bl0940.h

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#pragma once

#include "esphome/core/component.h"
#include "esphome/components/uart/uart.h"
#include "esphome/components/sensor/sensor.h"

namespace esphome {
namespace bl0940 {

static const float BL0940_PREF = 1430;
static const float BL0940_UREF = 33000;
static const float BL0940_IREF = 275000;  // 2750 from tasmota. Seems to generate values 100 times too high

// Measured to 297J  per click according to power consumption of 5 minutes
// Converted to kWh (3.6MJ per kwH). Used to be 256 * 1638.4
static const float BL0940_EREF = 3.6e6 / 297;

struct ube24_t {  // NOLINT(readability-identifier-naming,altera-struct-pack-align)
  uint8_t l;
  uint8_t m;
  uint8_t h;
} __attribute__((packed));

struct ube16_t {  // NOLINT(readability-identifier-naming,altera-struct-pack-align)
  uint8_t l;
  uint8_t h;
} __attribute__((packed));

struct sbe24_t {  // NOLINT(readability-identifier-naming,altera-struct-pack-align)
  uint8_t l;
  uint8_t m;
  int8_t h;
} __attribute__((packed));

// Caveat: All these values are big endian (low - middle - high)

union DataPacket {  // NOLINT(altera-struct-pack-align)
  uint8_t raw[35];
  struct {
    uint8_t frame_header;  // value of 0x58 according to docs. 0x55 according to Tasmota real world tests. Reality wins.
    ube24_t i_fast_rms;    // 0x00
    ube24_t i_rms;         // 0x04
    ube24_t RESERVED0;     // reserved
    ube24_t v_rms;         // 0x06
    ube24_t RESERVED1;     // reserved
    sbe24_t watt;          // 0x08
    ube24_t RESERVED2;     // reserved
    ube24_t cf_cnt;        // 0x0A
    ube24_t RESERVED3;     // reserved
    ube16_t tps1;          // 0x0c
    uint8_t RESERVED4;     // value of 0x00
    ube16_t tps2;          // 0x0c
    uint8_t RESERVED5;     // value of 0x00
    uint8_t checksum;      // checksum
  };
} __attribute__((packed));

class BL0940 : public PollingComponent, public uart::UARTDevice {
 public:
  void set_voltage_sensor(sensor::Sensor *voltage_sensor) { voltage_sensor_ = voltage_sensor; }
  void set_current_sensor(sensor::Sensor *current_sensor) { current_sensor_ = current_sensor; }
  void set_power_sensor(sensor::Sensor *power_sensor) { power_sensor_ = power_sensor; }
  void set_energy_sensor(sensor::Sensor *energy_sensor) { energy_sensor_ = energy_sensor; }
  void set_internal_temperature_sensor(sensor::Sensor *internal_temperature_sensor) {
    internal_temperature_sensor_ = internal_temperature_sensor;
  }
  void set_external_temperature_sensor(sensor::Sensor *external_temperature_sensor) {
    external_temperature_sensor_ = external_temperature_sensor;
  }

  void loop() override;

  void update() override;
  void setup() override;
  void dump_config() override;

 protected:
  sensor::Sensor *voltage_sensor_{nullptr};
  sensor::Sensor *current_sensor_{nullptr};
  // NB This may be negative as the circuits is seemingly able to measure
  // power in both directions
  sensor::Sensor *power_sensor_{nullptr};
  sensor::Sensor *energy_sensor_{nullptr};
  sensor::Sensor *internal_temperature_sensor_{nullptr};
  sensor::Sensor *external_temperature_sensor_{nullptr};

  // Max difference between two measurements of the temperature. Used to avoid noise.
  float max_temperature_diff_{0};
  // Divide by this to turn into Watt
  float power_reference_ = BL0940_PREF;
  // Divide by this to turn into Volt
  float voltage_reference_ = BL0940_UREF;
  // Divide by this to turn into Ampere
  float current_reference_ = BL0940_IREF;
  // Divide by this to turn into kWh
  float energy_reference_ = BL0940_EREF;

  float update_temp_(sensor::Sensor *sensor, ube16_t packed_temperature) const;

  static uint32_t to_uint32_t(ube24_t input);

  static int32_t to_int32_t(sbe24_t input);

  static bool validate_checksum(const DataPacket *data);

  void received_package_(const DataPacket *data) const;
};
}  // namespace bl0940
}  // namespace esphome