opentherm.h

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/*
 * OpenTherm protocol implementation. Originally taken from https://github.com/jpraus/arduino-opentherm, but
 * heavily modified to comply with ESPHome coding standards and provide better logging.
 * Original code is licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International
 * Public License, which is compatible with GPLv3 license, which covers C++ part of ESPHome project.
 */
 
#pragma once
 
#include <string>
#include "esphome/core/hal.h"
#include "esphome/core/helpers.h"
#include "esphome/core/log.h"
 
#ifdef USE_ESP32
#include "driver/gptimer.h"
#endif
 
namespace esphome::opentherm {
 
template<class T> constexpr T read_bit(T value, uint8_t bit) { return (value >> bit) & 0x01; }
 
template<class T> constexpr T set_bit(T value, uint8_t bit) { return value |= (1UL << bit); }
 
template<class T> constexpr T clear_bit(T value, uint8_t bit) { return value &= ~(1UL << bit); }
 
template<class T> constexpr T write_bit(T value, uint8_t bit, uint8_t bit_value) {
  return bit_value ? set_bit(value, bit) : clear_bit(value, bit);
}
 
enum OperationMode {
  IDLE = 0,  // no operation
 
  LISTEN = 1,    // waiting for transmission to start
  READ = 2,      // reading 32-bit data frame
  RECEIVED = 3,  // data frame received with valid start and stop bit
 
  WRITE = 4,  // writing data to output
  SENT = 5,   // all data written to output
 
  ERROR_PROTOCOL = 8,  // protocol error, can happed only during READ
  ERROR_TIMEOUT = 9,   // timeout while waiting for response from device, only during LISTEN
  ERROR_TIMER = 10     // error operating the ESP32 timer
};
 
enum ProtocolErrorType {
  NO_ERROR = 0,            // No error
  NO_TRANSITION = 1,       // No transition in the middle of the bit
  INVALID_STOP_BIT = 2,    // Stop bit wasn't present when expected
  PARITY_ERROR = 3,        // Parity check didn't pass
  NO_CHANGE_TOO_LONG = 4,  // No level change for too much timer ticks
};
 
enum TimerErrorType {
  NO_TIMER_ERROR = 0,           // No error
  SET_ALARM_VALUE_ERROR = 1,    // No transition in the middle of the bit
  TIMER_START_ERROR = 2,        // Stop bit wasn't present when expected
  TIMER_PAUSE_ERROR = 3,        // Parity check didn't pass
  SET_COUNTER_VALUE_ERROR = 4,  // No level change for too much timer ticks
};
 
enum MessageType {
  READ_DATA = 0,
  READ_ACK = 4,
  WRITE_DATA = 1,
  WRITE_ACK = 5,
  INVALID_DATA = 2,
  DATA_INVALID = 6,
  UNKNOWN_DATAID = 7
};
 
enum MessageId {
  STATUS = 0,
  CH_SETPOINT = 1,
  CONTROLLER_CONFIG = 2,
  DEVICE_CONFIG = 3,
  COMMAND_CODE = 4,
  FAULT_FLAGS = 5,
  REMOTE = 6,
  COOLING_CONTROL = 7,
  CH2_SETPOINT = 8,
  CH_SETPOINT_OVERRIDE = 9,
  TSP_COUNT = 10,
  TSP_COMMAND = 11,
  FHB_SIZE = 12,
  FHB_COMMAND = 13,
  MAX_MODULATION_LEVEL = 14,
  MAX_BOILER_CAPACITY = 15,  // u8_hb - u8_lb gives min modulation level
  ROOM_SETPOINT = 16,
  MODULATION_LEVEL = 17,
  CH_WATER_PRESSURE = 18,
  DHW_FLOW_RATE = 19,
  DAY_TIME = 20,
  DATE = 21,
  YEAR = 22,
  ROOM_SETPOINT_CH2 = 23,
  ROOM_TEMP = 24,
  FEED_TEMP = 25,
  DHW_TEMP = 26,
  OUTSIDE_TEMP = 27,
  RETURN_WATER_TEMP = 28,
  SOLAR_STORE_TEMP = 29,
  SOLAR_COLLECT_TEMP = 30,
  FEED_TEMP_CH2 = 31,
  DHW2_TEMP = 32,
  EXHAUST_TEMP = 33,
  FAN_SPEED = 35,
  FLAME_CURRENT = 36,
  ROOM_TEMP_CH2 = 37,
  REL_HUMIDITY = 38,
  DHW_BOUNDS = 48,
  CH_BOUNDS = 49,
  OTC_CURVE_BOUNDS = 50,
  DHW_SETPOINT = 56,
  MAX_CH_SETPOINT = 57,
  OTC_CURVE_RATIO = 58,
 
