[ultrasonic] Fix ISR edge detection with debounce and trigger filtering (#15014)

This commit is contained in:
Jonathan Swoboda
2026-03-22 16:19:46 -04:00
committed by Jesse Hills
parent de3292c828
commit bbfe324dd6
2 changed files with 14 additions and 18 deletions
@@ -6,11 +6,17 @@ namespace esphome::ultrasonic {
static const char *const TAG = "ultrasonic.sensor";
static constexpr uint32_t DEBOUNCE_US = 50; // Ignore edges within 50us of each other (noise filtering)
static constexpr uint32_t START_DELAY_US = 100; // Ignore edges within 100us of trigger (filters bleed-through)
static constexpr uint32_t START_TIMEOUT_US = 40000; // Maximum time to wait for echo pulse to start
void IRAM_ATTR UltrasonicSensorStore::gpio_intr(UltrasonicSensorStore *arg) {
uint32_t now = micros();
if (arg->echo_pin_isr.digital_read()) {
// Ignore edges after measurement complete or too soon after trigger pulse
if (arg->echo_end || (now - arg->measurement_start_us) <= START_DELAY_US) {
return;
}
if (!arg->echo_start || (now - arg->echo_start_us) <= DEBOUNCE_US) {
arg->echo_start_us = now;
arg->echo_start = true;
} else {
@@ -21,15 +27,14 @@ void IRAM_ATTR UltrasonicSensorStore::gpio_intr(UltrasonicSensorStore *arg) {
void IRAM_ATTR UltrasonicSensorComponent::send_trigger_pulse_() {
InterruptLock lock;
this->store_.echo_start_us = 0;
this->store_.echo_end_us = 0;
this->store_.echo_start = false;
this->store_.echo_end = false;
this->store_.measurement_start_us = micros();
this->trigger_pin_isr_.digital_write(true);
delayMicroseconds(this->pulse_time_us_);
this->trigger_pin_isr_.digital_write(false);
this->measurement_pending_ = true;
this->measurement_start_us_ = micros();
this->measurement_start_us_ = this->store_.measurement_start_us;
}
void UltrasonicSensorComponent::setup() {
@@ -37,7 +42,6 @@ void UltrasonicSensorComponent::setup() {
this->trigger_pin_->digital_write(false);
this->trigger_pin_isr_ = this->trigger_pin_->to_isr();
this->echo_pin_->setup();
this->store_.echo_pin_isr = this->echo_pin_->to_isr();
this->echo_pin_->attach_interrupt(UltrasonicSensorStore::gpio_intr, &this->store_, gpio::INTERRUPT_ANY_EDGE);
}
@@ -77,17 +81,10 @@ void UltrasonicSensorComponent::loop() {
}
if (this->store_.echo_end) {
float result;
if (this->store_.echo_start) {
uint32_t pulse_duration = this->store_.echo_end_us - this->store_.echo_start_us;
ESP_LOGV(TAG, "pulse start took %" PRIu32 "us, echo took %" PRIu32 "us",
this->store_.echo_start_us - this->measurement_start_us_, pulse_duration);
result = UltrasonicSensorComponent::us_to_m(pulse_duration);
ESP_LOGD(TAG, "'%s' - Got distance: %.3f m", this->name_.c_str(), result);
} else {
ESP_LOGW(TAG, "'%s' - pulse end before pulse start, does the echo pin need to be inverted?", this->name_.c_str());
result = NAN;
}
uint32_t pulse_duration = this->store_.echo_end_us - this->store_.echo_start_us;
ESP_LOGV(TAG, "Echo took %" PRIu32 "us", pulse_duration);
float result = UltrasonicSensorComponent::us_to_m(pulse_duration);
ESP_LOGD(TAG, "'%s' - Got distance: %.3f m", this->name_.c_str(), result);
this->publish_state(result);
this->measurement_pending_ = false;
return;
@@ -11,8 +11,7 @@ namespace esphome::ultrasonic {
struct UltrasonicSensorStore {
static void gpio_intr(UltrasonicSensorStore *arg);
ISRInternalGPIOPin echo_pin_isr;
volatile uint32_t wait_start_us{0};
volatile uint32_t measurement_start_us{0};
volatile uint32_t echo_start_us{0};
volatile uint32_t echo_end_us{0};
volatile bool echo_start{false};