340 module using flying wires, written into the download file in the example code, and called in the main function to enable hot-start download.