  // HVAC Specific Message IDs
  HVAC_STATUS = 70,
  REL_VENT_SETPOINT = 71,
  DEVICE_VENT = 74,
  HVAC_VER_ID = 75,
  REL_VENTILATION = 77,
  REL_HUMID_EXHAUST = 78,
  EXHAUST_CO2 = 79,
  SUPPLY_INLET_TEMP = 80,
  SUPPLY_OUTLET_TEMP = 81,
  EXHAUST_INLET_TEMP = 82,
  EXHAUST_OUTLET_TEMP = 83,
  EXHAUST_FAN_SPEED = 84,
  SUPPLY_FAN_SPEED = 85,
  REMOTE_VENTILATION_PARAM = 86,
  NOM_REL_VENTILATION = 87,
  HVAC_NUM_TSP = 88,
  HVAC_IDX_TSP = 89,
  HVAC_FHB_SIZE = 90,
  HVAC_FHB_IDX = 91,
 
  RF_SIGNAL = 98,
  DHW_MODE = 99,
  OVERRIDE_FUNC = 100,
 
  // Solar Specific Message IDs
  SOLAR_MODE_FLAGS = 101,  // hb0-2 Controller storage mode
                           // lb0   Device fault
                           // lb1-3 Device mode status
                           // lb4-5 Device status
  SOLAR_ASF = 102,
  SOLAR_VERSION_ID = 103,
  SOLAR_PRODUCT_ID = 104,
  SOLAR_NUM_TSP = 105,
  SOLAR_IDX_TSP = 106,
  SOLAR_FHB_SIZE = 107,
  SOLAR_FHB_IDX = 108,
  SOLAR_STARTS = 109,
  SOLAR_HOURS = 110,
  SOLAR_ENERGY = 111,
  SOLAR_TOTAL_ENERGY = 112,
 
  FAILED_BURNER_STARTS = 113,
  BURNER_FLAME_LOW = 114,
  OEM_DIAGNOSTIC = 115,
  BURNER_STARTS = 116,
  CH_PUMP_STARTS = 117,
  DHW_PUMP_STARTS = 118,
  DHW_BURNER_STARTS = 119,
  BURNER_HOURS = 120,
  CH_PUMP_HOURS = 121,
  DHW_PUMP_HOURS = 122,
  DHW_BURNER_HOURS = 123,
  OT_VERSION_CONTROLLER = 124,
  OT_VERSION_DEVICE = 125,
  VERSION_CONTROLLER = 126,
  VERSION_DEVICE = 127
};
 
enum BitPositions { STOP_BIT = 33 };
 
struct OpenthermData {
  uint8_t type;
  uint8_t id;
  uint8_t valueHB;
  uint8_t valueLB;
 
