On-campus tryout: simple thermometer based on thermistor

      This production uses an NTC thermistor to sense the external temperature, and is equipped with a 431 classic voltage stabilizing circuit, a Wheatstone bridge voltage divider, and an op amp proportional amplification as its peripheral circuit to control the temperature drift at about 5%. There is also an OLED display module to display the temperature, and a new humidity sensing measurement module. This production is mainly controlled by Arduino UNO and can be used as an expansion board.

This design won the first prize in the founding competition of Shanghai University of Applied Technology

Physical map:

Thoughts:

This circuit design is still quite challenging for me. Although there are many versions of the overall idea from the beginning of the topic selection, there is no real practical production experience, and the focus of this design is on the thermistor peripheral circuit. Therefore, there are still many uncertain factors in the actual process from circuit type selection to capacitance and resistance value determination. Although this experiment is only a competition question, its scope is very wide, and I have experienced from the most original design process to the current version one update to the current simple and good presentation temperature. Show version. Each of these versions requires an understanding of its principles and ideas in order to design a better circuit. However, in actual operation, if a change in principle is made, the PCB circuit diagram will inevitably need to be redrawn, and those that seem to have extremely simple wiring The PCB diagram is actually the most time-consuming to complete. But it is undeniable that in the design revisions one after another, I have done more experiments than others and learned more diverse circuit design knowledge. In redrawing PCBs and schematics again and again, I gain more practical experience than others, so that I can become more familiar with Lichuang EDA software.