xiaomi_miscale.cpp

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#include "xiaomi_miscale.h"
#include "esphome/components/ble_device_base/ble_device.h"
#include "esphome/core/log.h"
 
namespace esphome::xiaomi_miscale {
 
static const char *const TAG = "xiaomi_miscale";
 
void XiaomiMiscale::dump_config() {
  ESP_LOGCONFIG(TAG, "Xiaomi Miscale");
  LOG_SENSOR("  ", "Weight", this->weight_);
  LOG_SENSOR("  ", "Impedance", this->impedance_);
}
 
bool XiaomiMiscale::parse_device(const ble_device_base::ESPBTDevice &device) {
  if (device.address_uint64() != this->address_) {
    ESP_LOGVV(TAG, "parse_device(): unknown MAC address.");
    return false;
  }
  char addr_buf[MAC_ADDRESS_PRETTY_BUFFER_SIZE];
  const char *addr_str = device.address_str_to(addr_buf);
  ESP_LOGVV(TAG, "parse_device(): MAC address %s found.", addr_str);
 
  bool success = false;
  for (auto &service_data : device.get_service_datas()) {
    auto res = parse_header_(service_data);
    if (!res.has_value())
      continue;
 
    if (!parse_message_(service_data.data, *res))
      continue;
 
    if (!report_results_(res, addr_str))
      continue;
 
    if (res->weight.has_value() && this->weight_ != nullptr)
      this->weight_->publish_state(*res->weight);
 
    if (this->impedance_ != nullptr) {
      if (res->version == 1) {
        ESP_LOGW(TAG, "Impedance is only supported on version 2. Your scale was identified as version 1.");
      } else {
        if (res->impedance.has_value()) {
          this->impedance_->publish_state(*res->impedance);
        } else {
          if (clear_impedance_)
            this->impedance_->publish_state(NAN);
        }
      }
    }
    success = true;
  }
 
  return success;
}
 
optional<ParseResult> XiaomiMiscale::parse_header_(const ble_device_base::ServiceData &service_data) {
  ParseResult result;
  if (service_data.uuid == ble_device_base::ESPBTUUID::from_uint16(0x181D) && service_data.data.size() == 10) {
    result.version = 1;
  } else if (service_data.uuid == ble_device_base::ESPBTUUID::from_uint16(0x181B) && service_data.data.size() == 13) {
    result.version = 2;
  } else {
    char uuid_buf[ble_device_base::UUID_STR_LEN];
    ESP_LOGVV(TAG,
              "parse_header(): Couldn't identify scale version or data size was not correct. UUID: %s, data_size: %d",
              service_data.uuid.to_str(uuid_buf), service_data.data.size());
    return {};
  }
 
  return result;
}
 
bool XiaomiMiscale::parse_message_(const std::vector<uint8_t> &message, ParseResult &result) {
  if (result.version == 1) {
    return parse_message_v1_(message, result);
  } else {
    return parse_message_v2_(message, result);
  }
}
 
bool XiaomiMiscale::parse_message_v1_(const std::vector<uint8_t> &message, ParseResult &result) {
  // message size is checked in parse_header
  // 1-2 Weight (MISCALE 181D)
  // 3-4 Years (MISCALE 181D)
  // 5 month (MISCALE 181D)
  // 6 day (MISCALE 181D)
  // 7 hour (MISCALE 181D)
  // 8 minute (MISCALE 181D)
  // 9 second (MISCALE 181D)
 
  const uint8_t *data = message.data();
 
  // weight, 2 bytes, 16-bit  unsigned integer, 1 kg
  const int16_t weight = uint16_t(data[1]) | (uint16_t(data[2]) << 8);
  if (data[0] == 0x22 || data[0] == 0xa2) {
    result.weight = weight * 0.01f / 2.0f;  // unit 'kg'
  } else if (data[0] == 0x12 || data[0] == 0xb2) {
    result.weight = weight * 0.01f * 0.6f;  // unit 'jin'
  } else if (data[0] == 0x03 || data[0] == 0xb3) {
    result.weight = weight * 0.01f * 0.453592f;  // unit 'lbs'
  }
 
  return true;
}
 
bool XiaomiMiscale::parse_message_v2_(const std::vector<uint8_t> &message, ParseResult &result) {
  // message size is checked in parse_header
  // 2-3 Years (MISCALE 2 181B)
  // 4 month (MISCALE 2 181B)
  // 5 day (MISCALE 2 181B)
  // 6 hour (MISCALE 2 181B)
  // 7 minute (MISCALE 2 181B)
  // 8 second (MISCALE 2 181B)
  // 9-10 impedance (MISCALE 2 181B)
  // 11-12 weight (MISCALE 2 181B)
 
  const uint8_t *data = message.data();
 
  bool has_impedance = ((data[1] & (1 << 1)) != 0);
  bool is_stabilized = ((data[1] & (1 << 5)) != 0);
  bool load_removed = ((data[1] & (1 << 7)) != 0);
 
  if (!is_stabilized || load_removed) {
    return false;
  }
 
  // weight, 2 bytes, 16-bit  unsigned integer, 1 kg
  const int16_t weight = uint16_t(data[11]) | (uint16_t(data[12]) << 8);
  if (data[0] == 0x02) {
    result.weight = weight * 0.01f / 2.0f;  // unit 'kg'
  } else if (data[0] == 0x03) {
    result.weight = weight * 0.01f * 0.453592f;  // unit 'lbs'
  }
 
  if (has_impedance) {
    // impedance, 2 bytes, 16-bit
    const int16_t impedance = uint16_t(data[9]) | (uint16_t(data[10]) << 8);
    result.impedance = impedance;
 
    if (impedance == 0 || impedance >= 3000) {
      return false;
    }
  }
 
  return true;
}
 
bool XiaomiMiscale::report_results_(const optional<ParseResult> &result, const char *address) {
  if (!result.has_value()) {
    ESP_LOGVV(TAG, "report_results(): no results available.");
    return false;
  }
 
  ESP_LOGD(TAG, "Got Xiaomi Miscale v%d (%s):", result->version, address);
 
  if (result->weight.has_value()) {
    ESP_LOGD(TAG, "  Weight: %.2fkg", *result->weight);
  }
  if (result->impedance.has_value()) {
    ESP_LOGD(TAG, "  Impedance: %.0fohm", *result->impedance);
  }
 
  return true;
}
 
}  // namespace esphome::xiaomi_miscale