added LDR evaluation + sensor edge detection

lib/treppe/treppe.cpp

@@ -1,6 +1,5 @@
 #include "treppe.h"
 
-
 /*
     dimm_stufe
     - dimmt stufe (0 - 15, PCA9685 outputs) mit linearen ticks
@@ -14,7 +13,7 @@ bool Treppe::dimm_stufe(uint8_t stufe)
     current_pwm += differenz_pwm_pro_tick;
   else
     current_pwm -= differenz_pwm_pro_tick;
-    pwmController.setChannelPWM(stufe, static_cast<uint16_t> (current_pwm));
+  pwmController.setChannelPWM(stufe, static_cast<uint16_t>(current_pwm));
 
   current_tick++;
   if (current_tick >= ticks_pro_stufe)
@@ -36,7 +35,8 @@ void Treppe::anim_tick()
 
     if (fsm_outputs.laufrichtung == LR_HOCH)
     {
-            if (stufe >= stufen-1) {
+      if (stufe >= stufen - 1)
+      {
         anim_beendet = true;
         return;
       }
@@ -44,7 +44,8 @@ void Treppe::anim_tick()
     }
     else
     {
-            if (stufe <= 0) {
+      if (stufe <= 0)
+      {
         anim_beendet = true;
         return;
       }
@@ -56,18 +57,22 @@ void Treppe::anim_tick()
 }
 
 // startbedingunen für animation
-void Treppe::start_animation() {
+void Treppe::start_animation()
+{
   anim_beendet = false;
 
-    if(fsm_outputs.laufrichtung == LR_HOCH)
+  if (fsm_outputs.laufrichtung == LR_HOCH)
     stufe = 0;
   else
-        stufe = stufen-1;
+    stufe = stufen - 1;
 
-    if(fsm_outputs.dimmrichtung == DR_AUFDIMMEN) {
+  if (fsm_outputs.dimmrichtung == DR_AUFDIMMEN)
+  {
     start_pwm = idle_brightness;
     ziel_pwm = active_brightness;
-    } else {
+  }
+  else
+  {
     start_pwm = active_brightness;
     ziel_pwm = idle_brightness;
   }
@@ -103,10 +108,95 @@ void Treppe::print_state_on_change()
   }
 }
 
+bool Treppe::read_sensor(int sensor)
+{
+
+  /*
+        reads sensors with edge detection
+        
+        returns true if motion was detected
+        returns false if no motion was detected
+        returns false if motion was detected, but state did not change back to not detected
+        */
+  uint8_t pegel = digitalRead(sensor);
+  static uint8_t pegel_alt[2] = {0, 0};
+
+  uint8_t index = 0;
+  if (sensor == SENSOR_OBEN)
+    index = 0;
+  else
+    index = 1;
+
+  if (pegel == 1 && pegel_alt[index] == 0)
+  {
+    pegel_alt[index] = pegel;
+    return true;
+  }
+  else
+  {
+    pegel_alt[index] = pegel;
+    return false;
+  }
+  //return static_cast<bool>(pegel);
+}
+
+float Treppe::read_ldr(){
+  /* 
+  Reads Illuminance in Lux
+
+  FUTURE USE : show current Illuminance on Webserver in order to calibrate
+
+  Voltage Divider 1 (R13, R14):
+  R13 = 220k, R14 = 82k
+  V(ADC) = V(in1) * R14/(R13+R14)
+  -> V(in1) = V(ADC) * (R13+R14)/R14
+  V(ADC) = analogRead(A0)/1023.00
+  -> V(in1) = analogRead(A0)/1023.00 * (R13+R14)/R14
+            = analogRead(A0) * (R13+R14)/(R14*1023.00)
+            = analogRead(A0) * (220k+82k)/(82k*1023.00)
+            = analogRead(A0) * 0.0036
+  
+  Voltage Divider 2 (LDR, R1 || (R13+R14))
+  R1 = 47k, R13+R14 = 302k -> R1||(R13+R14) = 40,67k
+  Vcc/V(in1) = R(LDR) / (R1||(R13+R14))
+  -> R(LDR) = Vcc/V(in1) * (R1||(R13+R14))
+  R(LDR) = 3.3V * 40.67k / V(in1)
+
+  Join formulas:
+
+  R(LDR) = 3.3V * 40.67k / (0.0036 * analogRead(A0))
+         = 37280.00/analogRead(A0)
+  ldr_ohm = R(LDR)
+
+  E(LDR) = 79.735 * R(LDR)^-0.498   (see Excel Regression)
+  ldr_value = E(LDR)
+  */
+  float ldr_ohm = 37280.00 / analogRead(A0);
+  float ldr_value = 79.735 * pow(ldr_ohm, -0.498);
+  return ldr_value;
+}
+
+
+bool Treppe::check_ldr()
+{
+  uint8_t active = 0;
+
+  #ifdef LDRDEBUG
+  Serial.printf("R(LDR) = %f kOhm  %f lux\n", ldr_value, lux);
+  return true;
+  #endif
+
+  // follow up: averaging over many samples?
+  if(read_ldr() < ldr_schwelle) active = 1;
+  if(read_ldr() > ldr_schwelle + LDR_HYS) active = 0;
+
+  return active; 
+}
+
 void Treppe::task()
 {
   //Serial.printf("LDR: %f\n", ((float)analogRead(A0))/1023.*3.68);
-    fsm_inputs.ldr_schwelle = true; // <=== LDR implementierung !!
+  fsm_inputs.ldr_schwelle = read_ldr(); // <=== LDR implementierung !!
 
