Test-Stand/Overview.md

@@ -15,38 +15,88 @@ See here: https://git.ece.iastate.edu/danc/MicroCART/-/wikis/Test-Stand/Electron
 
 # The Firmware
 ``` cpp
-int analogPin = A7;
-int btnPin = 2;
+const int DATA_PIN = A7;
+const int BUTTON_PIN = 2;
 int buttonState = 0;
 
 int val = 0;
-double scalar = 0.3516; // 360/1024
+const double TEN_BIT_SCALAR = 0.3516; // 360/1024
 int homePosition;
 
+// Rate variables
+long lastTime = 0;
+long currTime = 0;
+long lastReading = 0;
+long currReading = 0;
+
+long deltaTime = 0;
+long deltaReading = 0;
+
+double rate;
+
+// Long Press Variables
+long buttonTimer = 0;
+const long LONG_PRESS_MILLIS = 250;
+boolean buttonActive = false;
+boolean longPressActive = false;
+boolean isInPositionMode = true;
 
 void setup() {
   // put your setup code here, to run once:
   Serial.begin(9600);
-  pinMode(btnPin, INPUT);
+  pinMode(BUTTON_PIN, INPUT);
   pinMode(LED_BUILTIN, OUTPUT);
-  homePosition = analogRead(analogPin);
+  homePosition = analogRead(DATA_PIN);
+  lastTime = millis();
+  lastReading = analogRead(DATA_PIN);
 }
 
 void loop() {
-  // put your main code here, to run repeatedly:
-     buttonState = digitalRead(btnPin);
-     if(buttonState == HIGH){
-      digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
-      homePosition = analogRead(analogPin); 
+  currTime = millis();
+  currReading = analogRead(DATA_PIN);
+  
+  if(digitalRead(BUTTON_PIN) == HIGH){
+    if(buttonActive == false){ // Button was not pressed last cycle
+      buttonActive = true;
+      buttonTimer = millis();
+    }
+    if(((millis() - buttonTimer) > LONG_PRESS_MILLIS) && (longPressActive == false)){ // Detected a long press, swap modes
+      longPressActive = true;
+      isInPositionMode = !isInPositionMode; 
+    }
+  } 
+  else {
+    if(buttonActive == true){ // Button was being pressed last cycle
+      if(longPressActive == true){ // Button was being long pressed last cycle, user has released the long press
+        longPressActive = false;
+      }
+      else { // Short press occured, grab current position regardless of mode
+        homePosition = analogRead(DATA_PIN);
+      }
+      buttonActive = false;
+    }
   }  
   
-    val = analogRead(analogPin);
-    double absoluteDegrees = scalar * (double) val;
-    double relativeDegrees = scalar * (double) homePosition;
+  // LED on if we're in position mode, off if we're in rate mode
+  digitalWrite(LED_BUILTIN, isInPositionMode);
+
+  if(isInPositionMode == true){
+    double absoluteDegrees = TEN_BIT_SCALAR * (double) currReading;
+    double relativeDegrees = TEN_BIT_SCALAR * (double) homePosition;
     double displayPosition = absoluteDegrees - relativeDegrees;
-    if(displayPosition < 0) {
-      displayPosition = displayPosition + 360;
-    }
+    displayPosition += (displayPosition < 0)?(360):(0);
     Serial.println(displayPosition);
   }
+  else{ // We're in rate mode
+    deltaTime = currTime - lastTime;
+    deltaReading = currReading - lastReading;
+    rate = 1000 * ((TEN_BIT_SCALAR * deltaReading) / (deltaTime));
+    Serial.println(rate);
+  }
+
+  // Reset vars for next cycle
+  lastTime = currTime;
+  lastReading = currReading;
+}
+
 ```
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