Files
esphome/esphome/components/hc8/hc8.cpp
2025-11-20 09:24:45 -05:00

100 lines
2.8 KiB
C++

#include "hc8.h"
#include "esphome/core/application.h"
#include "esphome/core/helpers.h"
#include "esphome/core/log.h"
#include <array>
namespace esphome::hc8 {
static const char *const TAG = "hc8";
static const std::array<uint8_t, 5> HC8_COMMAND_GET_PPM{0x64, 0x69, 0x03, 0x5E, 0x4E};
static const std::array<uint8_t, 3> HC8_COMMAND_CALIBRATE_PREAMBLE{0x11, 0x03, 0x03};
void HC8Component::setup() {
// send an initial query to the device, this will
// get it out of "active output mode", where it
// generates data every second
this->write_array(HC8_COMMAND_GET_PPM);
this->flush();
// ensure the buffer is empty
while (this->available())
this->read();
}
void HC8Component::update() {
uint32_t now_ms = App.get_loop_component_start_time();
uint32_t warmup_ms = this->warmup_seconds_ * 1000;
if (now_ms < warmup_ms) {
ESP_LOGW(TAG, "HC8 warming up, %" PRIu32 " s left", (warmup_ms - now_ms) / 1000);
this->status_set_warning();
return;
}
while (this->available())
this->read();
this->write_array(HC8_COMMAND_GET_PPM);
this->flush();
// the sensor is a bit slow in responding, so trying to
// read immediately after sending a query will timeout
this->set_timeout(50, [this]() {
std::array<uint8_t, 14> response;
if (!this->read_array(response.data(), response.size())) {
ESP_LOGW(TAG, "Reading data from HC8 failed!");
this->status_set_warning();
return;
}
if (response[0] != 0x64 || response[1] != 0x69) {
ESP_LOGW(TAG, "Invalid preamble from HC8!");
this->status_set_warning();
return;
}
if (crc16(response.data(), 12) != encode_uint16(response[13], response[12])) {
ESP_LOGW(TAG, "HC8 Checksum mismatch");
this->status_set_warning();
return;
}
this->status_clear_warning();
const uint16_t ppm = encode_uint16(response[5], response[4]);
ESP_LOGD(TAG, "HC8 Received CO₂=%uppm", ppm);
if (this->co2_sensor_ != nullptr)
this->co2_sensor_->publish_state(ppm);
});
}
void HC8Component::calibrate(uint16_t baseline) {
ESP_LOGD(TAG, "HC8 Calibrating baseline to %uppm", baseline);
std::array<uint8_t, 6> command{};
std::copy(begin(HC8_COMMAND_CALIBRATE_PREAMBLE), end(HC8_COMMAND_CALIBRATE_PREAMBLE), begin(command));
command[3] = baseline >> 8;
command[4] = baseline;
command[5] = 0;
// the last byte is a checksum over the data
for (uint8_t i = 0; i < 5; ++i)
command[5] -= command[i];
this->write_array(command);
this->flush();
}
float HC8Component::get_setup_priority() const { return setup_priority::DATA; }
void HC8Component::dump_config() {
ESP_LOGCONFIG(TAG, "HC8:");
LOG_SENSOR(" ", "CO2", this->co2_sensor_);
this->check_uart_settings(9600);
ESP_LOGCONFIG(TAG, " Warmup time: %" PRIu32 " s", this->warmup_seconds_);
}
} // namespace esphome::hc8