ESP32 rewrite PWM LEDC to use pin mux

DCCTimer.h

@@ -66,7 +66,9 @@ class DCCTimer {
   static void ackRailcomTimer();
   static void DCCEXanalogWriteFrequency(uint8_t pin, uint32_t frequency);
   static void DCCEXanalogWrite(uint8_t pin, int value);
-
+  static void DCCEXledcDetachPin(uint8_t pin);
+  static void DCCEXanalogCopyChannel(uint8_t frompin, uint8_t topin);
+  static void DCCEXInrushControlOn(uint8_t pin);
 // Update low ram level.  Allow for extra bytes to be specified
 // by estimation or inspection, that may be used by other 
 // called subroutines.  Must be called with interrupts disabled.

DCCTimerESP.cpp

@@ -78,6 +78,7 @@ int DCCTimer::freeMemory() {
 ////////////////////////////////////////////////////////////////////////
 
 #ifdef ARDUINO_ARCH_ESP32
+#include "DIAG.h"
 #include <driver/adc.h>
 #include <soc/sens_reg.h>
 #include <soc/sens_struct.h>
@@ -154,8 +155,10 @@ void DCCTimer::reset() {
 void DCCTimer::DCCEXanalogWriteFrequency(uint8_t pin, uint32_t f) {
   if (f >= 16)
     DCCTimer::DCCEXanalogWriteFrequencyInternal(pin, f);
-  else if (f == 7)
+/*
+  else if (f == 7) // not used on ESP32
     DCCTimer::DCCEXanalogWriteFrequencyInternal(pin, 62500);
+*/
   else if (f >= 4)
     DCCTimer::DCCEXanalogWriteFrequencyInternal(pin, 32000);
   else if (f >= 3)
@@ -188,22 +191,65 @@ void DCCTimer::DCCEXanalogWriteFrequencyInternal(uint8_t pin, uint32_t frequency
   }
 }
 
+void DCCTimer::DCCEXledcDetachPin(uint8_t pin) {
+  DIAG(F("Clear pin %d channel"), pin);
+  pin_to_channel[pin] = 0;
+  pinMatrixOutDetach(pin, false, false);
+}
+
+
+void DCCTimer::DCCEXanalogCopyChannel(uint8_t frompin, uint8_t topin) {
+  DIAG(F("Pin %d copied to %d channel %d"), frompin, topin, pin_to_channel[frompin]);
+  pin_to_channel[topin] = pin_to_channel[frompin];
+  ledcAttachPin(topin, pin_to_channel[topin]);
+}
 void DCCTimer::DCCEXanalogWrite(uint8_t pin, int value) {
+  // This allocates channels 15, 13, 11, ....
+  // so each channel gets its own timer.
   if (pin < SOC_GPIO_PIN_COUNT) {
     if (pin_to_channel[pin] == 0) {
+      int search_channel;
+      int n;
       if (!cnt_channel) {
           log_e("No more PWM channels available! All %u already used", LEDC_CHANNELS);
           return;
       }
-      pin_to_channel[pin] = --cnt_channel;
-      ledcSetup(cnt_channel, 1000, 8);
-      ledcAttachPin(pin, cnt_channel);
+      // search for free channels top down
+      for (search_channel=LEDC_CHANNELS-1; search_channel >=cnt_channel; search_channel -= 2) {
+	bool chanused = false;
+	for (n=0; n < SOC_GPIO_PIN_COUNT; n++) {
+	  if (pin_to_channel[n] == search_channel) { // current search_channel used
+	    chanused = true;
+	    break;
+	  }
+	}
+	if (chanused)
+	  continue;
+	if (n == SOC_GPIO_PIN_COUNT) // current search_channel unused
+	  break;
+      }
+      if (search_channel >= cnt_channel) {
+	pin_to_channel[pin] = search_channel;
+	DIAG(F("Pin %d assigned to search channel %d"), pin, search_channel);
+      } else {
+	pin_to_channel[pin] = --cnt_channel; // This sets 15, 13, ...
+	DIAG(F("Pin %d assigned to new channel %d"), pin, cnt_channel);
+	--cnt_channel;                       // Now we are at 14, 12, ...
+      }
+      ledcSetup(pin_to_channel[pin], 1000, 8);
+      ledcAttachPin(pin, pin_to_channel[pin]);
     } else {
+      //DIAG(F("Pin %d assigned to old channel %d"), pin, pin_to_channel[pin]);
       ledcAttachPin(pin, pin_to_channel[pin]);
     }
     ledcWrite(pin_to_channel[pin], value);
   }
 }
+void DCCTimer::DCCEXInrushControlOn(uint8_t pin) {
+  ledcSetup(0, 62500, 8);
+  ledcAttachPin(pin, 0);
+  ledcWrite(0, 207);
+}
 
