ESPHome  2022.9.1
dht12.cpp
Go to the documentation of this file.
1 // Implementation based on:
2 // - ESPEasy: https://github.com/letscontrolit/ESPEasy/blob/mega/src/_P034_DHT12.ino
3 // - DHT12_sensor_library: https://github.com/xreef/DHT12_sensor_library/blob/master/DHT12.cpp
4 
5 #include "dht12.h"
6 #include "esphome/core/log.h"
7 
8 namespace esphome {
9 namespace dht12 {
10 
11 static const char *const TAG = "dht12";
12 
14  uint8_t data[5];
15  if (!this->read_data_(data)) {
16  this->status_set_warning();
17  return;
18  }
19  const uint16_t raw_temperature = uint16_t(data[2]) * 10 + (data[3] & 0x7F);
20  float temperature = raw_temperature / 10.0f;
21  if ((data[3] & 0x80) != 0) {
22  // negative
23  temperature *= -1;
24  }
25 
26  const uint16_t raw_humidity = uint16_t(data[0]) * 10 + data[1];
27  float humidity = raw_humidity / 10.0f;
28 
29  ESP_LOGD(TAG, "Got temperature=%.2f°C humidity=%.2f%%", temperature, humidity);
30  if (this->temperature_sensor_ != nullptr)
31  this->temperature_sensor_->publish_state(temperature);
32  if (this->humidity_sensor_ != nullptr)
33  this->humidity_sensor_->publish_state(humidity);
34  this->status_clear_warning();
35 }
37  ESP_LOGCONFIG(TAG, "Setting up DHT12...");
38  uint8_t data[5];
39  if (!this->read_data_(data)) {
40  this->mark_failed();
41  return;
42  }
43 }
45  ESP_LOGD(TAG, "DHT12:");
46  LOG_I2C_DEVICE(this);
47  if (this->is_failed()) {
48  ESP_LOGE(TAG, "Communication with DHT12 failed!");
49  }
50  LOG_SENSOR(" ", "Temperature", this->temperature_sensor_);
51  LOG_SENSOR(" ", "Humidity", this->humidity_sensor_);
52 }
54 bool DHT12Component::read_data_(uint8_t *data) {
55  if (!this->read_bytes(0, data, 5)) {
56  ESP_LOGW(TAG, "Updating DHT12 failed!");
57  return false;
58  }
59 
60  uint8_t checksum = data[0] + data[1] + data[2] + data[3];
61  if (data[4] != checksum) {
62  ESP_LOGW(TAG, "DHT12 Checksum invalid!");
63  return false;
64  }
65 
66  return true;
67 }
68 
69 } // namespace dht12
70 } // namespace esphome
const float DATA
For components that import data from directly connected sensors like DHT.
Definition: component.cpp:18
sensor::Sensor * humidity_sensor_
Definition: dht12.h:24
bool read_data_(uint8_t *data)
Definition: dht12.cpp:54
bool read_bytes(uint8_t a_register, uint8_t *data, uint8_t len)
Definition: i2c.h:68
float temperature
Definition: qmp6988.h:71
sensor::Sensor * temperature_sensor_
Definition: dht12.h:23
void update() override
Definition: dht12.cpp:13
void setup() override
Definition: dht12.cpp:36
void status_clear_warning()
Definition: component.cpp:148
float get_setup_priority() const override
Definition: dht12.cpp:53
void publish_state(float state)
Publish a new state to the front-end.
Definition: sensor.cpp:72
uint8_t checksum
Definition: bl0939.h:35
void status_set_warning()
Definition: component.cpp:140
void dump_config() override
Definition: dht12.cpp:44
virtual void mark_failed()
Mark this component as failed.
Definition: component.cpp:111
Definition: a4988.cpp:4