tuned amp, added transistor for button

baby-mobile-v5.kicad_sch

@@ -9,7 +9,7 @@
 		(date "2026-03-11")
 		(rev "5.0")
 		(comment 1 "XIAO nRF52840 + IS25LP128F + TPS61220")
-		(comment 2 "Key-shaped panel with breakaway SOP adapters")
+		(comment 2 "Intended for Baby Trend Smart Steps Activity Center AC01E21B/WK03F23A/WK03E69A")
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+					(size 1.27 1.27)
+				)
+				(hide yes)
+			)
+		)
+		(pin "1"
+			(uuid "0a220a46-0a33-4667-91ae-503c386e41c9")
+		)
+		(pin "2"
+			(uuid "fb0d31a7-90ef-4de3-881a-7ae2f20c8699")
+		)
+		(instances
+			(project "baby-mobile-v5"
+				(path "/3033f063-d051-4b2e-89f5-f1cfe4577b32"
+					(reference "R8")
+					(unit 1)
+				)
+			)
+		)
+	)
+	(symbol
+		(lib_id "Transistor_BJT:2N3904")
+		(at 185.42 204.47 180)
+		(unit 1)
+		(exclude_from_sim no)
+		(in_bom yes)
+		(on_board yes)
+		(dnp no)
+		(fields_autoplaced yes)
+		(uuid "a084e525-c37b-4d70-9877-91e81d08aa4f")
+		(property "Reference" "Q1"
+			(at 180.34 203.1999 0)
+			(effects
+				(font
+					(size 1.27 1.27)
+				)
+				(justify left)
+			)
+		)
+		(property "Value" "2N3904"
+			(at 180.34 205.7399 0)
+			(effects
+				(font
+					(size 1.27 1.27)
+				)
+				(justify left)
+			)
+		)
+		(property "Footprint" "Package_TO_SOT_THT:TO-92_Inline"
+			(at 180.34 202.565 0)
+			(effects
+				(font
+					(size 1.27 1.27)
+					(italic yes)
+				)
+				(justify left)
+				(hide yes)
+			)
+		)
+		(property "Datasheet" "https://www.onsemi.com/pub/Collateral/2N3903-D.PDF"
+			(at 185.42 204.47 0)
+			(effects
+				(font
+					(size 1.27 1.27)
+				)
+				(justify left)
+				(hide yes)
+			)
+		)
+		(property "Description" "0.2A Ic, 40V Vce, Small Signal NPN Transistor, TO-92"
+			(at 185.42 204.47 0)
+			(effects
+				(font
+					(size 1.27 1.27)
+				)
+				(hide yes)
+			)
+		)
+		(pin "1"
+			(uuid "7f9fd381-05b7-4d2b-ac20-94427f8e62e1")
+		)
+		(pin "3"
+			(uuid "cff7bea6-19f9-40d7-a972-ac8cf6dfad14")
+		)
+		(pin "2"
+			(uuid "0af396b5-4483-4ff1-af5c-8a8183d14f57")
+		)
+		(instances
+			(project ""
+				(path "/3033f063-d051-4b2e-89f5-f1cfe4577b32"
+					(reference "Q1")
+					(unit 1)
+				)
+			)
+		)
+	)
 	(symbol
 		(lib_id "bm:C")
 		(at 342.9 87.61 0)
@@ -6036,6 +6639,76 @@
 			)
 		)
 	)
+	(symbol
+		(lib_id "Device:R")
+		(at 193.04 194.31 0)
+		(unit 1)
+		(exclude_from_sim no)
+		(in_bom yes)
+		(on_board yes)
+		(dnp no)
+		(fields_autoplaced yes)
+		(uuid "b54e60f2-827e-4365-b528-af504d173765")
+		(property "Reference" "R6"
+			(at 195.58 193.0399 0)
+			(effects
+				(font
+					(size 1.27 1.27)
+				)
+				(justify left)
+			)
+		)
+		(property "Value" "470K"
+			(at 195.58 195.5799 0)
+			(effects
+				(font
+					(size 1.27 1.27)
+				)
+				(justify left)
+			)
+		)
+		(property "Footprint" "Resistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P1.90mm_Vertical"
+			(at 191.262 194.31 90)
+			(effects
+				(font
+					(size 1.27 1.27)
+				)
+				(hide yes)
+			)
+		)
+		(property "Datasheet" "~"
+			(at 193.04 194.31 0)
+			(effects
+				(font
+					(size 1.27 1.27)
+				)
+				(hide yes)
+			)
+		)
+		(property "Description" "Resistor"
+			(at 193.04 194.31 0)
+			(effects
+				(font
+					(size 1.27 1.27)
+				)
+				(hide yes)
+			)
+		)
+		(pin "1"
+			(uuid "6f9f0b6b-5a88-4bb9-9f21-6253efd1bc15")
+		)
+		(pin "2"
+			(uuid "5762cfc4-fd1c-46bf-b4d0-0226bbde2e21")
+		)
+		(instances
+			(project "baby-mobile-v5"
+				(path "/3033f063-d051-4b2e-89f5-f1cfe4577b32"
+					(reference "R6")
+					(unit 1)
+				)
+			)
+		)
+	)
 	(symbol
 		(lib_id "bm:C")
 		(at 344.17 76.18 90)

baby_mobile_v2/baby_mobile_v2.ino

@@ -52,7 +52,15 @@
 // ============================================================
 // When defined, a wake from deep sleep (button press) plays a random track
 // immediately instead of waiting for user input.
-//#define WAKE_PLAY_RANDOM
+#define WAKE_PLAY_RANDOM
+
+// ============================================================
+// Button playback mode:
+//   Undefined  — short press toggles play/stop (press again to stop).
+//   Defined    — every press always starts a track; never stops mid-play.
+//                If WAKE_PLAY_RANDOM is also defined, picks a random track;
+//                otherwise advances to the next track (wrapping around).
+#define BTN_ALWAYS_START
 
