diff --git a/esphome/components/pca9554/pca9554.cpp b/esphome/components/pca9554/pca9554.cpp index 39093fcf54..74c64dffaa 100644 --- a/esphome/components/pca9554/pca9554.cpp +++ b/esphome/components/pca9554/pca9554.cpp @@ -26,7 +26,7 @@ void PCA9554Component::setup() { this->config_mask_ = 0; // Invert mask as the part sees a 1 as an input this->write_register_(CONFIG_REG, ~this->config_mask_); - // All ouputs low + // All outputs low this->output_mask_ = 0; this->write_register_(OUTPUT_REG, this->output_mask_); // Read the inputs @@ -34,6 +34,14 @@ void PCA9554Component::setup() { ESP_LOGD(TAG, "Initialization complete. Warning: %d, Error: %d", this->status_has_warning(), this->status_has_error()); } + +void PCA9554Component::loop() { + // The read_inputs_() method will cache the input values from the chip. + this->read_inputs_(); + // Clear all the previously read flags. + this->was_previously_read_ = 0x00; +} + void PCA9554Component::dump_config() { ESP_LOGCONFIG(TAG, "PCA9554:"); LOG_I2C_DEVICE(this) @@ -43,7 +51,16 @@ void PCA9554Component::dump_config() { } bool PCA9554Component::digital_read(uint8_t pin) { - this->read_inputs_(); + // Note: We want to try and avoid doing any I2C bus read transactions here + // to conserve I2C bus bandwidth. So what we do is check to see if we + // have seen a read during the time esphome is running this loop. If we have, + // we do an I2C bus transaction to get the latest value. If we haven't + // we return a cached value which was read at the time loop() was called. + if (this->was_previously_read_ & (1 << pin)) + this->read_inputs_(); // Force a read of a new value + // Indicate we saw a read request for this pin in case a + // read happens later in the same loop. + this->was_previously_read_ |= (1 << pin); return this->input_mask_ & (1 << pin); } @@ -98,6 +115,10 @@ bool PCA9554Component::write_register_(uint8_t reg, uint8_t value) { float PCA9554Component::get_setup_priority() const { return setup_priority::IO; } +// Run our loop() method very early in the loop, so that we cache read values before +// before other components call our digital_read() method. +float PCA9554Component::get_loop_priority() const { return 9.0f; } // Just after WIFI + void PCA9554GPIOPin::setup() { pin_mode(flags_); } void PCA9554GPIOPin::pin_mode(gpio::Flags flags) { this->parent_->pin_mode(this->pin_, flags); } bool PCA9554GPIOPin::digital_read() { return this->parent_->digital_read(this->pin_) != this->inverted_; } diff --git a/esphome/components/pca9554/pca9554.h b/esphome/components/pca9554/pca9554.h index d1bfc36bec..c2aa5c30ed 100644 --- a/esphome/components/pca9554/pca9554.h +++ b/esphome/components/pca9554/pca9554.h @@ -13,6 +13,8 @@ class PCA9554Component : public Component, public i2c::I2CDevice { /// Check i2c availability and setup masks void setup() override; + /// Poll for input changes periodically + void loop() override; /// Helper function to read the value of a pin. bool digital_read(uint8_t pin); /// Helper function to write the value of a pin. @@ -22,6 +24,8 @@ class PCA9554Component : public Component, public i2c::I2CDevice { float get_setup_priority() const override; + float get_loop_priority() const override; + void dump_config() override; protected: @@ -35,6 +39,8 @@ class PCA9554Component : public Component, public i2c::I2CDevice { uint8_t output_mask_{0x00}; /// The state of the actual input pin states - 1 means HIGH, 0 means LOW uint8_t input_mask_{0x00}; + /// Flags to check if read previously during this loop + uint8_t was_previously_read_ = {0x00}; /// Storage for last I2C error seen esphome::i2c::ErrorCode last_error_; };