From 3f5712ec7a98bb1c280e43f3b2fbd999edf4336c Mon Sep 17 00:00:00 2001
From: Mats van Reenen <mail@matsvanreenen.nl>
Date: Mon, 4 Jan 2021 14:49:16 +0100
Subject: [PATCH] Initial commit

---
 .gitattributes    |  2 ++
 rotoryEncoder.ino | 64 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 .gitattributes
 create mode 100644 rotoryEncoder.ino

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..dfe0770
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,2 @@
+# Auto detect text files and perform LF normalization
+* text=auto
diff --git a/rotoryEncoder.ino b/rotoryEncoder.ino
new file mode 100644
index 0000000..c41baec
--- /dev/null
+++ b/rotoryEncoder.ino
@@ -0,0 +1,64 @@
+#define SENS0_PIN 2
+#define SENS1_PIN 3
+#define ANALOGOUT_PIN 11
+#define HOMESW_PIN 10
+
+#define NUMOFTEATH 360
+#define DEGPERSTAP 3600/(NUMOFTEATH*2)
+
+int16_t angle = 0;
+
+/** setPWM
+ * set the pwm dutycyle
+ * 
+ * @arg value (uint8_t): value for PWM; between 0 - 255
+ */
+void setPWM(uint8_t value){
+  OCR2A = value;
+}
+
+void sens0(){
+  if(digitalRead(SENS0_PIN) != digitalRead(SENS1_PIN)){
+    angle += DEGPERSTAP * 10;
+  }
+}
+void sens1(){
+  if(digitalRead(SENS0_PIN) != digitalRead(SENS1_PIN)){
+    angle -= DEGPERSTAP * 10;
+  }
+}
+
+void setup(){
+  pinMode(HOMESW_PIN, INPUT_PULLUP);
+
+  // setup analog out
+  pinMode(ANALOGOUT_PIN, OUTPUT);
+  TCCR2A = _BV(COM2A1) | _BV(WGM20);
+  TCCR2B = _BV(CS22);
+  setPWM(0);
+
+  // setup rotory sensor
+  pinMode(SENS0_PIN, INPUT);
+  pinMode(SENS1_PIN, INPUT);
+  attachInterrupt(digitalPinToInterrupt(SENS0_PIN), sens0, CHANGE);
+  attachInterrupt(digitalPinToInterrupt(SENS1_PIN), sens1, CHANGE);
+}
+
+void loop(){
+  // delay while checking the home sw
+  for(uint8_t i = 200; i != 0; i--){
+    if(digitalRead(HOMESW_PIN) == LOW){
+      angle = 0;
+    }
+  }
+
+  // wrap angle around
+  if(angle > 3600)
+    angle -= 3600;
+  else if(angle < 0)
+    angle += 3600;
+
+  // update PWM
+  uint16_t a = angle;
+  setPWM(map(a, 0, 360, 0, 255));
+}