From fffa34204836a9efabe2841024147d75959d9956 Mon Sep 17 00:00:00 2001
From: Jesse Hills <jesse@springload.co.nz>
Date: Mon, 27 May 2019 07:16:57 +1200
Subject: [PATCH] Add CT Clamp component

---
 esphome/components/ct_clamp/__init__.py       |  0
 .../components/ct_clamp/ct_clamp_sensor.cpp   | 64 +++++++++++++++++++
 esphome/components/ct_clamp/ct_clamp_sensor.h | 48 ++++++++++++++
 esphome/components/ct_clamp/sensor.py         | 31 +++++++++
 4 files changed, 143 insertions(+)
 create mode 100644 esphome/components/ct_clamp/__init__.py
 create mode 100644 esphome/components/ct_clamp/ct_clamp_sensor.cpp
 create mode 100644 esphome/components/ct_clamp/ct_clamp_sensor.h
 create mode 100644 esphome/components/ct_clamp/sensor.py

diff --git a/esphome/components/ct_clamp/__init__.py b/esphome/components/ct_clamp/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/esphome/components/ct_clamp/ct_clamp_sensor.cpp b/esphome/components/ct_clamp/ct_clamp_sensor.cpp
new file mode 100644
index 0000000000..c4a856f214
--- /dev/null
+++ b/esphome/components/ct_clamp/ct_clamp_sensor.cpp
@@ -0,0 +1,64 @@
+#include "esphome/components/ct_clamp/ct_clamp_sensor.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace ct_clamp {
+
+static const char *TAG = "ct_clamp";
+
+void CTClampSensor::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up CT Clamp '%s'...", this->get_name().c_str());
+  GPIOPin(this->pin_, INPUT).setup();
+
+  offsetI = ADC_COUNTS>>1;
+
+}
+
+void CTClampSensor::dump_config() {
+  LOG_SENSOR("", "CT Clamp Sensor", this);
+  ESP_LOGCONFIG(TAG, "  Pin: %u", this->pin_);
+  ESP_LOGCONFIG(TAG, "  Calibration: %u", this->calibration_);
+  ESP_LOGCONFIG(TAG, "  Sample Size: %u", this->sample_size_);
+  ESP_LOGCONFIG(TAG, "  Supply Voltage: %0.2fV", this->supply_voltage_);
+  LOG_UPDATE_INTERVAL(this);
+}
+
+float CTClampSensor::get_setup_priority() const { return setup_priority::DATA; }
+
+void CTClampSensor::update() {
+
+  for (unsigned int n = 0; n < this->sample_size_; n++)
+  {
+    sampleI = analogRead(this->pin_);
+
+    // Digital low pass filter extracts the 1.65 V dc offset,
+    //  then subtract this - signal is now centered on 0 counts.
+    offsetI = (offsetI + (sampleI-offsetI)/(ADC_COUNTS));
+    filteredI = sampleI - offsetI;
+
+    // Root-mean-square method current
+    // 1) square current values
+    sqI = filteredI * filteredI;
+    // 2) sum
+    sumI += sqI;
+  }
+
+  double I_RATIO = this->calibration_ * ((supply_voltage_) / (ADC_COUNTS));
+  Irms = I_RATIO * sqrt(sumI / this->sample_size_);
+
+  //Reset accumulators
+  sumI = 0;
+
+  ESP_LOGD(TAG, "'%s'", this->get_name().c_str(), Irms);
+  ESP_LOGD(TAG, "   Amps=%.2fA", Irms);
+  ESP_LOGD(TAG, "   Watts=%.0fW", Irms * 230.0);
+
+  this->publish_state(Irms);
+}
+
+#ifdef ARDUINO_ARCH_ESP8266
+std::string CTClampSensor::unique_id() { return get_mac_address() + "-ct_clamp"; }
+#endif
+
+}  // namespace ct_clamp
+}  // namespace esphome
diff --git a/esphome/components/ct_clamp/ct_clamp_sensor.h b/esphome/components/ct_clamp/ct_clamp_sensor.h
new file mode 100644
index 0000000000..a3d444f60c
--- /dev/null
+++ b/esphome/components/ct_clamp/ct_clamp_sensor.h
@@ -0,0 +1,48 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/core/esphal.h"
+#include "esphome/components/sensor/sensor.h"
+
+namespace esphome {
+namespace ct_clamp {
+
+class CTClampSensor : public sensor::Sensor, public PollingComponent {
+ public:
+  /// Update CT Clamp sensor values.
+  void update() override;
+  /// Setup CT Sensor
+  void setup() override;
+  void dump_config() override;
+  /// `HARDWARE_LATE` setup priority.
+  float get_setup_priority() const override;
+
+  void set_pin(uint8_t pin) { this->pin_ = pin; }
+  void set_calibration(uint32_t calibration) { this->calibration_ = calibration; }
+  void set_sample_size(uint32_t sample_size) { this->sample_size_ = sample_size; }
+  void set_supply_voltage(double supply_voltage) { this->supply_voltage_ = supply_voltage; }
+
+#ifdef ARDUINO_ARCH_ESP8266
+  std::string unique_id() override;
+#endif
+
+ protected:
+  uint8_t pin_;
+  uint32_t calibration_;
+  uint32_t sample_size_;
+  double supply_voltage_;
+
+  int sampleI;
+  double Irms,filteredI,offsetI,sumI,sqI;
+
+#ifdef ARDUINO_ARCH_ESP32
+#define ADC_BITS    12
+#endif
+#ifdef ARDUINO_ARCH_ESP8266
+#define ADC_BITS    10
+#endif
+#define ADC_COUNTS  (1<<ADC_BITS)
+};
+
+} // namespace ct_clamp
+} // namespace esphome
diff --git a/esphome/components/ct_clamp/sensor.py b/esphome/components/ct_clamp/sensor.py
new file mode 100644
index 0000000000..e2c9400c98
--- /dev/null
+++ b/esphome/components/ct_clamp/sensor.py
@@ -0,0 +1,31 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome import pins
+from esphome.components import sensor
+from esphome.const import CONF_ID, CONF_PIN, ICON_FLASH, UNIT_AMPERE
+
+CONF_CALIBRATION = 'calibration'
+CONF_SAMPLE_SIZE = 'sample_size'
+CONF_SUPPLY_VOLTAGE = 'supply_voltage'
+
+ct_clamp_ns = cg.esphome_ns.namespace('ct_clamp')
+CTClampSensor = ct_clamp_ns.class_('CTClampSensor', sensor.Sensor, cg.PollingComponent)
+
+CONFIG_SCHEMA = sensor.sensor_schema(UNIT_AMPERE, ICON_FLASH, 2).extend({
+    cv.GenerateID(): cv.declare_id(CTClampSensor),
+    cv.Required(CONF_PIN): pins.analog_pin,
+    cv.Required(CONF_CALIBRATION): cv.positive_int,
+    cv.Optional(CONF_SAMPLE_SIZE, default=1480): cv.positive_int,
+    cv.Optional(CONF_SUPPLY_VOLTAGE, default='1V'): cv.voltage,
+}).extend(cv.polling_component_schema('60s'))
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+    yield sensor.register_sensor(var, config)
+
+    cg.add(var.set_pin(config[CONF_PIN]))
+    cg.add(var.set_calibration(config[CONF_CALIBRATION]))
+    cg.add(var.set_sample_size(config[CONF_SAMPLE_SIZE]))
+    cg.add(var.set_supply_voltage(config[CONF_SUPPLY_VOLTAGE]))