StackRduino
diff --git a/‎ports/esp8266/common-hal/digitalio/DigitalInOut.c‎
Lines changed: 41 additions & 7 deletions b/‎ports/esp8266/common-hal/digitalio/DigitalInOut.c‎
Lines changed: 41 additions & 7 deletions
@@ -33,11 +33,21 @@
 #include "py/mphal.h"
 
 #include "shared-bindings/digitalio/DigitalInOut.h"
+#include "common-hal/microcontroller/Pin.h"
+
+extern volatile bool gpio16_in_use;
 
 digitalinout_result_t common_hal_digitalio_digitalinout_construct(
         digitalio_digitalinout_obj_t* self, const mcu_pin_obj_t* pin) {
     self->pin = pin;
-    PIN_FUNC_SELECT(self->pin->peripheral, self->pin->gpio_function);
+    if (self->pin->gpio_number == 16) {
+        WRITE_PERI_REG(PAD_XPD_DCDC_CONF, (READ_PERI_REG(PAD_XPD_DCDC_CONF) & 0xffffffbc) | 1); 	// mux configuration for XPD_DCDC and rtc_gpio0 connection
+        WRITE_PERI_REG(RTC_GPIO_CONF, READ_PERI_REG(RTC_GPIO_CONF) & ~1);	//mux configuration for out enable
+        WRITE_PERI_REG(RTC_GPIO_ENABLE, READ_PERI_REG(RTC_GPIO_ENABLE) & ~1);	//out disable
+        gpio16_in_use = true;
+    } else {
+        PIN_FUNC_SELECT(self->pin->peripheral, self->pin->gpio_function);
+    }
     return DIGITALINOUT_OK;
 }
 
@@ -54,6 +64,8 @@ void common_hal_digitalio_digitalinout_deinit(digitalio_digitalinout_obj_t* self
         gpio_output_set(0x0, 0x0, 0x0, pin_mask);
         PIN_FUNC_SELECT(self->pin->peripheral, 0);
         PIN_PULLUP_DIS(self->pin->peripheral);
+    } else {
+        gpio16_in_use = false;
     }
     self->pin = mp_const_none;
 }
@@ -96,6 +108,23 @@ digitalio_direction_t common_hal_digitalio_digitalinout_get_direction(
 
 void common_hal_digitalio_digitalinout_set_value(
         digitalio_digitalinout_obj_t* self, bool value) {
+    if (self->pin->gpio_number == 16) {
+        if (self->open_drain) {
+                // configure GPIO16 as input with output register holding 0
+                WRITE_PERI_REG(PAD_XPD_DCDC_CONF, (READ_PERI_REG(PAD_XPD_DCDC_CONF) & 0xffffffbc) | 1);
+                WRITE_PERI_REG(RTC_GPIO_CONF, READ_PERI_REG(RTC_GPIO_CONF) & ~1);
+                WRITE_PERI_REG(RTC_GPIO_ENABLE, (READ_PERI_REG(RTC_GPIO_ENABLE) & ~1)); // input
+                WRITE_PERI_REG(RTC_GPIO_OUT, (READ_PERI_REG(RTC_GPIO_OUT) & ~1)); // out=0
+                return;
+        } else {
+            int out_en = self->output;
+            WRITE_PERI_REG(PAD_XPD_DCDC_CONF, (READ_PERI_REG(PAD_XPD_DCDC_CONF) & 0xffffffbc) | 1);
+            WRITE_PERI_REG(RTC_GPIO_CONF, READ_PERI_REG(RTC_GPIO_CONF) & ~1);
+            WRITE_PERI_REG(RTC_GPIO_ENABLE, (READ_PERI_REG(RTC_GPIO_ENABLE) & ~1) | out_en);
+            WRITE_PERI_REG(RTC_GPIO_OUT, (READ_PERI_REG(RTC_GPIO_OUT) & ~1) | value);
+            return;
+        }
+    }
     if (value) {
         if (self->open_drain) {
             // Disable output.
@@ -125,11 +154,15 @@ bool common_hal_digitalio_digitalinout_get_value(
         }
         return GPIO_INPUT_GET(self->pin->gpio_number);
     } else {
-        uint32_t pin_mask = 1 << self->pin->gpio_number;
-        if (self->open_drain && ((*PIN_DIR) & pin_mask) == 0) {
-            return true;
+        if (self->pin->gpio_number == 16) {
+            return READ_PERI_REG(RTC_GPIO_OUT) & 1;
         } else {
-            return ((*PIN_OUT) & pin_mask) != 0;
+            uint32_t pin_mask = 1 << self->pin->gpio_number;
+            if (self->open_drain && ((*PIN_DIR) & pin_mask) == 0) {
+                return true;
+            } else {
+                return ((*PIN_OUT) & pin_mask) != 0;
+            }
         }
     }
 }
@@ -163,8 +196,9 @@ void common_hal_digitalio_digitalinout_set_pull(
         return;
     }
     if (self->pin->gpio_number == 16) {
-        nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError,
-            "Pin does not support pull."));
+        // PULL_DOWN is the only hardware pull direction available on GPIO16
+        // since we don't support pull down, just return without attempting
+        // to set pull (which won't work anyway).
         return;
     }
     if (pull == PULL_NONE) {