Add clock sketch

Author: Andy4495

src/variable_clock_generator/variable_clock_generator.ino

@@ -0,0 +1,30 @@
+/* -----------------------------------------------------------------
+    Clock generator sketch for use with my Homemade CPU
+
+    https://github.com/Andy4495/Homemade-CPU
+
+    25-Oct-2025 Andy4495  Original
+
+*/
+
+
+unsigned int freq = 50;
+
+void setup() {
+  pinMode(3, OUTPUT);
+  Serial.begin(9600);
+  Serial.println("Initial frequency: 50");
+  tone(3, freq);
+}
+
+void loop() {
+  if (Serial.available()) {
+    freq = Serial.parseInt();
+    if (freq != 0) {
+      Serial.print("New frequency: ");
+      Serial.println(freq);
+      tone(3, freq);
+      Serial.println("Enter frequency: ");
+    }
+  }
+}