Add interrupt support to GPIO binary sensors (#9115)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

esphome/components/gpio/binary_sensor/__init__.py

@@ -10,11 +10,24 @@ GPIOBinarySensor = gpio_ns.class_(
     "GPIOBinarySensor", binary_sensor.BinarySensor, cg.Component
 )
 
+CONF_USE_INTERRUPT = "use_interrupt"
+CONF_INTERRUPT_TYPE = "interrupt_type"
+
+INTERRUPT_TYPES = {
+    "RISING": gpio_ns.INTERRUPT_RISING_EDGE,
+    "FALLING": gpio_ns.INTERRUPT_FALLING_EDGE,
+    "ANY": gpio_ns.INTERRUPT_ANY_EDGE,
+}
+
 CONFIG_SCHEMA = (
     binary_sensor.binary_sensor_schema(GPIOBinarySensor)
     .extend(
         {
             cv.Required(CONF_PIN): pins.gpio_input_pin_schema,
+            cv.Optional(CONF_USE_INTERRUPT, default=True): cv.boolean,
+            cv.Optional(CONF_INTERRUPT_TYPE, default="ANY"): cv.enum(
+                INTERRUPT_TYPES, upper=True
+            ),
         }
     )
     .extend(cv.COMPONENT_SCHEMA)
@@ -27,3 +40,7 @@ async def to_code(config):
 
     pin = await cg.gpio_pin_expression(config[CONF_PIN])
     cg.add(var.set_pin(pin))
+
+    cg.add(var.set_use_interrupt(config[CONF_USE_INTERRUPT]))
+    if config[CONF_USE_INTERRUPT]:
+        cg.add(var.set_interrupt_type(config[CONF_INTERRUPT_TYPE]))

esphome/components/gpio/binary_sensor/gpio_binary_sensor.cpp

@@ -6,17 +6,91 @@ namespace gpio {
 
 static const char *const TAG = "gpio.binary_sensor";
 
+void IRAM_ATTR GPIOBinarySensorStore::gpio_intr(GPIOBinarySensorStore *arg) {
+  bool new_state = arg->isr_pin_.digital_read();
+  if (new_state != arg->last_state_) {
+    arg->state_ = new_state;
+    arg->last_state_ = new_state;
+    arg->changed_ = true;
+    // Wake up the component from its disabled loop state
+    if (arg->component_ != nullptr) {
+      arg->component_->enable_loop_soon_any_context();
+    }
+  }
+}
+
+void GPIOBinarySensorStore::setup(InternalGPIOPin *pin, gpio::InterruptType type, Component *component) {
+  pin->setup();
+  this->isr_pin_ = pin->to_isr();
+  this->component_ = component;
+
+  // Read initial state
+  this->last_state_ = pin->digital_read();
+  this->state_ = this->last_state_;
+
+  // Attach interrupt - from this point on, any changes will be caught by the interrupt
+  pin->attach_interrupt(&GPIOBinarySensorStore::gpio_intr, this, type);
+}
+
 void GPIOBinarySensor::setup() {
+  if (this->use_interrupt_ && !this->pin_->is_internal()) {
+    ESP_LOGD(TAG, "GPIO is not internal, falling back to polling mode");
+    this->use_interrupt_ = false;
+  }
+
+  if (this->use_interrupt_) {
+    auto *internal_pin = static_cast<InternalGPIOPin *>(this->pin_);
+    this->store_.setup(internal_pin, this->interrupt_type_, this);
+    this->publish_initial_state(this->store_.get_state());
+  } else {
     this->pin_->setup();
     this->publish_initial_state(this->pin_->digital_read());
   }
+}
 
