From 8351effff15424b9f5ea766470cb545b336ec65b Mon Sep 17 00:00:00 2001
From: mikecarper <mikecarper@gmail.com>
Date: Mon, 31 Aug 2026 19:06:07 -0700
Subject: [PATCH] Recover Indicator display after warm reset

---
 examples/companion_radio/main.cpp             |  7 ++++-
 test/test_indicator_display_profile.py        | 11 +++++++
 .../SCIndicatorDisplay.h                      | 31 +++++++++++++++++--
 3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/examples/companion_radio/main.cpp b/examples/companion_radio/main.cpp
index 73075cd7..f23a4e0d 100644
--- a/examples/companion_radio/main.cpp
+++ b/examples/companion_radio/main.cpp
@@ -825,6 +825,7 @@ void halt() {
   static CompanionWiFiDisplayState companion_wifi_display_state =
       CompanionWiFiDisplayState::NotRendered;
   static uint32_t companion_wifi_display_frames = 0;
+  static bool companion_display_available = false;
 
 #if defined(COMPANION_EXCLUSIVE_WIFI_BLE)
   static CompanionTransportMode companion_transport_boot_mode =
@@ -1173,9 +1174,10 @@ void halt() {
     const bool idf_associated =
         esp_wifi_sta_get_ap_info(&access_point) == ESP_OK;
     snprintf(reply, reply_size,
-             "> state=%s, frames=%lu, requested=%u, services=%u, "
+             "> state=%s, frames=%lu, display=%u, requested=%u, services=%u, "
              "wl=%d, idf=%u, IP=%s",
              names[state], (unsigned long)companion_wifi_display_frames,
+             companion_display_available ? 1U : 0U,
              companion_wifi_requested ? 1U : 0U,
              companion_wifi_active ? 1U : 0U, (int)WiFi.status(),
              idf_associated ? 1U : 0U,
@@ -1733,6 +1735,9 @@ void setup() {
     disp->drawTextCentered(disp->width() / 2, 28, "Loading...");
     disp->endFrame();
   }
+#if defined(ESP32) && defined(WIFI_SSID)
+  companion_display_available = disp != NULL;
+#endif
 #endif
 
   int radioinit_attempts = 0;
diff --git a/test/test_indicator_display_profile.py b/test/test_indicator_display_profile.py
index d067d272..a553f4f2 100644
--- a/test/test_indicator_display_profile.py
+++ b/test/test_indicator_display_profile.py
@@ -9,6 +9,9 @@ import unittest
 ROOT = Path(__file__).resolve().parents[1]
 PROFILE = ROOT / "variants" / "sensecap_indicator-espnow" / "platformio.ini"
 DISPLAY = ROOT / "src" / "helpers" / "ui" / "LGFXDisplay.cpp"
+INDICATOR_DISPLAY = (
+    ROOT / "variants" / "sensecap_indicator-espnow" / "SCIndicatorDisplay.h"
+)
 FONT = ROOT / "variants" / "sensecap_indicator-espnow" / "sd" / "ui-font.vlw"
 
 
@@ -36,6 +39,14 @@ def numeric_flag(name: str) -> float:
 
 
 class IndicatorDisplayProfileTest(unittest.TestCase):
+    def test_panel_cs_release_cannot_discard_initialized_display(self):
+        display = INDICATOR_DISPLAY.read_text()
+        self.assertIn("releasePanelChipSelectWithRetry()", display)
+        self.assertIn("if (!initialized) return false;", display)
+        self.assertNotIn("if (!initialized || !released) return false;", display)
+        self.assertIn("panel_chip_select_released =", display)
+        self.assertIn("void startFrame(ColorVal bkg", display)
+
     def test_preserves_original_indicator_memory_profile(self):
         profile = base_profile()
         self.assertIn("board_build.arduino.memory_type = qio_opi", profile)
diff --git a/variants/sensecap_indicator-espnow/SCIndicatorDisplay.h b/variants/sensecap_indicator-espnow/SCIndicatorDisplay.h
index c5dd9353..07c784a6 100644
--- a/variants/sensecap_indicator-espnow/SCIndicatorDisplay.h
+++ b/variants/sensecap_indicator-espnow/SCIndicatorDisplay.h
@@ -129,6 +129,7 @@ class SCIndicatorDisplay : public LGFXDisplay {
   LGFX disp;
   uint8_t expander_address = 0;
   uint16_t expander_output = 0;
+  bool panel_chip_select_released = false;
 
   static constexpr gpio_num_t BACKLIGHT_PIN = GPIO_NUM_45;
   static constexpr uint8_t I2C_PORT = 0;
@@ -230,6 +231,20 @@ class SCIndicatorDisplay : public LGFXDisplay {
                                  expander_output);
   }
 
+  bool releasePanelChipSelectWithRetry() {
+    // LovyanGFX initializes the touch controller on this same I2C bus. On a
+    // warm ESP32-S3 reset its final transaction can briefly leave the
+    // expander unavailable even though the RGB panel and render buffer were
+    // initialized successfully. Re-open the bus and retry before LoRa starts
+    // using the panel's shared SCLK/MOSI pins.
+    for (uint8_t attempt = 0; attempt < 10; ++attempt) {
+      if (releasePanelChipSelect()) return true;
+      delay(5);
+      lgfx::i2c::init(I2C_PORT, PIN_BOARD_SDA, PIN_BOARD_SCL);
+    }
+    return false;
+  }
+
 public:
 #if defined(INDICATOR_TRANSPORT_RENDER_PROFILE)
   // Full builds always use the established 160x160 logical layout. State it
@@ -245,8 +260,13 @@ public:
   bool begin() {
     if (!prepareControllers()) return false;
     const bool initialized = LGFXDisplay::begin();
-    const bool released = releasePanelChipSelect();
-    if (!initialized || !released) return false;
+    if (!initialized) return false;
+
+    // A failed CS release must not discard an otherwise valid 115 KiB render
+    // buffer and leave the LCD showing its pre-reset scanout forever. Keep the
+    // UI alive and retry from startFrame(); the common case succeeds here
+    // before the external LoRa radio is initialized.
+    panel_chip_select_released = releasePanelChipSelectWithRetry();
     setBacklight(true);
     size_t fontSize;
     uint8_t* fontData = IndicatorFontClient::load(fontSize);
@@ -263,6 +283,13 @@ public:
     return true;
   }
 
+  void startFrame(ColorVal bkg = UIColor::window_bkg) override {
+    if (!panel_chip_select_released) {
+      panel_chip_select_released = releasePanelChipSelectWithRetry();
+    }
+    LGFXDisplay::startFrame(bkg);
+  }
+
 #ifdef INDICATOR_WIFI_FONT_RECOVERY
   void serviceFontRecovery() {
     size_t fontSize = 0;