feat: Add capacitive touch controls for Tidbyt Gen 2 (#130)

* feat: Add capacitive touch controls for Tidbyt Gen 2

Implements touch gestures on GPIO33 (TOUCH_PAD_NUM8):
- TAP: Skip to next app
- DOUBLE TAP: Reserved for future use
- HOLD (2s): Toggle display on/off

Features:
- Adaptive baseline tracking to handle display EMI drift
- Late tap detection to prevent accidental skips during double-tap
- Fast warmup period (5s) for quicker calibration on boot
- Debug logging (can be disabled via TOUCH_DEBUG_ENABLED)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* fix: Guard touch code for Gen2 only, fix display state sync

- Add #ifdef CONFIG_BOARD_TIDBYT_GEN2 guards around all touch code
- Conditionally compile touch_control.c only for Gen2 in CMakeLists
- Non-Gen2 devices use original 5s delay instead of touch polling
- Fix display_power_on sync when server sends brightness command

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: wurtz

main/CMakeLists.txt

@@ -12,18 +12,25 @@ if(NOT DEFINED VAL_REMOTE_URL)
     set(VAL_REMOTE_URL "XplaceholderREMOTEURL___________________________________________________________________________________________________________")
 endif()
 
-idf_component_register(SRCS "main.c" 
-                            "display.cpp" 
-                            "flash.c" 
-                            "gfx.c" 
-                            "ota.c" 
-                            "remote.c" 
-                            "wifi.c"
-                            "ap.c"
-                            "nvs_settings.c"
-                            "dns_wrapper.c"
-                            "syslog.c"
-                            "sntp.c"
+# Conditionally include touch_control.c only for Tidbyt Gen2
+set(SRCS "main.c"
+         "display.cpp"
+         "flash.c"
+         "gfx.c"
+         "ota.c"
+         "remote.c"
+         "wifi.c"
+         "ap.c"
+         "nvs_settings.c"
+         "dns_wrapper.c"
+         "syslog.c"
+         "sntp.c")
+
+if(CONFIG_BOARD_TIDBYT_GEN2)
+    list(APPEND SRCS "touch_control.c")
+endif()
+
+idf_component_register(SRCS ${SRCS}
                        INCLUDE_DIRS ".")
 
 idf_build_set_property(LINK_OPTIONS "-Wl,--wrap=esp_getaddrinfo" APPEND)

main/main.c

@@ -22,6 +22,9 @@
 #include "sdkconfig.h"
 #include "sntp.h"
 #include "syslog.h"
+#ifdef CONFIG_BOARD_TIDBYT_GEN2
+#include "touch_control.h"
+#endif
 #include "version.h"
 #include "wifi.h"
 
@@ -54,6 +57,13 @@ static bool button_boot = false;
 static bool first_ws_image_received = false;
 static bool config_received = false;
 
+#ifdef CONFIG_BOARD_TIDBYT_GEN2
+// Touch control state
+static bool display_power_on = true;
+static uint8_t saved_brightness = 30;
+static void handle_touch_event(touch_event_t event);
+#endif
+
 static void config_saved_callback(void) {
   config_received = true;
   ESP_LOGI(TAG, "Configuration saved - signaling main task");
@@ -201,6 +211,11 @@ static void websocket_event_handler(void* handler_args, esp_event_base_t base,
                   brightness_value = DISPLAY_MAX_BRIGHTNESS;
                 display_set_brightness((uint8_t)brightness_value);
                 ESP_LOGI(TAG, "Updated brightness to %d", brightness_value);
+#ifdef CONFIG_BOARD_TIDBYT_GEN2
+                // Sync touch control state - server brightness command means display is on
+                display_power_on = true;
+                saved_brightness = (uint8_t)brightness_value;
+#endif
               }
 
               // Check for "ota_url"
@@ -496,6 +511,19 @@ void app_main(void) {
   }
   esp_register_shutdown_handler(&display_shutdown);
 
+#ifdef CONFIG_BOARD_TIDBYT_GEN2
+  // Initialize touch controls (GPIO33 on Tidbyt Gen2)
+  ESP_LOGI(TAG, "Initializing touch control...");
+  esp_err_t touch_ret = touch_control_init();
+  if (touch_ret == ESP_OK) {
+    ESP_LOGI(TAG, "Touch control ready on GPIO33");
+    touch_control_debug_all_pads();
+  } else {
+    ESP_LOGW(TAG, "Touch control init failed: %s (continuing without touch)",
+             esp_err_to_name(touch_ret));
+  }
+#endif
+
   // Start the AP web server now that display memory is allocated
   if (nvs_get_ap_mode()) {
     ESP_LOGI(TAG, "Starting AP Web Server...");
@@ -692,7 +720,20 @@ void app_main(void) {
       }
 
       wifi_health_check();
-      vTaskDelay(pdMS_TO_TICKS(5000));  // check every 5s
+
+#ifdef CONFIG_BOARD_TIDBYT_GEN2
+      // Poll touch frequently for 5 seconds (50ms intervals = 100 checks)
+      // This allows proper gesture detection while keeping health checks at 5s
+      for (int i = 0; i < 100; i++) {
+        touch_event_t touch_event = touch_control_check();
+        if (touch_event != TOUCH_EVENT_NONE) {
+          handle_touch_event(touch_event);
+        }
+        vTaskDelay(pdMS_TO_TICKS(50));  // 50ms = responsive touch
+      }
+#else
+      vTaskDelay(pdMS_TO_TICKS(5000));  // 5 second health check interval
+#endif
     }
   } else {
     // normal http
@@ -778,7 +819,62 @@ void app_main(void) {
           isAnimating = 1;
         }
       }
+
+#ifdef CONFIG_BOARD_TIDBYT_GEN2
+      // Check for touch events
+      touch_event_t touch_event = touch_control_check();
+      if (touch_event != TOUCH_EVENT_NONE) {
+        handle_touch_event(touch_event);
+      }
+#endif
+
       wifi_health_check();
     }
   }
 }
+
+#ifdef CONFIG_BOARD_TIDBYT_GEN2
+/**
+ * Handle touch events from the single touch pad
+ * TAP = skip to next app
+ * DOUBLE_TAP = (reserved for future use)
+ * HOLD = toggle display power on/off
+ */
+static void handle_touch_event(touch_event_t event) {
+  ESP_LOGI(TAG, "Touch event: %s", touch_event_to_string(event));
+
+  switch (event) {
+    case TOUCH_EVENT_TAP:
+      if (display_power_on) {
+        ESP_LOGI(TAG, "TAP - skip to next app");
+        isAnimating = -1;
+      } else {
+        ESP_LOGI(TAG, "TAP ignored - display is off (hold to turn on)");
+      }
+      break;
+
+    case TOUCH_EVENT_DOUBLE_TAP:
+      // Reserved for future use
+      ESP_LOGI(TAG, "DOUBLE TAP - no action assigned");
+      break;
+
+    case TOUCH_EVENT_HOLD:
+      display_power_on = !display_power_on;
+
+      if (display_power_on) {
+        ESP_LOGI(TAG, "HOLD - Display ON");
+        display_set_brightness(saved_brightness);
+        isAnimating = 1;
+      } else {
+        ESP_LOGI(TAG, "HOLD - Display OFF");
+        saved_brightness = 30;
+        display_set_brightness(0);
+        isAnimating = 0;
+      }
+      break;
+
+    default:
+      break;
+  }
+}
+#endif