micropython · meirarmon · Jun 20, 2025
diff --git a/docs/library/machine.rst b/docs/library/machine.rst
@@ -171,6 +171,13 @@ Power related functions
 
    Availability: ESP32, WiPy.
 
+.. function:: wake_pins()
+
+   Returns the GPIO pin numbers of those pins which caused wakeup from deep sleep as a
+   tuple of integers.
+
+   Availability: ESP32.
+
 Miscellaneous functions
 -----------------------
 

diff --git a/ports/esp32/modmachine.c b/ports/esp32/modmachine.c
@@ -79,6 +79,7 @@
     { MP_ROM_QSTR(MP_QSTR_TIMER_WAKE), MP_ROM_INT(ESP_SLEEP_WAKEUP_TIMER) }, \
     { MP_ROM_QSTR(MP_QSTR_TOUCHPAD_WAKE), MP_ROM_INT(ESP_SLEEP_WAKEUP_TOUCHPAD) }, \
     { MP_ROM_QSTR(MP_QSTR_ULP_WAKE), MP_ROM_INT(ESP_SLEEP_WAKEUP_ULP) }, \
+    { MP_ROM_QSTR(MP_QSTR_wake_pins), MP_ROM_PTR(&machine_wake_pins_obj) }, \
 
 typedef enum {
     MP_PWRON_RESET = 1,
@@ -254,6 +255,40 @@ static mp_obj_t machine_wake_reason(size_t n_args, const mp_obj_t *pos_args, mp_
 }
 static MP_DEFINE_CONST_FUN_OBJ_KW(machine_wake_reason_obj, 0,  machine_wake_reason);
 
+static mp_obj_t machine_wake_pins(void) {
+    uint64_t status = 0;
+    int len, index;
+    mp_obj_t *tuple = NULL;
+
+    // There will be only one wake-up source, so it is OK to logically OR all the
+    // wake-up source statuses.
+    #if SOC_GPIO_SUPPORT_DEEPSLEEP_WAKEUP && SOC_DEEP_SLEEP_SUPPORTED
+    status |= esp_sleep_get_gpio_wakeup_status();
+    #endif
+
+    #if SOC_PM_SUPPORT_EXT1_WAKEUP && SOC_RTCIO_PIN_COUNT > 0
+    status |= esp_sleep_get_ext1_wakeup_status();
+    #endif
+
+    // Only a few (~8) pins might cause wakeup.
+    // Therefore, we don't allocate 64*4 = 256 bytes on the stack and calculate the
+    // required space in a first pass.
+    for (index = 0, len = 0; index < 64; index++) {
+        len += (status & ((uint64_t)1 << index)) ? 1 : 0;
+    }
+    if (len) {
+        tuple = alloca(len * sizeof(*tuple));
+
+        for (index = 0, len = 0; index < 64; index++) {
+            if (status & ((uint64_t)1 << index)) {
+                tuple[len++] = MP_OBJ_NEW_SMALL_INT(index);
+            }
+        }
+    }
+    return mp_obj_new_tuple(len, tuple);
+}
+static MP_DEFINE_CONST_FUN_OBJ_0(machine_wake_pins_obj, machine_wake_pins);
+
 MP_NORETURN static void mp_machine_reset(void) {
     esp_restart();
 }