How does the Matrix Keyboard Works?

author: Echo
In the matrix keypad, the row and column lines are respectively connected to both ends of the key switch, and the row line is connected to +5v through a pull-up resistor.

When no key is pressed, the row line is in the high state.When a key is pressed, the row and column lines will conduct,
At this time, the row line level will be determined by the column line level connected to this row line.

This is the key to identifying whether the matrix key is pressed.However, the row and column lines in the matrix keypad are connected to multiple keys. Whether each key is pressed or not affects the level of the row and column lines where the key is located, and the keys will affect each other.Therefore, the row line and the column line must be properly processed to determine the position of the closed key.

Yuyao Xianglong Communication Industrial Co., Ltd. was established in 2005, located in Yuyao, Ningbo, Zhejiang Province. It is mainly specialized in the production of industrial and military communication telephone handsets, cradles, keypads and related accessories. With14 years’ development, it has 6,000 square meters of production plants and 80 employees now, which has the ability from original production design, molding development, injection molding process, sheet metal punching processing, mechanical secondary processing, assembly and oversea sales. Under the help of 8 experienced R&D engineers, we could customize various non-standard handsets, keypads and cradles for customers quickly.