code cleanup

matrix_keyboard.cpp

@@ -0,0 +1,56 @@
+#include <Arduino.h>
+#include <iterator>
+#include "esp32-hal-gpio.h"
+/*
+ * AES256 Seed Phrase Encryptor
+ *
+ * Copyright (C) 2026 SCHAUAUS GmbH
+ *
+*/
+
+// pin definitions
+#define KEYBOARD_COL1_PIN 1
+#define KEYBOARD_COL2_PIN 2
+#define KEYBOARD_COL3_PIN 3
+#define KEYBOARD_COL4_PIN 0
+#define KEYBOARD_COL5_PIN 5
+
+#define KEYBOARD_ROW1_PIN 18
+#define KEYBOARD_ROW2_PIN 19
+#define KEYBOARD_ROW3_PIN 20
+#define KEYBOARD_ROW4_PIN 23
+
+// project includes
+#include "matrix_keyboard.h"
+
+char keyboardCharacters[] = "0123456789ABCDEF<OX>";
+int colPins[] = { KEYBOARD_COL1_PIN, KEYBOARD_COL2_PIN, KEYBOARD_COL3_PIN, KEYBOARD_COL4_PIN };
+int rowPins[] = { KEYBOARD_ROW1_PIN, KEYBOARD_ROW2_PIN, KEYBOARD_ROW3_PIN, KEYBOARD_ROW4_PIN };
+
+void initKeyboard () {
+  // set column pins as input pulled low
+  for ( int i = 0; i < sizeof(colPins) / sizeof(colPins[0]); i++ )
+    pinMode(colPins[i], INPUT_PULLDOWN);
+
+  //set row pins as output
+  for ( int j = 0; j < sizeof(rowPins) / sizeof(rowPins[0]); j++ ) {
+    pinMode(rowPins[j], OUTPUT);
+    digitalWrite(rowPins[j], 0);
+  }
+}
+
+char readKeyboard () {
+  for ( int i = 0; i < sizeof(rowPins) / sizeof(rowPins[0]); i++ ) { // walk through each row of keys on the matrix keyboard
+    digitalWrite(rowPins[i], 1);
+    delay(100);
+    for ( int j = 0; j < sizeof(colPins) / sizeof(colPins[0]); j++ ) { // read each column of the keyboard to identify a pressed key
+      if ( digitalRead( colPins[j] ) ) {     // check if button is pressed
+        while ( digitalRead( colPins[j] ) ); // wait until button is released again
+        digitalWrite(rowPins[i], 0);
+        return keyboardCharacters[i*4 + j];  // return key
+      }
+    }
+    digitalWrite(rowPins[i], 0);
+  }
+  return '\0';
+}