Encoder: handle encoder (untested)

firmware/src/encoder.cpp

@@ -14,27 +14,24 @@ When rotated clockwise, CLK changes before DT; when rotated counter-clockwise, D
 
 #define SW_DEBOUNCE_MS 10
 
+bool previousClk = false;
+bool previousDt = false;
+
 void setupEncoder() {
   pinMode(CLK_PIN, INPUT);
   pinMode(DT_PIN, INPUT);
   pinMode(SW_PIN, INPUT_PULLUP);
+
+  // save initial state
+  previousClk = digitalRead(CLK_PIN);
+  previousDt = digitalRead(DT_PIN);
 }
 
 void handleSwitch();
 
 void demoEncoder() {
-  bool clk = digitalRead(CLK_PIN);
-  bool dt = digitalRead(DT_PIN);
-  bool sw = digitalRead(SW_PIN);
-
-  Serial.print("CLK: ");
-  Serial.print(clk);
-  Serial.print(" DT: ");
-  Serial.print(dt);
-  Serial.print(" SW: ");
-  Serial.println(sw);
-
   handleSwitch();
+  handleEncoder();
 }
 
 bool previousPressed = false;
@@ -61,3 +58,33 @@ void handleSwitch() {
   // handle change
   Serial.println(isPressed ? "Pressed" : "Released");
 }
+
+void handleEncoder() {
+  bool clk = digitalRead(CLK_PIN);
+  bool dt = digitalRead(DT_PIN);
+
+  // only handle change
+  if (clk == previousClk && dt == previousDt) {
+    return;
+  }
+
+  // TODO: Do we need to debounce encoder?
+
+  // clockwise pattern:
+  // clk: 1001 1001
+  // dt:  1100 1100
+  // counter-clockwise pattern:
+  // clk: 1100 1100
+  // dt:  1001 1001
+  if (clk == dt) {
+    if (clk == previousClk) {
+      Serial.println("Clockwise");
+    } else {
+      Serial.println("Counter-clockwise");
+    }
+  }
+
+  // save state
+  previousClk = clk;
+  previousDt = dt;
+}