diff --git a/firmware/src_simtrace/wwan_led.c b/firmware/src_simtrace/wwan_led.c
new file mode 100644
index 0000000..3bae0ff
--- /dev/null
+++ b/firmware/src_simtrace/wwan_led.c
@@ -0,0 +1,80 @@
+/* Code to read/track the status of the WWAN LEDs of attached modems
+ *
+ * Depending on the board this is running on,  it might be possible
+ * for the controller to read the status of the WWAN LED output lines of
+ * the cellular modem.  If the board supports this, it sets the
+ * PIN_WWAN1 and/or PIN_WWAN2 defines in its board.h file.
+ */
+
+#include "board.h"
+#include "wwan_led.h"
+
+#ifdef PIN_WWAN1
+static const Pin pin_wwan1 = PIN_WWAN1;
+
+static void wwan1_irqhandler(const Pin *pPin)
+{
+	int active = wwan_led_active(1);
+
+	TRACE_INFO("WWAN1 LED %u\r\n", active);
+
+	/* TODO: notify host via USB */
+}
+#endif
+
+#ifdef PIN_WWAN2
+static const Pin pin_wwan2 = PIN_WWAN2;
+
+static void wwan2_irqhandler(const Pin *pPin)
+{
+	int active = wwan_led_active(2);
+	TRACE_INFO("WWAN2 LED %u\r\n", active);
+
+	/* TODO: notify host via USB */
+}
+#endif
+
+/* determine if a tiven WWAN led is currently active or not */
+int wwan_led_active(int wwan)
+{
+	const Pin *pin;
+	int active;
+
+	switch (wwan) {
+#ifdef PIN_WWAN1
+	case 1:
+		pin = &pin_wwan1;
+		break;
+#endif
+#ifdef PIN_WWAN2
+	case 2:
+		pin = &pin_wwan2;
+		break;
+#endif
+	default:
+		return -1;
+	}
+
+	active = PIO_Get(&pin_wwan1) ? 0 : 1;
+	return active;
+}
+
+int wwan_led_init(void)
+{
+	int num_leds = 0;
+
+#ifdef PIN_WWAN1
+	PIO_Configure(&pin_wwan1, 1);
+	PIO_ConfigureIt(&pin_wwan1, wwan1_irqhandler);
+	PIO_EnableIt(&pin_wwan1);
+	num_leds++;
+#endif
+
+#ifdef PIN_WWAN2
+	PIO_Configure(&pin_wwan2, 1);
+	PIO_ConfigureIt(&pin_wwan2, wwan2_irqhandler);
+	PIO_EnableIt(&pin_wwan2);
+	num_leds++;
+#endif
+	return num_leds;
+}