leds: PWM brightness control, persisted, with TX/RX pin-share arbitration

docs/CLI_commands.md

@@ -358,8 +358,9 @@ The observer role (ESP32, `boards/common/observer.conf`) has its own CLI and non
 | `get owner.info` | Owner/contact info (pipes `\|` display as newlines) |
 | `get int.thresh` | Interference threshold |
 | `get leds` | *(ZephCore only)* LED master switch: `on` or `off` |
-| `get leds.radio` | *(ZephCore only)* Activity-LED mode: `tx`, `rx`, `all` or `off`. Appends `(no radio LED on this board)` where the board has no `lora-tx-led` alias |
+| `get leds.radio` | *(ZephCore only)* Activity-LED mode: `tx`, `rx`, `all` or `off`. Appends `(no radio LED on this board)` where the board has neither a `lora-tx-led` nor a `lora-tx-pwm-led` alias |
 | `get leds.hb` | *(ZephCore only)* Heartbeat-LED mode: `all`, `hb`, `unread` or `off`. Appends `(no heartbeat LED on this board)` where the board has neither `led0` nor `led1` |
+| `get leds.brightness` | *(ZephCore only)* Brightness of a PWM-capable heartbeat/activity LED, `0` to `100` as a percentage. Boards without a `heartbeat-pwm-led` / `lora-tx-pwm-led` alias still report a value (nothing reads it) |
 | `get buzzer` | *(ZephCore only; room server only)* Buzzer/vibration mode as `<n> (<name>)`: `0 (silent)`, `1 (sound+vib)`, `2 (vibrate)`, `3 (sound)`. Compiled out on repeater builds (`#ifndef ZEPHCORE_REPEATER`) — a repeater answers `unknown config: buzzer`. |
 | `get agc.reset.interval` | Removed — replies `Removed - Automatic AGC reset is on`. Periodic AGC recalibration was deleted (it reset the noise floor to its unseeded sentinel on every fire). Use `set rxduty` to cut RX current. |
 | `get multi.acks` | Extra ACK transmit count (`0` or `1`) |
@@ -441,8 +442,9 @@ four radio parameters together, since they are one interop-critical set.
 | `set int.thresh <value>` | | Interference detection threshold |
 | `set buzzer <0\|1\|2\|3>` | or `off` / `on` / `vibrate` / `sound` | *(ZephCore only; room server only)* `0`/`off` silent, `1`/`on` sound + vibration, `2`/`vibrate` vibration only, `3`/`sound` sound only. Modes 2 and 3 need a vibration motor; without one the node replies `Error: no vibration motor on this board - use 0 or 1`. Applied live and persisted. Compiled out on repeater builds. |
 | `set leds <on\|off\|1\|0>` | default **on** | *(ZephCore only)* Master switch for every LED on the node, applied live and persisted: heartbeat, unread-message and LoRa TX-activity LEDs, plus the message and shutdown flashes. Works on every role, including headless repeaters where the TX LED is the only one that ever lights. Does **not** cover the display backlight, which is a separate UI brightness setting. |
-| `set leds.radio <tx\|rx\|all\|off>` | default **tx** | *(ZephCore only)* What the LoRa activity LED reacts to, applied live and persisted. `tx` lights it for the duration of each transmit (the behaviour before this setting existed), `rx` gives a 30 ms blink per valid packet received, `all` does both, `off` keeps it dark. Sits **below** `set leds` — the master switch off keeps it dark whatever this says. Only boards defining the `lora-tx-led` alias have this LED; elsewhere the value is stored but does nothing, and the reply says so. |
+| `set leds.radio <tx\|rx\|all\|off>` | default **tx** | *(ZephCore only)* What the LoRa activity LED reacts to, applied live and persisted. `tx` lights it for the duration of each transmit (the behaviour before this setting existed), `rx` gives a 30 ms blink per valid packet received, `all` does both, `off` keeps it dark. Sits **below** `set leds`: the master switch off keeps it dark whatever this says. Only boards defining a `lora-tx-led` or `lora-tx-pwm-led` alias have this LED; elsewhere the value is stored but does nothing, and the reply says so. |
 | `set leds.hb <hb\|unread\|all\|off>` | default **all** | *(ZephCore only)* What the heartbeat LED reacts to, applied live and persisted. `all` is the 4 s liveness tick that widens from 20 ms to 200 ms while messages are unread (the behaviour before this setting existed), `hb` never widens, `unread` stays dark until there are unread messages, `off` keeps it dark. Also sits below `set leds`. See the LED-topology notes below for what this does on single-LED boards. |
+| `set leds.brightness <0-100>` | default **100** | *(ZephCore only)* Brightness of a PWM-capable heartbeat/activity LED, applied live and persisted, `%` suffix accepted. Only boards defining a `heartbeat-pwm-led` or `lora-tx-pwm-led` alias have a dimmable LED; elsewhere the value is stored but has no effect. Also sits below `set leds`. |
 | `set agc.reset.interval <ms>` | Accepted, ignored | Removed — replies `Removed - Automatic AGC reset is on`. The prefs byte is still read and written so the on-flash layout stays byte-exact, but nothing acts on it. |
 | `set multi.acks <0\|1>` | | Enable extra ACK transmits |
 | `set path.hash.mode <mode>` | 0, 1, or 2 | Path hashing algorithm |
@@ -477,18 +479,27 @@ four radio parameters together, since they are one interop-critical set.
 
