CT Clamp ADS1115 Improvements (#647)

Fixes https://github.com/esphome/issues/issues/457

esphome/components/ads1115/__init__.py

@@ -10,8 +10,10 @@ MULTI_CONF = True
 ads1115_ns = cg.esphome_ns.namespace('ads1115')
 ADS1115Component = ads1115_ns.class_('ADS1115Component', cg.Component, i2c.I2CDevice)
 
+CONF_CONTINUOUS_MODE = 'continuous_mode'
 CONFIG_SCHEMA = cv.Schema({
     cv.GenerateID(): cv.declare_id(ADS1115Component),
+    cv.Optional(CONF_CONTINUOUS_MODE, default=False): cv.boolean,
 }).extend(cv.COMPONENT_SCHEMA).extend(i2c.i2c_device_schema(None))
 
 
@@ -19,3 +21,5 @@ def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     yield cg.register_component(var, config)
     yield i2c.register_i2c_device(var, config)
+
+    cg.add(var.set_continuous_mode(config[CONF_CONTINUOUS_MODE]))

esphome/components/ads1115/ads1115.cpp

@@ -29,9 +29,15 @@ void ADS1115Component::setup() {
   //        0bxxxx000xxxxxxxxx
   config |= ADS1115_GAIN_6P144 << 9;
 
-  // Set singleshot mode
-  //        0bxxxxxxx1xxxxxxxx
-  config |= 0b0000000100000000;
+  if (this->continuous_mode_) {
+    // Set continuous mode
+    //        0bxxxxxxx0xxxxxxxx
+    config |= 0b0000000000000000;
+  } else {
+    // Set singleshot mode
+    //        0bxxxxxxx1xxxxxxxx
+    config |= 0b0000000100000000;
+  }
 
   // Set data rate - 860 samples per second (we're in singleshot mode)
   //        0bxxxxxxxx100xxxxx
@@ -57,6 +63,8 @@ void ADS1115Component::setup() {
     this->mark_failed();
     return;
   }
+  this->prev_config_ = config;
+
   for (auto *sensor : this->sensors_) {
     this->set_interval(sensor->get_name(), sensor->update_interval(),
                        [this, sensor] { this->request_measurement(sensor); });
@@ -75,13 +83,8 @@ void ADS1115Component::dump_config() {
     ESP_LOGCONFIG(TAG, "    Gain: %u", sensor->get_gain());
   }
 }
-float ADS1115Component::get_setup_priority() const { return setup_priority::DATA; }
 float ADS1115Component::request_measurement(ADS1115Sensor *sensor) {
-  uint16_t config;
-  if (!this->read_byte_16(ADS1115_REGISTER_CONFIG, &config)) {
-    this->status_set_warning();
-    return NAN;
-  }
+  uint16_t config = this->prev_config_;
   // Multiplexer
   //        0bxBBBxxxxxxxxxxxx
   config &= 0b1000111111111111;
@@ -91,25 +94,31 @@ float ADS1115Component::request_measurement(ADS1115Sensor *sensor) {
   //        0bxxxxBBBxxxxxxxxx
   config &= 0b1111000111111111;
   config |= (sensor->get_gain() & 0b111) << 9;
-  // Start conversion
-  config |= 0b1000000000000000;
 
-  if (!this->write_byte_16(ADS1115_REGISTER_CONFIG, config)) {
-    this->status_set_warning();
-    return NAN;
+  if (!this->continuous_mode_) {
+    // Start conversion
+    config |= 0b1000000000000000;
   }
 
-  // about 1.6 ms with 860 samples per second
-  delay(2);
-
-  uint32_t start = millis();
-  while (this->read_byte_16(ADS1115_REGISTER_CONFIG, &config) && (config >> 15) == 0) {
-    if (millis() - start > 100) {
-      ESP_LOGW(TAG, "Reading ADS1115 timed out");
+  if (!this->continuous_mode_ || this->prev_config_ != config) {
+    if (!this->write_byte_16(ADS1115_REGISTER_CONFIG, config)) {
       this->status_set_warning();
       return NAN;
     }
-    yield();
+    this->prev_config_ = config;
+
+    // about 1.6 ms with 860 samples per second
+    delay(2);
+
+    uint32_t start = millis();
+    while (this->read_byte_16(ADS1115_REGISTER_CONFIG, &config) && (config >> 15) == 0) {
+      if (millis() - start > 100) {
+        ESP_LOGW(TAG, "Reading ADS1115 timed out");
+        this->status_set_warning();
+        return NAN;
+      }
+      yield();
+    }
   }
 
   uint16_t raw_conversion;
@@ -147,10 +156,6 @@ float ADS1115Component::request_measurement(ADS1115Sensor *sensor) {
   return millivolts / 1e3f;
 }
 
