Intelligent Motor Speed ​​Counter

CD4511 is a BCD-seven-segment LED latch/decoder/driver. When LE is low,
the data added to the A, B, C, and D terminals are translated into segment drive signals and sent to the segment control line of the digital tube through the current limiting resistor. When LE is high, the drive signal is latched at the output of CD4511 to achieve static display. Since the output of CD4511 is high level effective, a common cathode digital tube is selected. D1 is a working indicator light for debugging.

The debugging of this circuit is divided into two parts: software and hardware. It is recommended to check whether the sensor is working first, which can be seen from the display of D1. LED display requires the help of software. This article is accompanied by a debugging program ts. Asm. Execute the program step by step. If the digital tube does not display 789, then there must be a problem with the hardware. Please check carefully. When you are sure that the hardware is correct, you can enter the main. Asm program. After the simulation debugging is passed, write the program into AT89C51, and the circuit design is completed.

This system can correctly count the motor rotation within the range of 0 to 999 rpm, meeting the needs of production. With a slight modification of the circuit, it can also be expanded to a pulse frequency meter, etc.

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