 ## Notes
 
-- **LED topology differs by board, and it changes what `leds.radio` / `leds.hb` can do.** Two DT aliases
-  decide it: `lora-tx-led` drives the radio activity LED, and `led0` (falling back to `led1`) drives the
-  heartbeat. Of the 35 boards in tree:
+- **LED topology differs by board, and it changes what `leds.radio` / `leds.hb` can do.** DT aliases
+  decide it: `lora-tx-led` or `lora-tx-pwm-led` drives the radio activity LED, and `led0` (falling back
+  to `led1`) drives the heartbeat. Of the 35 boards in tree:
   - **Separate pins (6)** — `rak4631`, `sensecap_solar`, `thinknode_m1`, `thinknode_m6`, `lilygo_techo`,
     `xiao_nrf52840`. Both settings are fully independent. `xiao_nrf52840` has three LEDs: blue heartbeat,
     green unread, red radio.
   - **One shared pin (8)** — `heltec_t114`, `heltec_t096`, `heltec_wireless_tracker_v2`, `ttgo_tbeam`,
     `gat562_30s`, `rak3401_1watt`, `rak_wismesh_tag`, `lilygo_timpulse_plus`. Here `lora-tx-led` **is** the
     heartbeat pin, so both settings drive one LED. Radio activity takes priority and the heartbeat yields
     while the radio holds the pin, so a transmit is never blanked mid-packet by the heartbeat's off-timer
-    (and vice versa). Use `set leds.hb off` for an unambiguous radio indicator.
-  - **No radio LED (20)** — including `wio_tracker_l1`, `t1000_e`, `meshtracker_x1`, Heltec V3/V4/V43 and
+    (and vice versa). Use `set leds.hb off` for an unambiguous radio indicator. `heltec_t096` and
+    `heltec_wireless_tracker_v2` also alias the same LED to `heartbeat-pwm-led`/`lora-tx-pwm-led`, so it is
+    dimmable with `leds.brightness`.
+  - **One shared PWM-only pin (1)**: `heltec_wifi_lora32_v43` has no plain `lora-tx-led`, only
+    `lora-tx-pwm-led` aliased to the same PWM LED as the heartbeat: a radio LED that exists only through
+    the PWM path, dimmable with `leds.brightness` like the boards above. On ESP32, a board in either PWM
+    category must not configure that pin as plain GPIO in `main()`, or the GPIO matrix takes the pin back
+    from the LEDC peripheral and the PWM output goes dark; `src/server_main_common.cpp` and
+    `app/main_observer.cpp` skip it automatically (`ZEPHCORE_HAS_PWM_SHARED_LED`) whenever a PWM LED alias
+    is present.
+  - **No radio LED (19)**: including `wio_tracker_l1`, `t1000_e`, `meshtracker_x1`, Heltec V3/V4 and
     both ProMicros. `set leds.radio` is accepted and stored (so the setting survives onto a board that does
     have the LED) but does nothing; the reply says `(no radio LED on this board)`.
   - **No heartbeat LED (1)** — `lilygo_t3s3` has `lora-tx-led` but neither `led0` nor `led1`, so `set leds.hb`

