commit 6da8d10f8419214ac53ddb83a08268800d36ecb2
Author: Reinout Meliesie <zedfrigg@kernelmaft.com>
Date:   Sat Aug 23 19:05:48 2025 +0200

    Initial serial-controlled version that works with Arduino IDE

diff --git a/kulifuli-arduino.ino b/kulifuli-arduino.ino
new file mode 100644
index 0000000..a87d8a6
--- /dev/null
+++ b/kulifuli-arduino.ino
@@ -0,0 +1,84 @@
+bool fanControlEntered = 0 ;
+
+
+void setup () {
+  Serial . begin (9600) ;
+
+
+  // 122Hz @ 50% on pin 3 using T/C0
+
+  pinMode ( 3 , OUTPUT ) ;  // 0C0B is connected to pin 3
+
+  TCCR0A =
+    0 << COM0A1 |
+    0 << COM0A0 |
+    1 << COM0B1 |
+    0 << COM0B0 |
+    1 << WGM01 |
+    1 << WGM00 ;
+
+  TCCR0B =
+    1 << WGM02 |
+    1 << CS02 |
+    0 << CS01 |
+    1 << CS00 ;
+
+  OCR0A = 127 ;
+  OCR0B = 63 ;
+
+
+  // 25kHz @ variable duty cycle on pins 9 and 10 using T/C1
+
+  pinMode ( 9 , OUTPUT ) ;  // 0C1A is connected to pin 9
+  pinMode ( 10 , OUTPUT ) ;  // 0C1B is connected to pin 10
+
+  TCCR1A =
+    1 << COM1A1 |
+    0 << COM1A0 |
+    1 << COM1B1 |
+    0 << COM1B0 |
+    0 << COM1C1 |
+    0 << COM1C0 |
+    1 << WGM11 |
+    0 << WGM10 ;
+
+  TCCR1B =
+    1 << WGM13 |
+    1 << WGM12 |
+    0 << CS12 |
+    1 << CS11 |
+    0 << CS10 ;
+
+  ICR1H = 0 ;
+  ICR1L = 79 ;
+
+  OCR1AH = 0 ;
+  OCR1AL = 39 ;
+  OCR1BH = 0 ;
+  OCR1BL = 39 ;
+}
+
+
+void loop () {
+  if ( Serial . available () ) {
+    if (fanControlEntered) {
+      int dutyCyclePercent = Serial . parseInt () ;
+      int dutyCycle = map ( dutyCyclePercent , 0 , 100 , 0 , 79 ) ;
+      OCR1AL = dutyCycle ;
+      OCR1BL = dutyCycle ;
+      Serial . read () ;  // Consume newline
+
+      Serial . print ("duty-cycle ") ;
+      Serial . print (dutyCycle) ;
+      Serial . print ('\n') ;
+    } else {
+      String input = Serial . readString () ;
+      if ( input == "enter-fan-control" ) {
+        fanControlEntered = 1 ;
+        Serial . println ("success") ;
+      } else {
+        Serial . println ("error") ;
+      }
+    }
+  }
+}