Matrix circuit and scan method

Abstract

The invention discloses a matrix circuit and a scan method. The matrix circuit is used for accurately detecting the state of keys or switches, and comprises a matrix circuit body with N line wires (L1...Ln) and N column wires in cross arrangement, the matrix circuit body is provided with N*N keys (S11...Snn), N is a natural number larger than 0, the matrix circuit further comprises N*N diodes (D11...Dnn), the diodes comprise anodes and cathodes, one end of each line wire and one end of each column wire are respectively provided with an I/O pin, the line wires and the column wires are arranged in a staggered mode to form N*N cross points, one key and one diode are arranged on each cross point, one ends of the keys have access to the I/O pins of the line wires, the other ends of the keys have access to the anodes of the diodes, and the cathodes of the diodes have access to the I/O pins of the column wires. According to the matrix circuit and the scan method, the mutual interference between the keys or the switches can be avoided, the detection carried out when the keys or the switches are simultaneously turned off is supported, meanwhile, power consumption is low in the operating process, and the use of an embedded system is facilitated better.

Description

technical field [0001] The invention relates to the field of computer input devices, in particular to a matrix circuit and a scanning method capable of avoiding mutual interference between keys or switches and having relatively low power consumption. Background technique [0002] Matrix circuits are not only commonly used in human-computer interaction devices such as computers, mobile phones, and PDAs, but also widely used in industrial testing. Its advantage is that a large number of keys or switch states can be detected with very few pins of the microprocessor. [0003] A common N×M matrix keyboard circuit requires (N+M) I / O pins. In the matrix keyboard circuit, N row lines and M column lines are crossed to form N×M matrix cross points, and a button or switch is set at each cross point, and each column line is pulled up to the power supply through a resistance element . Both ends of the button are respectively connected to corresponding row lines and column lines, and e...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to overcome the defects existing in the prior art, and provide a matrix circuit, which has the problem of avoiding easy judgment errors when multiple buttons or switches are closed at the same time, and at the same time reduces the power consumption in the circuit

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