tests/catalog.json

@@ -374,7 +374,7 @@
     },
     {
       "id": "UNIT-PREFS-001",
-      "name": "Companion prefs encode to the documented 272-byte layout",
+      "name": "Companion prefs encode to the documented 273-byte layout",
       "source": "tests/unit/prefs_codec_tests.cpp"
     },
     {
@@ -399,7 +399,7 @@
     },
     {
       "id": "UNIT-PREFS-006",
-      "name": "Server prefs encode to the documented 311-byte layout",
+      "name": "Server prefs encode to the documented 312-byte layout",
       "source": "tests/unit/prefs_codec_tests.cpp"
     },
     {

tests/unit/prefs_codec_tests.cpp

@@ -13,7 +13,7 @@ namespace {
 struct Field { size_t file_off; size_t size; size_t struct_off; };
 #define F(off, member) { off, sizeof(NodePrefs::member), offsetof(NodePrefs, member) }
 
-// Companion /lfs/new_prefs, 272 bytes. Pads at 36-39 and 79.
+// Companion /lfs/new_prefs, 273 bytes. Pads at 36-39 and 79.
 const Field kCompanion[] = {
     F(0, airtime_factor), F(4, node_name), F(40, node_lat), F(48, node_lon), F(56, freq),
     F(60, sf), F(61, cr), F(62, client_repeat), F(63, manual_add_contacts), F(64, bw),
@@ -30,10 +30,10 @@ const Field kCompanion[] = {
     F(158, cad_busycap), F(159, adc_multiplier), F(163, extra_sf), F(166, v_contact_flags),
     F(167, fem_rxgain), F(168, display_rotate), F(169, input_rotate), F(170, cad_base),
     F(171, tz_offset), F(172, leds_radio_mode), F(173, leds_hb_mode), F(174, wifi_enabled),
-    F(175, wifi_ssid), F(208, wifi_pwd),
+    F(175, wifi_ssid), F(208, wifi_pwd), F(272, led_brightness),
 };
 
-// Server /lfs/repeater/prefs, 311 bytes. Offset 120 is leds_disabled as a
+// Server /lfs/repeater/prefs, 312 bytes. Offset 120 is leds_disabled as a
 // magic byte (checked separately); pads at 36-39, 79, 123, 127-151 (bridge),
 // 153-155.
 const Field kServer[] = {
@@ -50,7 +50,7 @@ const Field kServer[] = {
     F(295, flood_max_advert), F(296, meshtimesync), F(297, cad_auto), F(298, cad_offset),
     F(299, probe_interval), F(300, cad_busycap), F(301, extra_sf), F(304, fem_rxgain),
     F(305, display_rotate), F(306, input_rotate), F(307, cad_base), F(308, tz_offset),
-    F(309, leds_radio_mode), F(310, leds_hb_mode),
+    F(309, leds_radio_mode), F(310, leds_hb_mode), F(311, led_brightness),
 };
 #undef F
 
@@ -80,7 +80,7 @@ NodePrefs sample() {
     p.backoff_multiplier = 0.6f; p.allow_read_only = 1; p.multi_acks = 1;
     p.flood_max = 20; p.flood_max_unscoped = 10; p.flood_max_advert = 4;
     p.interference_threshold = 7; p.leds_disabled = 1; p.leds_radio_mode = LEDS_RADIO_RX;
-    p.leds_hb_mode = LEDS_HB_UNREAD; p.powersaving_enabled = 1; p.gps_enabled = 1;
+    p.leds_hb_mode = LEDS_HB_UNREAD; p.led_brightness = 42; p.powersaving_enabled = 1; p.gps_enabled = 1;
     p.gps_interval = 600; p.advert_loc_policy = ADVERT_LOC_SHARE; p.discovery_mod_timestamp = 123456;
     p.adc_multiplier = 1.25f; strcpy(p.owner_info, "owner info");
     p.rx_boost = 0; p.fem_rxgain = 0; p.rx_duty_cycle = 1;
@@ -125,7 +125,7 @@ NodePrefs expectShort(const NodePrefs &file_p, size_t len, const Field (&table)[
 
