esphome/esphome/components/mhz19/mhz19.cpp

107 lines
3.5 KiB
C++

#include "mhz19.h"
#include "esphome/core/log.h"
namespace esphome {
namespace mhz19 {
static const char *const TAG = "mhz19";
static const uint8_t MHZ19_REQUEST_LENGTH = 8;
static const uint8_t MHZ19_RESPONSE_LENGTH = 9;
static const uint8_t MHZ19_COMMAND_GET_PPM[] = {0xFF, 0x01, 0x86, 0x00, 0x00, 0x00, 0x00, 0x00};
static const uint8_t MHZ19_COMMAND_ABC_ENABLE[] = {0xFF, 0x01, 0x79, 0xA0, 0x00, 0x00, 0x00, 0x00};
static const uint8_t MHZ19_COMMAND_ABC_DISABLE[] = {0xFF, 0x01, 0x79, 0x00, 0x00, 0x00, 0x00, 0x00};
static const uint8_t MHZ19_COMMAND_CALIBRATE_ZERO[] = {0xFF, 0x01, 0x87, 0x00, 0x00, 0x00, 0x00, 0x00};
uint8_t mhz19_checksum(const uint8_t *command) {
uint8_t sum = 0;
for (uint8_t i = 1; i < MHZ19_REQUEST_LENGTH; i++) {
sum += command[i];
}
return 0xFF - sum + 0x01;
}
void MHZ19Component::setup() {
if (this->abc_boot_logic_ == MHZ19_ABC_ENABLED) {
this->abc_enable();
} else if (this->abc_boot_logic_ == MHZ19_ABC_DISABLED) {
this->abc_disable();
}
}
void MHZ19Component::update() {
uint8_t response[MHZ19_RESPONSE_LENGTH];
if (!this->mhz19_write_command_(MHZ19_COMMAND_GET_PPM, response)) {
ESP_LOGW(TAG, "Reading data from MHZ19 failed!");
this->status_set_warning();
return;
}
if (response[0] != 0xFF || response[1] != 0x86) {
ESP_LOGW(TAG, "Invalid preamble from MHZ19!");
this->status_set_warning();
return;
}
uint8_t checksum = mhz19_checksum(response);
if (response[8] != checksum) {
ESP_LOGW(TAG, "MHZ19 Checksum doesn't match: 0x%02X!=0x%02X", response[8], checksum);
this->status_set_warning();
return;
}
this->status_clear_warning();
const uint16_t ppm = (uint16_t(response[2]) << 8) | response[3];
const int temp = int(response[4]) - 40;
const uint8_t status = response[5];
ESP_LOGD(TAG, "MHZ19 Received CO₂=%uppm Temperature=%d°C Status=0x%02X", ppm, temp, status);
if (this->co2_sensor_ != nullptr)
this->co2_sensor_->publish_state(ppm);
if (this->temperature_sensor_ != nullptr)
this->temperature_sensor_->publish_state(temp);
}
void MHZ19Component::calibrate_zero() {
ESP_LOGD(TAG, "MHZ19 Calibrating zero point");
this->mhz19_write_command_(MHZ19_COMMAND_CALIBRATE_ZERO, nullptr);
}
void MHZ19Component::abc_enable() {
ESP_LOGD(TAG, "MHZ19 Enabling automatic baseline calibration");
this->mhz19_write_command_(MHZ19_COMMAND_ABC_ENABLE, nullptr);
}
void MHZ19Component::abc_disable() {
ESP_LOGD(TAG, "MHZ19 Disabling automatic baseline calibration");
this->mhz19_write_command_(MHZ19_COMMAND_ABC_DISABLE, nullptr);
}
bool MHZ19Component::mhz19_write_command_(const uint8_t *command, uint8_t *response) {
// Empty RX Buffer
while (this->available())
this->read();
this->write_array(command, MHZ19_REQUEST_LENGTH);
this->write_byte(mhz19_checksum(command));
this->flush();
if (response == nullptr)
return true;
return this->read_array(response, MHZ19_RESPONSE_LENGTH);
}
float MHZ19Component::get_setup_priority() const { return setup_priority::DATA; }
void MHZ19Component::dump_config() {
ESP_LOGCONFIG(TAG, "MH-Z19:");
LOG_SENSOR(" ", "CO2", this->co2_sensor_);
LOG_SENSOR(" ", "Temperature", this->temperature_sensor_);
this->check_uart_settings(9600);
if (this->abc_boot_logic_ == MHZ19_ABC_ENABLED) {
ESP_LOGCONFIG(TAG, " Automatic baseline calibration enabled on boot");
} else if (this->abc_boot_logic_ == MHZ19_ABC_DISABLED) {
ESP_LOGCONFIG(TAG, " Automatic baseline calibration disabled on boot");
}
}
} // namespace mhz19
} // namespace esphome