Implement pulse_meter as an improvement on pulse_counter and pulse_width for meters (#1434)

esphome/components/pulse_meter/pulse_meter_sensor.cpp

@@ -0,0 +1,87 @@
+#include "pulse_meter_sensor.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace pulse_meter {
+
+static const char *TAG = "pulse_meter";
+
+void PulseMeterSensor::setup() {
+  this->pin_->setup();
+  this->isr_pin_ = pin_->to_isr();
+  this->pin_->attach_interrupt(PulseMeterSensor::gpio_intr, this, CHANGE);
+
+  this->last_detected_edge_us_ = 0;
+  this->last_valid_edge_us_ = 0;
+}
+
+void PulseMeterSensor::loop() {
+  const uint32_t now = micros();
+
+  // If we've exceeded our timeout interval without receiving any pulses, assume 0 pulses/min until
+  // we get at least two valid pulses.
+  const uint32_t time_since_valid_edge_us = now - this->last_valid_edge_us_;
+  if ((this->last_valid_edge_us_ != 0) && (time_since_valid_edge_us > this->timeout_us_)) {
+    ESP_LOGD(TAG, "No pulse detected for %us, assuming 0 pulses/min", time_since_valid_edge_us / 1000000);
+    this->last_detected_edge_us_ = 0;
+    this->last_valid_edge_us_ = 0;
+    this->pulse_width_us_ = 0;
+  }
+
+  // We quantize our pulse widths to 1 ms to avoid unnecessary jitter
+  const uint32_t pulse_width_ms = this->pulse_width_us_ / 1000;
+  if (this->pulse_width_dedupe_.next(pulse_width_ms)) {
+    if (pulse_width_ms == 0) {
+      // Treat 0 pulse width as 0 pulses/min (normally because we've not detected any pulses for a while)
+      this->publish_state(0);
+    } else {
+      // Calculate pulses/min from the pulse width in ms
+      this->publish_state((60.0 * 1000.0) / pulse_width_ms);
+    }
+  }
+
+  if (this->total_sensor_ != nullptr) {
+    const uint32_t total = this->total_pulses_;
+    if (this->total_dedupe_.next(total)) {
+      this->total_sensor_->publish_state(total);
+    }
+  }
+}
+
+void PulseMeterSensor::dump_config() {
+  LOG_SENSOR("", "Pulse Meter", this);
+  LOG_PIN("  Pin: ", this->pin_);
+  ESP_LOGCONFIG(TAG, "  Filtering pulses shorter than %u µs", this->filter_us_);
+  ESP_LOGCONFIG(TAG, "  Assuming 0 pulses/min after not receiving a pulse for %us", this->timeout_us_ / 1000000);
+}
+
+void ICACHE_RAM_ATTR PulseMeterSensor::gpio_intr(PulseMeterSensor *sensor) {
+  // This is an interrupt handler - we can't call any virtual method from this method
+
+  // Get the current time before we do anything else so the measurements are consistent
+  const uint32_t now = micros();
+
+  // We only look at rising edges
+  if (!sensor->isr_pin_->digital_read()) {
+    return;
+  }
+
+  // Ignore the first detected pulse (we need at least two pulses to measure the width)
+  if (sensor->last_detected_edge_us_ != 0) {
+    // Check to see if we should filter this edge out
+    if ((now - sensor->last_detected_edge_us_) >= sensor->filter_us_) {
+      // Don't measure the first valid pulse (we need at least two pulses to measure the width)
+      if (sensor->last_valid_edge_us_ != 0) {
+        sensor->pulse_width_us_ = (now - sensor->last_valid_edge_us_);
+      }
+
+      sensor->total_pulses_++;
+      sensor->last_valid_edge_us_ = now;
+    }
+  }
+
+  sensor->last_detected_edge_us_ = now;
+}
+
+}  // namespace pulse_meter
+}  // namespace esphome