 }  // namespace
 
-TEST(prefs_companion_layout, "UNIT-PREFS-001", "Companion prefs encode to the documented 272-byte layout") {
+TEST(prefs_companion_layout, "UNIT-PREFS-001", "Companion prefs encode to the documented 273-byte layout") {
     NodePrefs p = sample();
     uint8_t buf[COMPANION_PREFS_SIZE + 8];
     std::memset(buf, 0xEE, sizeof(buf));
@@ -154,7 +154,7 @@ TEST(prefs_companion_short, "UNIT-PREFS-003", "Short companion files keep the ca
     // Every field boundary: each length the format has had ends on one.
     const size_t lens[] = { 91, 92, 93, 94, 95, 96, 127, 143, 144, 145, 146, 148, 150, 151,
                             152, 153, 155, 156, 157, 158, 159, 163, 166, 167, 168, 169, 170,
-                            171, 172, 173, 174, 175, 208, 272 };
+                            171, 172, 173, 174, 175, 208, 272, 273 };
     for (size_t len : lens) {
         NodePrefs got = defaults();
         CHECK(companionPrefsDecode(got, full, len));
@@ -215,7 +215,7 @@ TEST(prefs_companion_corrupt, "UNIT-PREFS-005", "Corrupt companion bytes fall ba
     CHECK(got.leds_radio_mode == 0);
 }
 
-TEST(prefs_server_layout, "UNIT-PREFS-006", "Server prefs encode to the documented 311-byte layout") {
+TEST(prefs_server_layout, "UNIT-PREFS-006", "Server prefs encode to the documented 312-byte layout") {
     NodePrefs p = sample();
     uint8_t buf[SERVER_PREFS_SIZE + 8];
     std::memset(buf, 0xEE, sizeof(buf));
@@ -248,7 +248,7 @@ TEST(prefs_server_short, "UNIT-PREFS-008", "Short server files keep the caller's
     uint8_t full[SERVER_PREFS_SIZE];
     serverPrefsEncode(p, full, sizeof(full));
     // Every length the format has had.
-    const size_t lens[] = { 290, 292, 294, 296, 297, 300, 301, 304, 305, 307, 308, 309, 311 };
+    const size_t lens[] = { 290, 292, 294, 296, 297, 300, 301, 304, 305, 307, 308, 309, 311, 312 };
     for (size_t len : lens) {
         NodePrefs got = defaults();
         serverPrefsDecode(got, full, len);

zephcore/adapters/board/ZephyrBoard.cpp

@@ -12,6 +12,7 @@
 #include <zephyr/sys/reboot.h>
 #include <zephyr/drivers/sensor.h>
 #include <zephyr/drivers/gpio.h>
+#include <zephyr/drivers/pwm.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -57,33 +58,51 @@
 #endif
 #endif
 
-/* LoRa radio activity LED (optional — defined per-board via DT alias).  Still
- * called tx_led after "set leds.radio" gave it an RX mode, because the DT alias
- * it comes from is named lora-tx-led on every board that has one. */
-#if DT_NODE_EXISTS(DT_ALIAS(lora_tx_led))
+/* LoRa activity LED, optional per board. The PWM alias wins over the GPIO one. */
+#if DT_NODE_EXISTS(DT_ALIAS(lora_tx_pwm_led))
+static const struct pwm_dt_spec tx_led_pwm = PWM_DT_SPEC_GET(DT_ALIAS(lora_tx_pwm_led));
+#define HAS_TX_LED_PWM 1
+#define HAS_TX_LED 0
+/* Initialised in tx_led_init() below, with the GPIO path. */
+#elif DT_NODE_EXISTS(DT_ALIAS(lora_tx_led))
 static const struct gpio_dt_spec tx_led =
 	GPIO_DT_SPEC_GET(DT_ALIAS(lora_tx_led), gpios);
+#define HAS_TX_LED_PWM 0
 #define HAS_TX_LED 1
 #else
+#define HAS_TX_LED_PWM 0
 #define HAS_TX_LED 0
 #endif
 
-/* True when this board wires the activity LED to the same pin as the heartbeat
- * (8 of the supported boards do).  Only those pay for the arbitration hold in
- * led_gate.c — everywhere else the two LEDs are independent and the calls
- * compile out.  led1 is checked as well because ui_common.c falls back to it
- * when a board has no led0. */
+/* Heartbeat and activity LED on one pin: only then is the arbitration hold in
+ * led_gate.c needed. led1 counts too, since ui_common.c falls back to it. */
 #if HAS_TX_LED && DT_NODE_EXISTS(DT_ALIAS(led0)) && \
 	DT_SAME_NODE(DT_ALIAS(led0), DT_ALIAS(lora_tx_led))
 #define ZEPHCORE_LED_PIN_SHARED 1
 #elif HAS_TX_LED && !DT_NODE_EXISTS(DT_ALIAS(led0)) && \
 	  DT_NODE_EXISTS(DT_ALIAS(led1)) && \
 	  DT_SAME_NODE(DT_ALIAS(led1), DT_ALIAS(lora_tx_led))
 #define ZEPHCORE_LED_PIN_SHARED 1
+/* Same for one PWM LED node shared by both (T096, Wireless Tracker V2). */
+#elif HAS_TX_LED_PWM && DT_NODE_EXISTS(DT_ALIAS(heartbeat_pwm_led)) && \
+      DT_SAME_NODE(DT_ALIAS(heartbeat_pwm_led), DT_ALIAS(lora_tx_pwm_led))
+#define ZEPHCORE_LED_PIN_SHARED 1
 #else
 #define ZEPHCORE_LED_PIN_SHARED 0
 #endif
 
