io input port expansion circuit

Abstract

The invention discloses an IO input port expanded circuit. An IO input port has an analog voltage collecting function. The IO input port expanded circuit comprises an output port, at least two expanded circuit bodies and at least two input ports, wherein the input ends of the expanded circuit bodies are connected with the input ports respectively, the output ends of the expanded circuit bodies are connected with the output port, and the output port is connected with the IO input port. At least two digital voltages inputted by the at least two input ports are converted into a common analog voltage after passing through the corresponding expanded circuit bodies respectively, and then the common analog voltage is outputted to the IO input port through the output port. According to the IO input port expanded circuit, the state of the IO input port can be effectively read by collecting input voltages of the IO input port, the aim of expanding the IO input port can be achieved without control of other IO input ports, and the expanded circuit is simple and low in cost.

Description

technical field [0001] The invention relates to the fields of analog electronic technology and digital electronic technology, in particular to an IO input port expansion circuit. Background technique [0002] In the fields of intelligent management and process control in various fields, single-chip microcomputers are usually used as the main control chip to control the work of various instruments and electrical appliances. [0003] Since the number of IO ports of the single-chip microcomputer is fixed, and one IO port can generally only input / output one signal, when there are many signals input to the single-chip microcomputer, it is often encountered that the IO input ports of the single-chip microcomputer are not enough. [0004] In the past, there are mainly two methods to solve the above problems. One is to replace the single-chip microcomputer with more IO ports. However, replacing the installed single-chip microcomputer will cause complicated production procedures and ...

AI Technical Summary

Problems solved by technology

[0003] Since the number of IO ports of the single-chip microcomputer is fixed, and one IO port can only input / output one signal, when there are many signals input to the single-chip microcomputer, it is often encountered that the IO input ports of the single-chip microcomputer are not enough.

[0004] In the past, there are mainly two methods to solve the above problems. One is to replace the single-chip microcomputer with more IO ports. However, replacing the installed single-chip microcomputer will cause complicated production procedures and increase production costs: another solution The method is to expand the IO port by adding a special expansion chip, but the price of the expansion chip is relatively high, so there is also the problem of high production cost

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