   fsm_inputs.sensor_oben = read_sensor(SENSOR_OBEN);
   fsm_inputs.sensor_unten = read_sensor(SENSOR_UNTEN);
@@ -117,22 +207,23 @@ void Treppe::task()
   fsm_outputs = FSMTreppe_Obj.getExternalOutputs();
   print_state_on_change();
 
-    if(fsm_outputs.status > ST_RUHEZUSTAND) {
+  if (fsm_outputs.status > ST_RUHEZUSTAND)
-        if( anim_beendet == true &&
+  {
-            ( fsm_outputs.status == ST_AUFDIMMEN_HOCH || fsm_outputs.status == ST_ABDIMMEN_HOCH ||
+    if (anim_beendet == true &&
-            fsm_outputs.status == ST_AUFDIMMEN_RUNTER || fsm_outputs.status == ST_ABDIMMEN_RUNTER ))
+        (fsm_outputs.status == ST_AUFDIMMEN_HOCH || fsm_outputs.status == ST_ABDIMMEN_HOCH ||
+         fsm_outputs.status == ST_AUFDIMMEN_RUNTER || fsm_outputs.status == ST_ABDIMMEN_RUNTER))
     {
       start_animation();
     }
-        if( !anim_beendet )
+    if (!anim_beendet)
       anim_tick();
   }
 }
 
-void Treppe::berechne_dimmer() {
+void Treppe::berechne_dimmer()
+{
   ticks_pro_stufe = time_per_stair / INT_TIME; // [ms]
-    differenz_pwm_pro_tick = (float) (active_brightness - idle_brightness) 
+  differenz_pwm_pro_tick = (float)(active_brightness - idle_brightness) / (float)ticks_pro_stufe;
-                                        / (float) ticks_pro_stufe;
 }
 
 void Treppe::setup()

lib/treppe/treppe.h

@@ -3,6 +3,10 @@
 #include "FSMTreppe2/FSMTreppe2.h"
 #include "PCA9685.h"
 
+// #define LDRDEBUG  // comment in to override LDR measurement 
+
+#define LDR_HYS 5.0  // Hysteresis for switching off FSM [lux]
+
 #define SENSOR_OBEN 2
 #define SENSOR_UNTEN 12
 #define OE 14
@@ -16,6 +20,8 @@ private:
     uint16_t idle_brightness = 0;
     uint16_t active_brightness = 500;
 
+    uint16_t ldr_schwelle = 7;      // activation value for FSM [lx]
+
     uint16_t start_pwm = 0;
     uint16_t ziel_pwm  = 0;
     
@@ -56,10 +62,9 @@ private:
         DR_AUFDIMMEN=1
     };
 
-    bool read_sensor(int sensor) {
+    bool read_sensor(int sensor);
-        int pegel = digitalRead(sensor);
+    float read_ldr();
-        return static_cast<bool>(pegel);
+    bool check_ldr();
-    }
 public:
     Treppe(uint8_t _stufen) : stufen(_stufen){
         FSMTreppe_Obj.initialize();