Fix for ESP32-S3-WROOM-1: safe GPIO pins, serial flush, delays

- Switch pins: 2-7, 15-18 (avoids USB 19/20, PSRAM 26-32, JTAG 34-37)
- LED pins: 38-42, 45-48, 21 (high GPIOs, no special functions)
- Add Serial.flush() after init messages
- Increase startup delays for reliable serial output
- Board: esp32-s3-devkitc-1-n16r8

platformio.ini

@@ -3,17 +3,18 @@
 
 [env:esp32s3]
 platform = espressif32
-board = esp32-s3-devkitc-1
+board = esp32-s3-devkitc-1-n16r8
 framework = arduino
 
 lib_deps =
     adafruit/Adafruit TinyUSB Library@^2.0.0
-    adafruit/Adafruit NeoPixel
 
 build_flags =
+    -DARDUINO_USB_MODE=1
     -DARDUINO_USB_CDC_ON_BOOT=1
 
 monitor_speed = 115200
+monitor_port = /dev/ttyACM0
 
 board_build.partitions = default_8MB.csv
 board_build.arduino.memory_type = qio_opi

src/led_stub.cpp

@@ -2,7 +2,7 @@
 #include <Arduino.h>
 
 static const uint8_t LED_PINS[10] = {
-    11, 12, 13, 14, 15, 16, 17, 18, 19, 20
+    38, 39, 40, 41, 42, 45, 46, 47, 48, 21
 };
 
 DefaultLedStub::DefaultLedStub() : initialized(false) {
@@ -22,21 +22,23 @@ void DefaultLedStub::begin() {
     }
     initialized = true;
 
-    Serial.println("[LED] Startup colour cycle...");
+    Serial.println("[LED] Startup animation...");
 
     for (int i = 0; i < NUM_LEDS; i++) {
         digitalWrite(LED_PINS[i], HIGH);
-        Serial.printf("[LED] LED %d ON (GPIO %d)\n", i, LED_PINS[i]);
+        Serial.printf("[LED] LED %d ON  (GPIO %d)\n", i, LED_PINS[i]);
+        delay(150);
+    }
+
+    delay(300);
+
+    for (int i = NUM_LEDS - 1; i >= 0; i--) {
+        digitalWrite(LED_PINS[i], LOW);
+        Serial.printf("[LED] LED %d OFF (GPIO %d)\n", i, LED_PINS[i]);
         delay(100);
     }
 
-    for (int i = 0; i < NUM_LEDS; i++) {
+    Serial.println("[LED] Startup complete");
-        digitalWrite(LED_PINS[i], LOW);
-        delay(50);
-    }
-
-    clear_all();
-    Serial.println("[LED] Startup cycle complete");
 }
 
 void DefaultLedStub::set_led_state(uint8_t note, uint8_t channel, uint8_t velocity) {
@@ -57,7 +59,7 @@ void DefaultLedStub::set_led_state(uint8_t note, uint8_t channel, uint8_t veloci
                       note, led_index, channel, velocity,
                       velocity > 0 ? "ON" : "OFF");
     } else {
-        Serial.printf("[LED] Index out of range: %d (Note: %d)\n", led_index, note);
+        Serial.printf("[LED] Out of range: %d (Note: %d)\n", led_index, note);
     }
 }
 
@@ -69,5 +71,5 @@ void DefaultLedStub::clear_all() {
             digitalWrite(LED_PINS[i], LOW);
         }
     }
-    Serial.println("[LED] All LEDs cleared");
+    Serial.println("[LED] All cleared");
 }

src/main.cpp

@@ -26,17 +26,24 @@ void midi_task(void* parameter) {
 
 void setup() {
     Serial.begin(115200);
-    delay(1000);
+    delay(2000);
     
     Serial.println("=================================");
     Serial.println("  Loopy MIDI Controller v0.1");
     Serial.println("  Phase 1: USB MIDI");
+    Serial.println("  Board: ESP32-S3-WROOM-1");
     Serial.println("=================================");
     
+    Serial.println("[INIT] Starting LED startup animation...");
     led_driver.begin();
+    
+    Serial.println("[INIT] Initializing switches...");
     switch_driver.begin();
     
+    Serial.println("[INIT] Initializing USB MIDI...");
     midi_transport.begin();
+    
+    Serial.println("[INIT] Registering MIDI callbacks...");
     controller.begin();
     
     xTaskCreatePinnedToCore(
@@ -51,8 +58,9 @@ void setup() {
     
     Serial.println("=================================");
     Serial.println("  All systems ready");
-    Serial.println("  Waiting for USB connection...");
+    Serial.println("  Waiting for USB MIDI host...");
     Serial.println("=================================");
+    Serial.flush();
 }
 
 void loop() {

src/switch_stub.cpp

@@ -2,7 +2,7 @@
 #include <Arduino.h>
 
 static const uint8_t SWITCH_PINS[10] = {
-    1, 2, 3, 4, 5, 6, 7, 8, 9, 10
+    2, 3, 4, 5, 6, 7, 15, 16, 17, 18
 };
 
 DefaultSwitchStub::DefaultSwitchStub() : initialized(false) {
@@ -21,7 +21,7 @@ void DefaultSwitchStub::begin() {
         pinMode(switch_states[i].gpio_pin, INPUT_PULLUP);
     }
     initialized = true;
-    Serial.printf("[SW] Initialized %d switches on GPIOs: ", NUM_SWITCHES);
+    Serial.printf("[SW] %d switches on GPIOs: ", NUM_SWITCHES);
     for (int i = 0; i < NUM_SWITCHES; i++) {
         Serial.printf("%d ", switch_states[i].gpio_pin);
     }
@@ -57,12 +57,12 @@ void DefaultSwitchStub::configure_switch(uint8_t switch_id, uint8_t gpio_pin) {
     if (initialized) {
         pinMode(gpio_pin, INPUT_PULLUP);
     }
-    Serial.printf("[SW] Switch %d configured to GPIO %d\n", switch_id, gpio_pin);
+    Serial.printf("[SW] Switch %d -> GPIO %d\n", switch_id, gpio_pin);
 }
 
 void DefaultSwitchStub::set_debounce_time(uint32_t time_ms) {
     for (int i = 0; i < NUM_SWITCHES; i++) {
         switch_states[i].debounce_time = time_ms;
     }
-    Serial.printf("[SW] Debounce time set to %lu ms\n", time_ms);
+    Serial.printf("[SW] Debounce: %lu ms\n", time_ms);
 }