+#if HAS_TX_LED_PWM
+static inline void tx_led_write(bool on)
+{
+	zephcore_led_pwm_write(&tx_led_pwm, on);
+}
+#elif HAS_TX_LED
+static inline void tx_led_write(bool on)
+{
+	gpio_pin_set_dt(&tx_led, on ? 1 : 0);
+}
+#endif
+
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(zephcore_board, CONFIG_ZEPHCORE_BOARD_LOG_LEVEL);
 
@@ -139,8 +158,8 @@ static const struct device *const pmic_charger_dev =
 #define HAS_PMIC_CHARGER 0
 #endif
 
-/* Initialize activity LED GPIO at boot */
-#if HAS_TX_LED
+/* Initialize activity LED (PWM or GPIO) at boot */
+#if HAS_TX_LED_PWM || HAS_TX_LED
 /* Width of the receive blink.  A transmit holds the LED for its whole airtime,
  * but a receive is a single edge — the packet is over by the time the driver
  * hands it up — so RX has to be a fixed one-shot.  30 ms is deliberately longer
@@ -165,17 +184,23 @@ static void rx_pulse_off_handler(struct k_work *work)
 	if (atomic_get(&s_tx_lit)) {
 		return;
 	}
-	gpio_pin_set_dt(&tx_led, 0);
+	tx_led_write(false);
 #if ZEPHCORE_LED_PIN_SHARED
 	zephcore_led_radio_hold_pin(false);
 #endif
 }
 
 static int tx_led_init(void)
 {
+#if HAS_TX_LED_PWM
+	if (device_is_ready(tx_led_pwm.dev)) {
+		pwm_set_pulse_dt(&tx_led_pwm, 0);  /* start dark, same as GPIO_OUTPUT_INACTIVE */
+	}
+#else
 	if (gpio_is_ready_dt(&tx_led)) {
 		gpio_pin_configure_dt(&tx_led, GPIO_OUTPUT_INACTIVE);
 	}
+#endif
 	k_work_init_delayable(&s_rx_pulse_off, rx_pulse_off_handler);
 	return 0;
 }
@@ -364,12 +389,12 @@ const char *ZephyrBoard::getManufacturerName() const
 
 void ZephyrBoard::onBeforeTransmit()
 {
-#if HAS_TX_LED
 	/* Honour the LED master gate ("set leds off") and then the activity mode
 	 * ("set leds.radio"). On a headless repeater this is the only LED that ever
 	 * lights, so both have to be checked here and not just in the UI layer.
 	 * onAfterTransmit() still clears the pin unconditionally, so a gate or mode
 	 * flipped mid-transmit can't strand it lit. */
+#if HAS_TX_LED_PWM || HAS_TX_LED
 	uint8_t mode = zephcore_leds_radio_mode();
 	if (!zephcore_leds_disabled() &&
 	    (mode == LEDS_RADIO_TX || mode == LEDS_RADIO_ALL)) {
@@ -380,16 +405,16 @@ void ZephyrBoard::onBeforeTransmit()
 #if ZEPHCORE_LED_PIN_SHARED
 		zephcore_led_radio_hold_pin(true);
 #endif
-		gpio_pin_set_dt(&tx_led, 1);
+		tx_led_write(true);
 	}
 #endif
 }
 
 void ZephyrBoard::onAfterTransmit()
 {
-#if HAS_TX_LED
+#if HAS_TX_LED_PWM || HAS_TX_LED
 	atomic_set(&s_tx_lit, 0);
-	gpio_pin_set_dt(&tx_led, 0);
+	tx_led_write(false);
 #if ZEPHCORE_LED_PIN_SHARED
 	zephcore_led_radio_hold_pin(false);
 #endif
@@ -398,7 +423,7 @@ void ZephyrBoard::onAfterTransmit()
 
