esphome/esphome/components/senseair/senseair.cpp

91 lines
2.7 KiB
C++

#include "senseair.h"
#include "esphome/core/log.h"
namespace esphome {
namespace senseair {
static const char *TAG = "senseair";
static const uint8_t SENSEAIR_REQUEST_LENGTH = 8;
static const uint8_t SENSEAIR_RESPONSE_LENGTH = 13;
static const uint8_t SENSEAIR_COMMAND_GET_PPM[] = {0xFE, 0x04, 0x00, 0x00, 0x00, 0x04, 0xE5, 0xC6};
void SenseAirComponent::update() {
uint8_t response[SENSEAIR_RESPONSE_LENGTH];
if (!this->senseair_write_command_(SENSEAIR_COMMAND_GET_PPM, response)) {
ESP_LOGW(TAG, "Reading data from SenseAir failed!");
this->status_set_warning();
return;
}
if (response[0] != 0xFE || response[1] != 0x04) {
ESP_LOGW(TAG, "Invalid preamble from SenseAir! %02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x %02x",
response[0], response[1], response[2], response[3], response[4], response[5], response[6], response[7],
response[8], response[9], response[10], response[11], response[12]);
this->status_set_warning();
while (this->available()) {
uint8_t b;
if (this->read_byte(&b)) {
ESP_LOGV(TAG, " ... %02x", b);
} else {
ESP_LOGV(TAG, " ... nothing read");
}
}
return;
}
uint16_t calc_checksum = this->senseair_checksum_(response, 11);
uint16_t resp_checksum = (uint16_t(response[12]) << 8) | response[11];
if (resp_checksum != calc_checksum) {
ESP_LOGW(TAG, "SenseAir checksum doesn't match: 0x%02X!=0x%02X", resp_checksum, calc_checksum);
this->status_set_warning();
return;
}
this->status_clear_warning();
const uint8_t length = response[2];
const uint16_t status = (uint16_t(response[3]) << 8) | response[4];
const uint16_t ppm = (uint16_t(response[length + 1]) << 8) | response[length + 2];
ESP_LOGD(TAG, "SenseAir Received CO₂=%uppm Status=0x%02X", ppm, status);
if (this->co2_sensor_ != nullptr)
this->co2_sensor_->publish_state(ppm);
}
uint16_t SenseAirComponent::senseair_checksum_(uint8_t *ptr, uint8_t length) {
uint16_t crc = 0xFFFF;
uint8_t i;
while (length--) {
crc ^= *ptr++;
for (i = 0; i < 8; i++) {
if ((crc & 0x01) != 0) {
crc >>= 1;
crc ^= 0xA001;
} else {
crc >>= 1;
}
}
}
return crc;
}
bool SenseAirComponent::senseair_write_command_(const uint8_t *command, uint8_t *response) {
this->flush();
this->write_array(command, SENSEAIR_REQUEST_LENGTH);
if (response == nullptr)
return true;
bool ret = this->read_array(response, SENSEAIR_RESPONSE_LENGTH);
this->flush();
return ret;
}
void SenseAirComponent::dump_config() {
ESP_LOGCONFIG(TAG, "SenseAir:");
LOG_SENSOR(" ", "CO2", this->co2_sensor_);
this->check_uart_settings(9600);
}
} // namespace senseair
} // namespace esphome