Simple keyboard with numbers.
The keyboard has numbers from 0 to 9 and the signs * and #. The buttons are connected in a matrix, due to the fact that for the detection of 12 buttons, you need only 7 pins of the microcontroller. Keyboard is sold in white and black.
The matrix consists of 10 buttons such as a tact switch, arranged in two rows and five columns. The Board also contains a joystick. The module communicates via a 5-bit interface displayed on the 7 popular goldpin connection raster of 2.54 mm.