From 79fe3de912d13d52fd66719c16792903f2de3d4f Mon Sep 17 00:00:00 2001 From: "J. Nick Koston" Date: Sat, 4 Apr 2026 08:22:37 -1000 Subject: [PATCH] [pcf8574][pca9554] Add optional interrupt pin to eliminate polling Add interrupt_pin config option to PCF8574 and PCA9554 GPIO expander components. When configured, the component disables its loop and only wakes on interrupt, eliminating continuous I2C polling when no pins have changed state. --- esphome/components/pca9554/__init__.py | 4 ++++ esphome/components/pca9554/pca9554.cpp | 17 ++++++++++++++--- esphome/components/pca9554/pca9554.h | 5 ++++- esphome/components/pcf8574/__init__.py | 4 ++++ esphome/components/pcf8574/pcf8574.cpp | 15 ++++++++++++++- esphome/components/pcf8574/pcf8574.h | 5 ++++- 6 files changed, 44 insertions(+), 6 deletions(-) diff --git a/esphome/components/pca9554/__init__.py b/esphome/components/pca9554/__init__.py index 626b08a378..99b812b33b 100644 --- a/esphome/components/pca9554/__init__.py +++ b/esphome/components/pca9554/__init__.py @@ -5,6 +5,7 @@ import esphome.config_validation as cv from esphome.const import ( CONF_ID, CONF_INPUT, + CONF_INTERRUPT_PIN, CONF_INVERTED, CONF_MODE, CONF_NUMBER, @@ -29,6 +30,7 @@ CONFIG_SCHEMA = ( { cv.Required(CONF_ID): cv.declare_id(PCA9554Component), cv.Optional(CONF_PIN_COUNT, default=8): cv.one_of(4, 8, 16), + cv.Optional(CONF_INTERRUPT_PIN): pins.internal_gpio_input_pin_schema, } ) .extend(cv.COMPONENT_SCHEMA) @@ -43,6 +45,8 @@ async def to_code(config): cg.add(var.set_pin_count(config[CONF_PIN_COUNT])) await cg.register_component(var, config) await i2c.register_i2c_device(var, config) + if interrupt_pin := config.get(CONF_INTERRUPT_PIN): + cg.add(var.set_interrupt_pin(await cg.gpio_pin_expression(interrupt_pin))) def validate_mode(value): diff --git a/esphome/components/pca9554/pca9554.cpp b/esphome/components/pca9554/pca9554.cpp index adc7bc0fb5..96a65fae3d 100644 --- a/esphome/components/pca9554/pca9554.cpp +++ b/esphome/components/pca9554/pca9554.cpp @@ -34,12 +34,22 @@ void PCA9554Component::setup() { this->read_inputs_(); ESP_LOGD(TAG, "Initialization complete. Warning: %d, Error: %d", this->status_has_warning(), this->status_has_error()); -} + if (this->interrupt_pin_ != nullptr) { + this->interrupt_pin_->setup(); + this->interrupt_pin_->attach_interrupt(&PCA9554Component::gpio_intr, this, gpio::INTERRUPT_FALLING_EDGE); + // With interrupt pin, only run loop when interrupt fires + this->disable_loop(); + } +} +void IRAM_ATTR PCA9554Component::gpio_intr(PCA9554Component *arg) { arg->enable_loop_soon_any_context(); } void PCA9554Component::loop() { - // Invalidate the cache at the start of each loop. - // The actual read will happen on demand when digital_read() is called + // Invalidate the cache so the next digital_read() triggers a fresh I2C read this->reset_pin_cache_(); + if (this->interrupt_pin_ != nullptr) { + // Interrupt-driven: disable loop until next interrupt fires + this->disable_loop(); + } } void PCA9554Component::dump_config() { @@ -47,6 +57,7 @@ void PCA9554Component::dump_config() { "PCA9554:\n" " I/O Pins: %d", this->pin_count_); + LOG_PIN(" Interrupt Pin: ", this->interrupt_pin_); LOG_I2C_DEVICE(this) if (this->is_failed()) { ESP_LOGE(TAG, ESP_LOG_MSG_COMM_FAIL); diff --git a/esphome/components/pca9554/pca9554.h b/esphome/components/pca9554/pca9554.h index 1d877f9ce2..f33f9d4592 100644 --- a/esphome/components/pca9554/pca9554.h +++ b/esphome/components/pca9554/pca9554.h @@ -16,7 +16,6 @@ class PCA9554Component : public Component, /// Check i2c availability and setup masks void setup() override; - /// Invalidate cache at start of each loop void loop() override; /// Helper function to set the pin mode of a pin. void pin_mode(uint8_t pin, gpio::Flags flags); @@ -26,8 +25,11 @@ class PCA9554Component : public Component, void dump_config() override; void set_pin_count(size_t pin_count) { this->pin_count_ = pin_count; } + void set_interrupt_pin(InternalGPIOPin *pin) { this->interrupt_pin_ = pin; } protected: + static void IRAM_ATTR gpio_intr(PCA9554Component *arg); + bool read_inputs_(); bool write_register_(uint8_t reg, uint16_t value); @@ -48,6 +50,7 @@ class PCA9554Component : public Component, uint16_t input_mask_{0x00}; /// Storage for last I2C error seen esphome::i2c::ErrorCode last_error_; + InternalGPIOPin *interrupt_pin_{nullptr}; }; /// Helper class to expose a PCA9554 pin as an internal input GPIO pin. diff --git a/esphome/components/pcf8574/__init__.py b/esphome/components/pcf8574/__init__.py index f387d0a610..902efd2279 100644 --- a/esphome/components/pcf8574/__init__.py +++ b/esphome/components/pcf8574/__init__.py @@ -5,6 +5,7 @@ import esphome.config_validation as cv from esphome.const import ( CONF_ID, CONF_INPUT, + CONF_INTERRUPT_PIN, CONF_INVERTED, CONF_MODE, CONF_NUMBER, @@ -27,6 +28,7 @@ CONFIG_SCHEMA = ( { cv.Required(CONF_ID): cv.declare_id(PCF8574Component), cv.Optional(CONF_PCF8575, default=False): cv.boolean, + cv.Optional(CONF_INTERRUPT_PIN): pins.internal_gpio_input_pin_schema, } ) .extend(cv.COMPONENT_SCHEMA) @@ -39,6 +41,8 @@ async def to_code(config): await cg.register_component(var, config) await i2c.register_i2c_device(var, config) cg.add(var.set_pcf8575(config[CONF_PCF8575])) + if interrupt_pin := config.get(CONF_INTERRUPT_PIN): + cg.add(var.set_interrupt_pin(await cg.gpio_pin_expression(interrupt_pin))) def validate_mode(value): diff --git a/esphome/components/pcf8574/pcf8574.cpp b/esphome/components/pcf8574/pcf8574.cpp index d3ec31436d..27c5d5a2ab 100644 --- a/esphome/components/pcf8574/pcf8574.cpp +++ b/esphome/components/pcf8574/pcf8574.cpp @@ -15,16 +15,29 @@ void PCF8574Component::setup() { this->write_gpio_(); this->read_gpio_(); + + if (this->interrupt_pin_ != nullptr) { + this->interrupt_pin_->setup(); + this->interrupt_pin_->attach_interrupt(&PCF8574Component::gpio_intr, this, gpio::INTERRUPT_FALLING_EDGE); + // With interrupt pin, only run loop when interrupt fires + this->disable_loop(); + } } +void IRAM_ATTR PCF8574Component::gpio_intr(PCF8574Component *arg) { arg->enable_loop_soon_any_context(); } void PCF8574Component::loop() { - // Invalidate the cache at the start of each loop + // Invalidate the cache so the next digital_read() triggers a fresh I2C read this->reset_pin_cache_(); + if (this->interrupt_pin_ != nullptr) { + // Interrupt-driven: disable loop until next interrupt fires + this->disable_loop(); + } } void PCF8574Component::dump_config() { ESP_LOGCONFIG(TAG, "PCF8574:\n" " Is PCF8575: %s", YESNO(this->pcf8575_)); + LOG_PIN(" Interrupt Pin: ", this->interrupt_pin_); LOG_I2C_DEVICE(this) if (this->is_failed()) { ESP_LOGE(TAG, ESP_LOG_MSG_COMM_FAIL); diff --git a/esphome/components/pcf8574/pcf8574.h b/esphome/components/pcf8574/pcf8574.h index b039173789..cae2e930b7 100644 --- a/esphome/components/pcf8574/pcf8574.h +++ b/esphome/components/pcf8574/pcf8574.h @@ -17,10 +17,10 @@ class PCF8574Component : public Component, PCF8574Component() = default; void set_pcf8575(bool pcf8575) { pcf8575_ = pcf8575; } + void set_interrupt_pin(InternalGPIOPin *pin) { this->interrupt_pin_ = pin; } /// Check i2c availability and setup masks void setup() override; - /// Invalidate cache at start of each loop void loop() override; /// Helper function to set the pin mode of a pin. void pin_mode(uint8_t pin, gpio::Flags flags); @@ -30,6 +30,8 @@ class PCF8574Component : public Component, void dump_config() override; protected: + static void IRAM_ATTR gpio_intr(PCF8574Component *arg); + bool digital_read_hw(uint8_t pin) override; bool digital_read_cache(uint8_t pin) override; void digital_write_hw(uint8_t pin, bool value) override; @@ -44,6 +46,7 @@ class PCF8574Component : public Component, /// The state read in read_gpio_ - 1 means HIGH, 0 means LOW uint16_t input_mask_{0x00}; bool pcf8575_; ///< TRUE->16-channel PCF8575, FALSE->8-channel PCF8574 + InternalGPIOPin *interrupt_pin_{nullptr}; }; /// Helper class to expose a PCF8574 pin as an internal input GPIO pin.