 void GPIOBinarySensor::dump_config() {
   LOG_BINARY_SENSOR("", "GPIO Binary Sensor", this);
   LOG_PIN("  Pin: ", this->pin_);
+  const char *mode = this->use_interrupt_ ? "interrupt" : "polling";
+  ESP_LOGCONFIG(TAG, "  Mode: %s", mode);
+  if (this->use_interrupt_) {
+    const char *interrupt_type;
+    switch (this->interrupt_type_) {
+      case gpio::INTERRUPT_RISING_EDGE:
+        interrupt_type = "RISING_EDGE";
+        break;
+      case gpio::INTERRUPT_FALLING_EDGE:
+        interrupt_type = "FALLING_EDGE";
+        break;
+      case gpio::INTERRUPT_ANY_EDGE:
+        interrupt_type = "ANY_EDGE";
+        break;
+      default:
+        interrupt_type = "UNKNOWN";
+        break;
+    }
+    ESP_LOGCONFIG(TAG, "  Interrupt Type: %s", interrupt_type);
+  }
 }
 
-void GPIOBinarySensor::loop() { this->publish_state(this->pin_->digital_read()); }
+void GPIOBinarySensor::loop() {
+  if (this->use_interrupt_) {
+    if (this->store_.is_changed()) {
+      // Clear the flag immediately to minimize the window where we might miss changes
+      this->store_.clear_changed();
+      // Read the state and publish it
+      // Note: If the ISR fires between clear_changed() and get_state(), that's fine -
+      // we'll process the new change on the next loop iteration
+      bool state = this->store_.get_state();
+      this->publish_state(state);
+    } else {
+      // No changes, disable the loop until the next interrupt
+      this->disable_loop();
+    }
+  } else {
+    this->publish_state(this->pin_->digital_read());
+  }
+}
 
 float GPIOBinarySensor::get_setup_priority() const { return setup_priority::HARDWARE; }
 

esphome/components/gpio/binary_sensor/gpio_binary_sensor.h

@@ -2,14 +2,51 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/hal.h"
+#include "esphome/core/helpers.h"
 #include "esphome/components/binary_sensor/binary_sensor.h"
 
 namespace esphome {
 namespace gpio {
 
+// Store class for ISR data (no vtables, ISR-safe)
+class GPIOBinarySensorStore {
+ public:
+  void setup(InternalGPIOPin *pin, gpio::InterruptType type, Component *component);
+
+  static void gpio_intr(GPIOBinarySensorStore *arg);
+
+  bool get_state() const {
+    // No lock needed: state_ is atomically updated by ISR
+    // Volatile ensures we read the latest value
+    return this->state_;
+  }
+
+  bool is_changed() const {
+    // Simple read of volatile bool - no clearing here
+    return this->changed_;
+  }
+
+  void clear_changed() {
+    // Separate method to clear the flag
+    this->changed_ = false;
+  }
+
+ protected:
+  ISRInternalGPIOPin isr_pin_;
+  volatile bool state_{false};
+  volatile bool last_state_{false};
+  volatile bool changed_{false};
+  Component *component_{nullptr};  // Pointer to the component for enable_loop_soon_any_context()
+};
+
 class GPIOBinarySensor : public binary_sensor::BinarySensor, public Component {
  public:
+  // No destructor needed: ESPHome components are created at boot and live forever.
+  // Interrupts are only detached on reboot when memory is cleared anyway.
+
   void set_pin(GPIOPin *pin) { pin_ = pin; }
+  void set_use_interrupt(bool use_interrupt) { use_interrupt_ = use_interrupt; }
+  void set_interrupt_type(gpio::InterruptType type) { interrupt_type_ = type; }
   // ========== INTERNAL METHODS ==========
   // (In most use cases you won't need these)
   /// Setup pin
@@ -22,6 +59,9 @@ class GPIOBinarySensor : public binary_sensor::BinarySensor, public Component {
 
  protected:
   GPIOPin *pin_;
+  bool use_interrupt_{true};
+  gpio::InterruptType interrupt_type_{gpio::INTERRUPT_ANY_EDGE};
+  GPIOBinarySensorStore store_;
 };
 
 }  // namespace gpio