Description
Description: 1. 4-button Common Cathode key module(When pressed output low level). 2. GND K1 K2 K3 K4" 4 PIN OUT 2.54mm3. Working voltage: DC 0-48V 4. Size: 12.7 x 33mm5. It can be inserted directly into Arduiuo uno3 mega2560 due, for linking up to your Arduiuo uno3 Mini Nano Mega2560 Breadboard for raspberry pi banana pi etc,or others MCU PLD CPU ( AVR STM32 ARM PIC C51 NRF24LE1 CC2530 MSP430 STM8 FPGA CPLD etc.)Circuit schematics:
Arduiuo uno3/mega2560 Code //******************************************************///*Arduiuo_4key_uart
This example code is in the public domain.*/
// Define key pinint K1 = 13;int K2 = 12;int K3 = 11;int K4 = 10;
// variables will change:int buttonState = 0; // variable for reading the pushbutton
// the setup routine runs once when you press reset:void setup() {// initialize the keys pin as an input.
pinMode(K1, INPUT);pinMode(K2, INPUT);pinMode(K3, INPUT);pinMode(K4, INPUT);
//Activate key pin internal pull-up resistorsdigitalWrite(K1, HIGH);digitalWrite(K2, HIGH);digitalWrite(K3, HIGH);digitalWrite(K4, HIGH);
// initialize serial communications at 9600 bps:Serial.begin(9600);}
// the loop routine runs over and over again forever:void loop() {
buttonState = digitalRead(K1);if(!buttonState)Serial.print("k1 n" );do{buttonState = digitalRead(K1);}while(!buttonState);//Wait button release
buttonState = digitalRead(K2);if(!buttonState)Serial.print("k2 n" );do{buttonState = digitalRead(K2);}while(!buttonState);//Wait button release
buttonState = digitalRead(K3);if(!buttonState)Serial.print("k3 n" );do{buttonState = digitalRead(K3);}while(!buttonState);//Wait button release
buttonState = digitalRead(K4);if(!buttonState)Serial.print("k4 n" );do{buttonState = digitalRead(K4);}while(!buttonState);//Wait button release
delay(100);} //******************************************************//
Package Included:
10 x 4 Key MCU Keyboard Matrix Button Board