-uint8_t ADS1115Sensor::get_multiplexer() const { return this->multiplexer_; }
-void ADS1115Sensor::set_multiplexer(ADS1115Multiplexer multiplexer) { this->multiplexer_ = multiplexer; }
-uint8_t ADS1115Sensor::get_gain() const { return this->gain_; }
-void ADS1115Sensor::set_gain(ADS1115Gain gain) { this->gain_ = gain; }
 float ADS1115Sensor::sample() { return this->parent_->request_measurement(this); }
 void ADS1115Sensor::update() {
   float v = this->parent_->request_measurement(this);

esphome/components/ads1115/ads1115.h

@@ -37,13 +37,16 @@ class ADS1115Component : public Component, public i2c::I2CDevice {
   void setup() override;
   void dump_config() override;
   /// HARDWARE_LATE setup priority
-  float get_setup_priority() const override;
+  float get_setup_priority() const override { return setup_priority::DATA; }
+  void set_continuous_mode(bool continuous_mode) { continuous_mode_ = continuous_mode; }
 
   /// Helper method to request a measurement from a sensor.
   float request_measurement(ADS1115Sensor *sensor);
 
  protected:
   std::vector<ADS1115Sensor *> sensors_;
+  uint16_t prev_config_{0};
+  bool continuous_mode_;
 };
 
 /// Internal holder class that is in instance of Sensor so that the hub can create individual sensors.
@@ -51,12 +54,12 @@ class ADS1115Sensor : public sensor::Sensor, public PollingComponent, public vol
  public:
   ADS1115Sensor(ADS1115Component *parent) : parent_(parent) {}
   void update() override;
-  void set_multiplexer(ADS1115Multiplexer multiplexer);
-  void set_gain(ADS1115Gain gain);
+  void set_multiplexer(ADS1115Multiplexer multiplexer) { multiplexer_ = multiplexer; }
+  void set_gain(ADS1115Gain gain) { gain_ = gain; }
 
   float sample() override;
-  uint8_t get_multiplexer() const;
-  uint8_t get_gain() const;
+  uint8_t get_multiplexer() const { return multiplexer_; }
+  uint8_t get_gain() const { return gain_; }
 
  protected:
   ADS1115Component *parent_;

esphome/components/ct_clamp/ct_clamp_sensor.cpp

@@ -8,6 +8,18 @@ namespace ct_clamp {
 
 static const char *TAG = "ct_clamp";
 
+void CTClampSensor::setup() {
+  this->is_calibrating_offset_ = true;
+  this->high_freq_.start();
+  this->set_timeout("calibrate_offset", this->sample_duration_, [this]() {
+    this->high_freq_.stop();
+    this->is_calibrating_offset_ = false;
+    if (this->num_samples_ != 0) {
+      this->offset_ = this->sample_sum_ / this->num_samples_;
+    }
+  });
+}
+
 void CTClampSensor::dump_config() {
   LOG_SENSOR("", "CT Clamp Sensor", this);
   ESP_LOGCONFIG(TAG, "  Sample Duration: %.2fs", this->sample_duration_ / 1e3f);
@@ -15,6 +27,9 @@ void CTClampSensor::dump_config() {
 }
 
 void CTClampSensor::update() {
+  if (this->is_calibrating_offset_)
+    return;
+
   // Update only starts the sampling phase, in loop() the actual sampling is happening.
 
   // Request a high loop() execution interval during sampling phase.
@@ -44,12 +59,18 @@ void CTClampSensor::update() {
 }
 
 void CTClampSensor::loop() {
-  if (!this->is_sampling_)
+  if (!this->is_sampling_ || !this->is_calibrating_offset_)
     return;
 
   // Perform a single sample
   float value = this->source_->sample();
 
+  if (this->is_calibrating_offset_) {
+    this->sample_sum_ += value;
+    this->num_samples_++;
+    return;
+  }
+
   // Adjust DC offset via low pass filter (exponential moving average)
   const float alpha = 0.001f;
   this->offset_ = this->offset_ * (1 - alpha) + value * alpha;

esphome/components/ct_clamp/ct_clamp_sensor.h

@@ -10,10 +10,14 @@ namespace ct_clamp {
 
 class CTClampSensor : public sensor::Sensor, public PollingComponent {
  public:
+  void setup() override;
   void update() override;
   void loop() override;
   void dump_config() override;
-  float get_setup_priority() const override { return setup_priority::DATA; }
+  float get_setup_priority() const override {
+    // After the base sensor has been initialized
+    return setup_priority::DATA - 1.0f;
+  }
 
   void set_sample_duration(uint32_t sample_duration) { sample_duration_ = sample_duration; }
   void set_source(voltage_sampler::VoltageSampler *source) { source_ = source; }
@@ -40,6 +44,8 @@ class CTClampSensor : public sensor::Sensor, public PollingComponent {
   float sample_sum_ = 0.0f;
   uint32_t num_samples_ = 0;
   bool is_sampling_ = false;
+  /// Calibrate offset value once at boot
+  bool is_calibrating_offset_ = false;
 };
 
 }  // namespace ct_clamp