  OpenthermData() : type(0), id(0), valueHB(0), valueLB(0) {}
 
  float f88();
 
  void f88(float value);
 
  uint16_t u16();
 
  void u16(uint16_t value);
 
  int16_t s16();
 
  void s16(int16_t value);
};
 
struct OpenThermError {
  ProtocolErrorType error_type;
  uint32_t capture;
  uint8_t clock;
  uint32_t data;
  uint8_t bit_pos;
};
 
class OpenTherm {
 public:
  OpenTherm(InternalGPIOPin *in_pin, InternalGPIOPin *out_pin, int32_t device_timeout = 800);
 
  bool initialize();
 
  void listen();
 
  bool has_message() { return mode_ == OperationMode::RECEIVED; }
 
  bool get_message(OpenthermData &data);
 
  void send(OpenthermData &data);
 
  void stop();
 
  bool get_protocol_error(OpenThermError &error);
 
  bool is_sent() { return mode_ == OperationMode::SENT; }
 
  bool is_idle() { return mode_ == OperationMode::IDLE; }
 
  bool is_error() {
    return mode_ == OperationMode::ERROR_TIMEOUT || mode_ == OperationMode::ERROR_PROTOCOL || mode_ == ERROR_TIMER;
  }
 
  bool is_timeout() { return mode_ == OperationMode::ERROR_TIMEOUT; }
 
  bool is_protocol_error() { return mode_ == OperationMode::ERROR_PROTOCOL; }
 
  bool is_timer_error() { return mode_ == OperationMode::ERROR_TIMER; }
 
  bool is_active() { return mode_ == LISTEN || mode_ == READ || mode_ == WRITE; }
 
  OperationMode get_mode() { return mode_; }
 
  void debug_data(OpenthermData &data);
  void debug_error(OpenThermError &error) const;
  void report_and_reset_timer_error();
 
  const char *protocol_error_to_str(ProtocolErrorType error_type);
  const char *timer_error_to_str(TimerErrorType error_type);
  const char *message_type_to_str(MessageType message_type);
  const char *operation_mode_to_str(OperationMode mode);
  const char *message_id_to_str(MessageId id);
 
#ifdef USE_ESP32
  static bool timer_isr(gptimer_handle_t timer, const gptimer_alarm_event_data_t *edata, void *user_ctx);
#else
  static bool timer_isr(OpenTherm *arg);
#endif
 
#ifdef ESP8266
  static void esp8266_timer_isr();
#endif
 
 private:
  InternalGPIOPin *in_pin_;
  InternalGPIOPin *out_pin_;
  ISRInternalGPIOPin isr_in_pin_;
  ISRInternalGPIOPin isr_out_pin_;
 
#ifdef USE_ESP32
  gptimer_handle_t timer_handle_{nullptr};
  gptimer_alarm_config_t alarm_config_{
      .alarm_count = 0,
      .reload_count = 0,
      .flags = {.auto_reload_on_alarm = true},
  };
#endif
 
  OperationMode mode_;
  ProtocolErrorType error_type_;
  uint32_t capture_;
  uint8_t clock_;
  uint32_t data_;
  uint8_t bit_pos_;
  int32_t timeout_counter_;  // <0 no timeout
  int32_t device_timeout_;
 
#ifdef USE_ESP32
  esp_err_t timer_error_ = ESP_OK;
  TimerErrorType timer_error_type_ = TimerErrorType::NO_TIMER_ERROR;
 
  bool init_esp32_timer_();
  void start_esp32_timer_(uint64_t alarm_value);
#endif
 
  void stop_timer_();
 
  void read_();               // data detected start reading
  void start_read_timer_();   // reading timer_ to sample at 1/5 of manchester code bit length (at 5kHz)
  void start_write_timer_();  // writing timer_ to send manchester code (at 2kHz)
  bool check_parity_(uint32_t val);
 
  void bit_read_(uint8_t value);
  ProtocolErrorType verify_stop_bit_(uint8_t value);
  void write_bit_(uint8_t high, uint8_t clock);
 
#ifdef ESP8266
  // ESP8266 timer can accept callback with no parameters, so we have this hack to save a static instance of OpenTherm
  static OpenTherm *instance;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
#endif
};
 
}  // namespace esphome::opentherm