Merge pull request #80 from xJARiD/develop

Fix SH1106 boot crash and update release notes for display fix

release-notes.yml

@@ -368,6 +368,21 @@ releases:
     breaking_changes:
       - "Saved settings move to the new `prefs.json` format on first boot; downgrading to earlier firmware afterwards reverts the device to the old (pre-migration) settings file."
 
+  - track: observer-eastmesh
+    version: "2026.8.1"
+    tag: "observer-eastmesh-v2026.8.1"
+    date: "2026-08-09"
+    previous_version: "2026.8.0"
+    summary: "Hardens T-Beam S3 Supreme display bring-up so a failed boot-time OLED probe can no longer crash-loop the node."
+    changes:
+      - type: fixed
+        area: board
+        text: "Restored the proven T-Beam S3 Supreme SH1106 bring-up order (initialise the display before probing the bus, which can NAK cold probes on this board) so the OLED reliably comes up at boot."
+      - type: fixed
+        area: board
+        text: "Made a failed or absent SH1106 display boot the node headless instead of crash-looping: display operations are now safe no-ops when the boot-time initialisation did not succeed."
+    breaking_changes: []
+
   - track: observer-eastmesh-bridge-espnow
     version: "2026.5.1"
     tag: "observer-eastmesh-bridge-espnow-v2026.5.1"
@@ -597,3 +612,18 @@ releases:
         text: "Fixed the web panel refusing connections (browser `PR_CONNECT_RESET_ERROR`) after long uptimes by evicting stale keep-alive connections instead of letting vanished clients permanently occupy the connection pool."
     breaking_changes:
       - "Saved settings move to the new `prefs.json` format on first boot; downgrading to earlier firmware afterwards reverts the device to the old (pre-migration) settings file."
+
+  - track: observer-eastmesh-bridge-espnow
+    version: "2026.8.1"
+    tag: "observer-eastmesh-bridge-espnow-v2026.8.1"
+    date: "2026-08-09"
+    previous_version: "2026.8.0"
+    summary: "Hardens T-Beam S3 Supreme display bring-up so a failed boot-time OLED probe can no longer crash-loop the node."
+    changes:
+      - type: fixed
+        area: board
+        text: "Restored the proven T-Beam S3 Supreme SH1106 bring-up order (initialise the display before probing the bus, which can NAK cold probes on this board) so the OLED reliably comes up at boot."
+      - type: fixed
+        area: board
+        text: "Made a failed or absent SH1106 display boot the node headless instead of crash-looping: display operations are now safe no-ops when the boot-time initialisation did not succeed."
+    breaking_changes: []

src/helpers/ui/SH1106Display.cpp

@@ -23,29 +23,39 @@ ColorVal UIColor::corp_blue = SH110X_WHITE;
 bool SH1106Display::begin()
 {
 #if defined(ESP32) && defined(TBEAM_SUPREME_SX1262) && defined(PIN_BOARD_SDA) && defined(PIN_BOARD_SCL)
+  // The S3 Supreme OLED bus NAKs cold address probes on some boards, so run the
+  // Adafruit init (with its reset sequence) first, then settle the bus before
+  // verifying the display responds.
+  _began = display.begin(DISPLAY_ADDRESS, true);
   Wire.begin(PIN_BOARD_SDA, PIN_BOARD_SCL);
   Wire.setClock(100000);
-#endif
+  _began = _began && i2c_probe(Wire, DISPLAY_ADDRESS);
+#else
   // Wire must already be initialised by board.begin() before this is called.
   // Boards with non-standard SH1106 addresses should define DISPLAY_ADDRESS
   // in their variant/platformio configuration.
-  return i2c_probe(Wire, DISPLAY_ADDRESS) && display.begin(DISPLAY_ADDRESS, true);
+  _began = i2c_probe(Wire, DISPLAY_ADDRESS) && display.begin(DISPLAY_ADDRESS, true);
+#endif
+  return _began;
 }
 
 void SH1106Display::turnOn()
 {
+  if (!_began) return;  // display.begin() never ran; oled_command would crash on a null bus device
   display.oled_command(SH110X_DISPLAYON);
   _isOn = true;
 }
 
 void SH1106Display::turnOff()
 {
+  if (!_began) return;
   display.oled_command(SH110X_DISPLAYOFF);
   _isOn = false;
 }
 
 void SH1106Display::clear()
 {
+  if (!_began) return;
   display.clearDisplay();
   display.display();
 }

src/helpers/ui/SH1106Display.h

@@ -18,12 +18,13 @@ class SH1106Display : public DisplayDriver
 {
   Adafruit_SH1106G display;
   bool _isOn;
+  bool _began;
   uint8_t _color;
 
   bool i2c_probe(TwoWire &wire, uint8_t addr);
 
 public:
-  SH1106Display() : DisplayDriver(128, 64), display(128, 64, &Wire, PIN_OLED_RESET) { _isOn = false; }
+  SH1106Display() : DisplayDriver(128, 64), display(128, 64, &Wire, PIN_OLED_RESET) { _isOn = false; _began = false; }
   bool begin();
 
   bool isOn() override { return _isOn; }