Fix LED buffer size calculation

wled00/FX_fcn.cpp

@@ -1178,17 +1178,42 @@ void WS2812FX::finalizeInit() {
   digitalCount = 0;
   #endif
 
+  DEBUG_PRINTF_P(PSTR("Heap before buses: %d\n"), getFreeHeapSize());
   // create buses/outputs
   unsigned mem = 0;
+  unsigned maxI2S = 0;
   for (const auto &bus : busConfigs) {
-    mem += bus.memUsage(Bus::isDigital(bus.type) && !Bus::is2Pin(bus.type) ? digitalCount++ : 0); // includes global buffer
-    if (mem <= MAX_LED_MEMORY) {
-      if (BusManager::add(bus) == -1) break;
+    unsigned memB = bus.memUsage(Bus::isDigital(bus.type) && !Bus::is2Pin(bus.type) ? digitalCount++ : 0); // does not include DMA/RMT buffer
+    mem += memB;
+    // estimate maximum I2S memory usage (only relevant for digital non-2pin busses)
+    #if !defined(CONFIG_IDF_TARGET_ESP32C3) && !defined(ESP8266)
+      #if defined(CONFIG_IDF_TARGET_ESP32) || defined(CONFIG_IDF_TARGET_ESP32S3)
+    const bool usesI2S = ((useParallelI2S && digitalCount <= 8) || (!useParallelI2S && digitalCount == 1));
+      #elif defined(CONFIG_IDF_TARGET_ESP32S2)
+    const bool usesI2S = (useParallelI2S && digitalCount <= 8);
+      #else
+    const bool usesI2S = false;
+      #endif
+    if (Bus::isDigital(bus.type) && !Bus::is2Pin(bus.type) && usesI2S) {
+      #ifdef NPB_CONF_4STEP_CADENCE
+      constexpr unsigned stepFactor = 4; // 4 step cadence (4 bits per pixel bit)
+      #else
+      constexpr unsigned stepFactor = 3; // 3 step cadence (3 bits per pixel bit)
+      #endif
+      unsigned i2sCommonSize = stepFactor * bus.count * (3*Bus::hasRGB(bus.type)+Bus::hasWhite(bus.type)+Bus::hasCCT(bus.type)) * (Bus::is16bit(bus.type)+1);
+      if (i2sCommonSize > maxI2S) maxI2S = i2sCommonSize;
+    }
+    #endif
+    if (mem + maxI2S <= MAX_LED_MEMORY) {
+      BusManager::add(bus);
+      DEBUG_PRINTF_P(PSTR("Bus memory: %uB\n"), memB);
     } else {
       errorFlag = ERR_NORAM_PX; // alert UI
       DEBUG_PRINTF_P(PSTR("Out of LED memory! Bus %d (%d) #%u not created."), (int)bus.type, (int)bus.count, digitalCount);
+      break;
     }
   }
+  DEBUG_PRINTF_P(PSTR("LED buffer size: %uB/%uB\n"), mem + maxI2S, BusManager::memUsage());
   busConfigs.clear();
   busConfigs.shrink_to_fit();
 

wled00/bus_manager.cpp

@@ -324,7 +324,7 @@ size_t BusDigital::getPins(uint8_t* pinArray) const {
 }
 
 size_t BusDigital::getBusSize() const {
-  return sizeof(BusDigital) + (isOk() ? PolyBus::getDataSize(_busPtr, _iType) : 0);
+  return sizeof(BusDigital) + (isOk() ? PolyBus::getDataSize(_busPtr, _iType) : 0); // does not include common I2S DMA buffer
 }
 
 void BusDigital::setColorOrder(uint8_t colorOrder) {
@@ -760,7 +760,8 @@ size_t BusConfig::memUsage(unsigned nr) const {
   if (Bus::isVirtual(type)) {
     return sizeof(BusNetwork) + (count * Bus::getNumberOfChannels(type));
   } else if (Bus::isDigital(type)) {
-    return sizeof(BusDigital) + PolyBus::memUsage(count + skipAmount, PolyBus::getI(type, pins, nr)) /*+ doubleBuffer * (count + skipAmount) * Bus::getNumberOfChannels(type)*/;
+    // if any of digital buses uses I2S, there is additional common I2S DMA buffer not accounted for here
+    return sizeof(BusDigital) + PolyBus::memUsage(count + skipAmount, PolyBus::getI(type, pins, nr));
   } else if (Bus::isOnOff(type)) {
     return sizeof(BusOnOff);
   } else {
@@ -776,23 +777,23 @@ size_t BusManager::memUsage() {
   unsigned maxI2S = 0;
   #if !defined(CONFIG_IDF_TARGET_ESP32C3) && !defined(ESP8266)
   unsigned digitalCount = 0;
-    #if defined(CONFIG_IDF_TARGET_ESP32S2) || defined(CONFIG_IDF_TARGET_ESP32S3)
-      #define MAX_RMT 4
-    #else
-      #define MAX_RMT 8
-    #endif
   #endif
   for (const auto &bus : busses) {
-    unsigned busSize = bus->getBusSize();
+    size += bus->getBusSize();
     #if !defined(CONFIG_IDF_TARGET_ESP32C3) && !defined(ESP8266)
-    if (bus->isDigital() && !bus->is2Pin()) digitalCount++;
-    if (PolyBus::isParallelI2S1Output() && digitalCount > MAX_RMT) {
-      unsigned i2sCommonSize = 3 * bus->getLength() * bus->getNumberOfChannels() * (bus->is16bit()+1);
-      if (i2sCommonSize > maxI2S) maxI2S = i2sCommonSize;
-      busSize -= i2sCommonSize;
+    if (bus->isDigital() && !bus->is2Pin()) {
+      digitalCount++;
+      if ((PolyBus::isParallelI2S1Output() && digitalCount <= 8) || (!PolyBus::isParallelI2S1Output() && digitalCount == 1)) {
+        #ifdef NPB_CONF_4STEP_CADENCE
+        constexpr unsigned stepFactor = 4; // 4 step cadence (4 bits per pixel bit)
+        #else
+        constexpr unsigned stepFactor = 3; // 3 step cadence (3 bits per pixel bit)
+        #endif
+        unsigned i2sCommonSize = stepFactor * bus->getLength() * bus->getNumberOfChannels() * (bus->is16bit()+1);
+        if (i2sCommonSize > maxI2S) maxI2S = i2sCommonSize;
+      }
     }
     #endif
-    size += busSize;
   }
   return size + maxI2S;
 }