Init commit with many years of arduino sketches and projects. I dont know if the esp8266 includes much, but there are also libraries. I hope they dont have crazy automatic versioning through the Arduino IDE.

Projects/libraries/Installed_libs/Keypad/examples/HelloKeypad3/HelloKeypad3.ino

@@ -0,0 +1,68 @@
+#include <Keypad.h>
+
+
+const byte ROWS = 2; // use 4X4 keypad for both instances
+const byte COLS = 2;
+char keys[ROWS][COLS] = {
+  {'1','2'},
+  {'3','4'}
+};
+byte rowPins[ROWS] = {5, 4}; //connect to the row pinouts of the keypad
+byte colPins[COLS] = {7, 6}; //connect to the column pinouts of the keypad
+Keypad kpd( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
+
+
+const byte ROWSR = 2;
+const byte COLSR = 2;
+char keysR[ROWSR][COLSR] = {
+  {'a','b'},
+  {'c','d'}
+};
+byte rowPinsR[ROWSR] = {3, 2}; //connect to the row pinouts of the keypad
+byte colPinsR[COLSR] = {7, 6}; //connect to the column pinouts of the keypad
+Keypad kpdR( makeKeymap(keysR), rowPinsR, colPinsR, ROWSR, COLSR );
+
+
+const byte ROWSUR = 4;
+const byte COLSUR = 1;
+char keysUR[ROWSUR][COLSUR] = {
+  {'M'},
+  {'A'},
+  {'R'},
+  {'K'}
+};
+// Digitran keypad, bit numbers of PCF8574 i/o port
+byte rowPinsUR[ROWSUR] = {5, 4, 3, 2}; //connect to the row pinouts of the keypad
+byte colPinsUR[COLSUR] = {8}; //connect to the column pinouts of the keypad
+
+Keypad kpdUR( makeKeymap(keysUR), rowPinsUR, colPinsUR, ROWSUR, COLSUR );
+
+
+void setup(){
+//  Wire.begin( );
+  kpdUR.begin( makeKeymap(keysUR) );
+  kpdR.begin( makeKeymap(keysR) );
+  kpd.begin( makeKeymap(keys) );
+  Serial.begin(9600);
+  Serial.println( "start" );
+}
+
+//byte alternate = false;
+char key, keyR, keyUR;
+void loop(){
+
+//  alternate = !alternate;
+  key = kpd.getKey( );
+  keyUR = kpdUR.getKey( );
+  keyR = kpdR.getKey( );
+
+  if (key){
+    Serial.println(key);
+  }
+  if( keyR ) {
+    Serial.println( keyR );
+  }
+  if( keyUR ) {
+    Serial.println( keyUR );
+  }
+}