diff --git a/Makefile.platform.sample b/Makefile.platform.sample
index cf51ab424..c07ff6448 100644
--- a/Makefile.platform.sample
+++ b/Makefile.platform.sample
@@ -3,7 +3,7 @@
 
 # By default PM3 RDV4 image is generated.
 # Comment the line below and uncomment further down according to which device you have
-PLATFORM=PM3RDV4
+PLATFORM=PM5
 
 # For PM3 RDV1, RDV2, Easy or rysccorps etc
 # uncomment the line below
diff --git a/armsrc/appmain.c b/armsrc/appmain.c
index 37b12b80b..644918e84 100644
--- a/armsrc/appmain.c
+++ b/armsrc/appmain.c
@@ -30,6 +30,7 @@
 #include "fpga_apis.h"
 #include "rssi_apis.h"
 #include "rgb_apis.h"
+#include "gpio_apis.h"    // gpio_vusb_setup / Gpio_VUSB_Read (USB-present detection)
 #include "string.h"
 #include "printf.h"
 #include "legicrf.h"
@@ -397,6 +398,56 @@ static void bwm_detect_and_init(void) {
 
 #endif // WITH_BWM_STATUS
 
+#ifdef WITH_PM5_PWR_LED
+// "Alive on battery" indicator. When the PM5 runs on battery (USB unplugged) it
+// otherwise gives no sign it is on, so users leave it draining. This lights the
+// antenna RGB a dim green while on battery, and turns it off when on USB (where the
+// cable already signals power). Throttled + edge-triggered to avoid I2C spam and to
+// yield the RGB to hf/lf tune (which sets g_rgb_external while it owns the LED).
+#ifndef PM5_PWR_LED_PERIOD_MS
+#define PM5_PWR_LED_PERIOD_MS  1000   // re-evaluate at most once a second
+#endif
+
+// Set by CMD_PM5_RGB_SET so the indicator backs off while tune controls the RGB.
+volatile bool g_rgb_external = false;
+
+static bool s_pwr_led_setup = false;
+
+static void bwm_power_led_check(void) {
+    static uint32_t last_tick = 0;
+    static int last_state = -1;   // -1 unknown, 0 = off/USB, 1 = green/battery
+
+    if ((last_tick != 0) && (GetTickCountDelta(last_tick) < PM5_PWR_LED_PERIOD_MS)) {
+        return;
+    }
+    last_tick = GetTickCount();
+
+    // While tune (or any external RGB user) owns the LED, do nothing and force a
+    // refresh next time it is released.
+    if (g_rgb_external) {
+        last_state = -1;
+        return;
+    }
+
+    if (s_pwr_led_setup == false) {
+        gpio_vusb_setup();
+        s_pwr_led_setup = true;
+    }
+
+    int on_battery = (Gpio_VUSB_Read() == false) ? 1 : 0;
+    if (on_battery == last_state) {
+        return;   // edge-triggered: only write RGB when the state changes
+    }
+    last_state = on_battery;
+
+    if (on_battery) {
+        RgbLedSet(0, 8, 0);   // dim green: alive, on battery
+    } else {
+        RgbLedSet(0, 0, 0);   // on USB: off (cable already signals power)
+    }
+}
+#endif // WITH_PM5_PWR_LED
+
 #ifdef WITH_LCD
 #include "LCD_disabled.h"
 #endif
@@ -3960,6 +4011,11 @@ static void PacketReceived(PacketCommandNG *packet) {
             } PACKED;
             struct p *payload = (struct p *)packet->data.asBytes;
             RgbLedSet(payload->r, payload->g, payload->b);
+#ifdef WITH_PM5_PWR_LED
+            // tune (or any external RGB user) now owns the LED; back the power
+            // indicator off. A non-zero colour claims it; all-zero releases it.
+            g_rgb_external = (payload->r || payload->g || payload->b);
+#endif
             reply_ng(CMD_PM5_RGB_SET, PM3_SUCCESS, NULL, 0);
             break;
         }
@@ -4073,6 +4129,10 @@ void __attribute__((noreturn)) AppMain(void) {
     for (;;) {
         WDT_HIT();
 
+#ifdef WITH_PM5_PWR_LED
+        bwm_power_led_check();
+#endif
+
         if (*_stack_start != 0xdeadbeef) {
             Dbprintf("DEBUG: increase stack size, currently " _YELLOW_("%d") " bytes", (uint32_t)_stack_end - (uint32_t)_stack_start);
             Dbprintf("Stack overflow detected");
diff --git a/common_arm/Makefile.hal b/common_arm/Makefile.hal
index e94159882..a3f62e37d 100644
--- a/common_arm/Makefile.hal
+++ b/common_arm/Makefile.hal
@@ -178,7 +178,7 @@ else ifeq ($(PLATFORM),PM5)
     FPGA_BITSTREAMS = fpga_pm3_hf.bit # TODO DXL 虽然可以不把打包比特流，但是还是得把FPGA的版本信息给生成，让EXE依赖。
     SKIP_FPGA_EMBED = true # important!!! disable the fpga bit files pack to arm!
     SKIP_COMPRESSION = true # Skip data section compress. The new mcu has enough flash space.
-    PLATFORM_DEFS = -DWITH_FLASH -DPM5 -DCHIP_AT32F435_37 -DWITH_BWM_STATUS # TODO 暂时不要编译i2c -DWITH_SMARTCARD
+    PLATFORM_DEFS = -DWITH_FLASH -DPM5 -DCHIP_AT32F435_37 -DWITH_BWM_STATUS -DWITH_PM5_PWR_LED # TODO 暂时不要编译i2c -DWITH_SMARTCARD
                     # -DWITH_BWM_LOWBATT_BEEP ===== if you want audible alert ====
     PLTNAME = Proxmark5
     PLATFORM_FPGA = GW1NR-LV2MG49GC6/i5