 void ZephyrBoard::onPacketReceived()
 {
-#if HAS_TX_LED
+#if HAS_TX_LED_PWM || HAS_TX_LED
 	uint8_t mode = zephcore_leds_radio_mode();
 	if (zephcore_leds_disabled() ||
 	    (mode != LEDS_RADIO_RX && mode != LEDS_RADIO_ALL)) {
@@ -414,7 +439,7 @@ void ZephyrBoard::onPacketReceived()
 #if ZEPHCORE_LED_PIN_SHARED
 	zephcore_led_radio_hold_pin(true);
 #endif
-	gpio_pin_set_dt(&tx_led, 1);
+	tx_led_write(true);
 	/* Reschedule rather than schedule: back-to-back packets should extend the
 	 * blink, not have the first one's handler cut the second one short. */
 	k_work_reschedule(&s_rx_pulse_off, K_MSEC(RX_PULSE_MS));

zephcore/app/main_observer.cpp

@@ -44,7 +44,15 @@ LOG_MODULE_REGISTER(zephcore_observer_main, CONFIG_ZEPHCORE_MAIN_LOG_LEVEL);
 
 /* ========== LED (optional) ========== */
 
-#if DT_NODE_HAS_PROP(DT_ALIAS(led0), gpios)
+/* True when a board aliases its heartbeat or TX-activity LED to a PWM node.
+ * On ESP32, configuring led0 as plain GPIO after the PWM driver has already
+ * routed the pin takes the pin back from the LEDC peripheral (the GPIO
+ * matrix only serves one signal at a time), so on those boards led0 must be
+ * left to the PWM driver instead of reconfigured here. */
+#define ZEPHCORE_HAS_PWM_SHARED_LED \
+	(DT_NODE_EXISTS(DT_ALIAS(heartbeat_pwm_led)) || DT_NODE_EXISTS(DT_ALIAS(lora_tx_pwm_led)))
+
+#if DT_NODE_HAS_PROP(DT_ALIAS(led0), gpios) && !ZEPHCORE_HAS_PWM_SHARED_LED
 #include <zephyr/drivers/gpio.h>
 #define LED0_NODE DT_ALIAS(led0)
 static const struct gpio_dt_spec led0 = GPIO_DT_SPEC_GET(LED0_NODE, gpios);
@@ -320,7 +328,7 @@ int main(void)
 	LOG_INF("=== ZephCore Observer starting ===");
 
 	/* Configure LED */
-#if DT_NODE_HAS_PROP(DT_ALIAS(led0), gpios)
+#if DT_NODE_HAS_PROP(DT_ALIAS(led0), gpios) && !ZEPHCORE_HAS_PWM_SHARED_LED
 	if (gpio_is_ready_dt(&led0)) {
 		gpio_pin_configure_dt(&led0, GPIO_OUTPUT_INACTIVE);
 	}

zephcore/boards/esp32/heltec_wifi_lora32_v43/board.conf

@@ -28,3 +28,6 @@ CONFIG_ZEPHCORE_DEFAULT_TX_POWER_DBM=12
 # board.overlay): the default 500ms double-press confirm window (shutdown/
 # DFU/offgrid) is too short for two ~1s holds, see Kconfig help text.
 CONFIG_ZEPHCORE_UI_CONFIRM_WINDOW_MS=3000
+
+# PWM for LED brightness. Kept here, not in the defconfig: the defconfig is shared with mcuboot, which fails to link with it.
+CONFIG_PWM=y

zephcore/boards/esp32/heltec_wifi_lora32_v43/heltec_wifi_lora32_v43_procpu.dts

@@ -47,6 +47,13 @@
 		led0 = &led0;
 		pwm-0 = &ledc0;
 		pwm-led0 = &pwm_led_white;
+		/* Single physical LED, shared between the heartbeat and LoRa TX
+		 * activity roles (same node aliased twice), same pattern as T096 and
+		 * Wireless Tracker V2 -- see helpers/ui/ui_common.c and
+		 * adapters/board/ZephyrBoard.cpp (ZEPHCORE_LED_PIN_SHARED covers the
+		 * arbitration between the two roles automatically). */
+		heartbeat-pwm-led = &pwm_led_white;
+		lora-tx-pwm-led = &pwm_led_white;
 		uart-0 = &uart0;
 		i2c-0 = &i2c0;
 		lora0 = &lora0;