 // ============================================================
 // POC MODE: stream audio from internal LittleFS instead of SPI flash.
@@ -89,10 +97,10 @@ using namespace Adafruit_LittleFS_Namespace;
 
 // Buttons (directly to GPIO, active LOW with internal pull-up)
 #define PIN_BTN1         1
+/*
 #define PIN_BTN2         1
 #define PIN_BTN3         1
 #define PIN_BTN4         1
-/*
 #define PIN_BTN5         4
 #define PIN_BTN6         5
 #define PIN_BTN7         3
@@ -104,10 +112,10 @@ using namespace Adafruit_LittleFS_Namespace;
 // LED_G is 12/13
 
 const uint8_t BTN_PINS[] = {
-    PIN_BTN1, PIN_BTN2, PIN_BTN3, PIN_BTN4,
+    PIN_BTN1 /*, PIN_BTN2, PIN_BTN3, PIN_BTN4,*/
     /*PIN_BTN5, PIN_BTN6, PIN_BTN7, PIN_BTN8*/
 };
-#define NUM_BUTTONS 4
+#define NUM_BUTTONS 1
 
 // ============================================================
 // FLASH CONSTANTS
@@ -255,6 +263,7 @@ volatile bool g_usbConnected = false;
 // Wake-from-sleep detection. Read before SoftDevice starts (setupBLE), stored here.
 static bool     g_wakeFromSleep  = false;
 static uint8_t  g_wakeTrack      = 0;
+static uint32_t g_debugResetreas = 0;  // printed 10 s after boot for post-sleep diagnosis
 
 #ifdef POC_INTERNAL_FLASH
 static void pocFilename(uint8_t n, char *buf) {  // buf must be >=16 bytes
@@ -1456,13 +1465,17 @@ void setup() {
     // Read RESETREAS and collect a random byte BEFORE starting the SoftDevice.
     // Once Bluefruit.begin() enables S140, the SoftDevice owns NRF_RNG and
     // NRF_POWER — direct register access after that point causes a hard fault.
-    g_wakeFromSleep = (NRF_POWER->RESETREAS & POWER_RESETREAS_OFF_Msk) != 0;
+    uint32_t resetreas = NRF_POWER->RESETREAS;
     NRF_POWER->RESETREAS = 0xFFFFFFFFUL;  // write-1-to-clear
-    if (g_wakeFromSleep) Serial.println("Woke from deep sleep.");
+    g_wakeFromSleep = (resetreas & POWER_RESETREAS_OFF_Msk) != 0;
+    g_debugResetreas = resetreas;  // printed 10 s after boot once serial reconnects
+    // Seed Arduino random() from hardware RNG now, before Bluefruit.begin().
+    // After the SoftDevice starts it owns NRF_RNG — hwRandom() must not be
+    // called again after that point.  Use random() everywhere in loop().
+    randomSeed(hwRandom());
 #ifdef WAKE_PLAY_RANDOM
     if (g_wakeFromSleep && g_numTracks > 0) {
-        // hwRandom() is safe here — SoftDevice not yet started.
+        g_wakeTrack = (uint8_t)random(g_numTracks);
-        g_wakeTrack = hwRandom() % g_numTracks;
     }
 #endif
 
@@ -1752,6 +1765,16 @@ static void serUploadTick() {
 void loop() {
     if (g_playing || g_bleUploading) g_lastActivity = millis();
 
+    // Print RESETREAS once, 10 s after boot, so serial has time to reconnect
+    // after a wake-from-sleep reset.
+    static bool resetreasLogged = false;
+    if (!resetreasLogged && millis() > 10000) {
+        resetreasLogged = true;
+        Serial.print("RESETREAS: 0x"); Serial.println(g_debugResetreas, HEX);
+        Serial.print("g_wakeFromSleep: "); Serial.println(g_wakeFromSleep);
+        Serial.print("g_numTracks: "); Serial.println(g_numTracks);
+    }
+
     // ---- Serial upload ----
     serUploadTick();
 
@@ -1799,14 +1822,27 @@ void loop() {
                         if (g_trackDoneMs != 0 && millis() >= g_trackDoneMs) {
                             g_trackDoneMs = 0; audioStop();
                         }
+                    } else {
+                        delay(1);  // yield to RTOS idle task so the watchdog gets fed
                     }
                 }
                 if (longPress) {
                     startBLEAdvertising();
                     waitButtonRelease(1);
                 } else {
+#ifdef BTN_ALWAYS_START
+                    if (g_numTracks > 0) {
+                        if (g_playing) audioStop();
+#ifdef WAKE_PLAY_RANDOM
+                        audioStart((uint8_t)random(g_numTracks));
+#else
+                        audioStart((g_currentTrack + 1) % g_numTracks);
+#endif
+                    }
+#else
                     if (g_playing) { audioStop(); }
                     else if (g_numTracks > 0) { audioStart(g_currentTrack); }
+#endif
                 }
                 break;
             }
@@ -1814,11 +1850,22 @@ void loop() {
             case 3:
             case 4:
             case 5:
+#ifdef BTN_ALWAYS_START
+                if (g_numTracks > 0) {
+                    if (g_playing) audioStop();
+#ifdef WAKE_PLAY_RANDOM
+                    audioStart((uint8_t)random(g_numTracks));
+#else
+                    audioStart((g_currentTrack + 1) % g_numTracks);
+#endif
+                }
+#else
                 if (g_playing) {
                     audioStop();
                 } else if (g_numTracks > 0) {
                     audioStart(g_currentTrack);
                 }
+#endif
                 break;
 /*
             case 4:  // Next track