 int ADCee::init(uint8_t pin) {
   pinMode(pin, ANALOG);

MotorDriver.cpp

@@ -411,10 +411,10 @@ void MotorDriver::throttleInrush(bool on) {
     duty = 255-duty;
 #if defined(ARDUINO_ARCH_ESP32)
   if(on) {
-    DCCTimer::DCCEXanalogWrite(brakePin,duty);
-    DCCTimer::DCCEXanalogWriteFrequency(brakePin, 7); // 7 means max
+    DCCTimer::DCCEXInrushControlOn(brakePin);
   } else {
-    ledcDetachPin(brakePin);
+    ledcDetachPin(brakePin); // not DCCTimer::DCCEXledcDetachPin() as we have not
+                             // registered the pin in the pin to channel array
   }
 #elif defined(ARDUINO_ARCH_STM32)
   if(on) {

MotorDriver.h

@@ -193,13 +193,14 @@ class MotorDriver {
       }
     };
     inline pinpair getSignalPin() { return pinpair(signalPin,signalPin2); };
+    inline byte getBrakePin() { return brakePin; };
     void setDCSignal(byte speedByte, uint8_t frequency=0);
     void throttleInrush(bool on);
     inline void detachDCSignal() {
 #if defined(__arm__)
       pinMode(brakePin, OUTPUT);
 #elif defined(ARDUINO_ARCH_ESP32)
-      ledcDetachPin(brakePin);
+      DCCTimer::DCCEXledcDetachPin(brakePin);
 #else
       setDCSignal(128);
 #endif

TrackManager.cpp

@@ -252,13 +252,32 @@ bool TrackManager::setTrackMode(byte trackToSet, TRACK_MODE mode, int16_t dcAddr
       track[trackToSet]->makeProgTrack(false); // only the prog track knows it's type
     }
     track[trackToSet]->setMode(mode);
-    trackDCAddr[trackToSet]=dcAddr;
 
     // When a track is switched, we must clear any side effects of its previous 
     // state, otherwise trains run away or just dont move.
 
     // This can be done BEFORE the PWM-Timer evaluation (methinks)
-    if (!(mode & TRACK_MODE_DC)) {
+    if (mode & TRACK_MODE_DC) {
+      if (trackDCAddr[trackToSet] != dcAddr) {
+	// if we change dcAddr, detach first old signal
+	track[trackToSet]->detachDCSignal();
+#ifdef ARDUINO_ARCH_ESP32
+	int trackfound = -1;
+	FOR_EACH_TRACK(t) {
+	  if ((track[t]->getMode() & TRACK_MODE_DC) && trackDCAddr[t] == dcAddr) {
+	    trackfound = t;
+	    break;
+	  }
+	}
+	if (trackfound > -1) {
+	  DCCTimer::DCCEXanalogCopyChannel(track[trackfound]->getBrakePin(),
+					   track[trackToSet]->getBrakePin());
+	}
+#endif
+      }
+      // set future DC Addr;
+      trackDCAddr[trackToSet]=dcAddr;
+    } else {
       // DCC tracks need to have set the PWM to zero or they will not work.
       track[trackToSet]->detachDCSignal();
       track[trackToSet]->setBrake(false);