Add AHT10 sensor (#949)

esphome/components/aht10/aht10.cpp

@@ -0,0 +1,127 @@
+// Implementation based on:
+//  - AHT10: https://github.com/Thinary/AHT10
+//  - Official Datasheet (cn):
+//  http://www.aosong.com/userfiles/files/media/aht10%E8%A7%84%E6%A0%BC%E4%B9%A6v1_1%EF%BC%8820191015%EF%BC%89.pdf
+//  - Unofficial Translated Datasheet (en):
+//  https://wiki.liutyi.info/download/attachments/30507639/Aosong_AHT10_en_draft_0c.pdf
+//
+// When configured for humidity, the log 'Components should block for at most 20-30ms in loop().' will be generated in
+// verbose mode. This is due to technical specs of the sensor and can not be avoided.
+//
+// According to the datasheet, the component is supposed to respond in more than 75ms. In fact, it can answer almost
+// immediately for temperature. But for humidity, it takes >90ms to get a valid data. From experience, we have best
+// results making successive requests; the current implementation make 3 attemps with a delay of 30ms each time.
+
+#include "aht10.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace aht10 {
+
+static const char *TAG = "aht10";
+static const uint8_t AHT10_CALIBRATE_CMD[] = {0xE1};
+static const uint8_t AHT10_MEASURE_CMD[] = {0xAC, 0x33, 0x00};
+static const uint8_t AHT10_DEFAULT_DELAY = 5;    // ms, for calibration and temperature measurement
+static const uint8_t AHT10_HUMIDITY_DELAY = 30;  // ms
+static const uint8_t AHT10_ATTEMPS = 3;          // safety margin, normally 3 attemps are enough: 3*30=90ms
+
+void AHT10Component::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up AHT10...");
+
+  if (!this->write_bytes(0, AHT10_CALIBRATE_CMD, sizeof(AHT10_CALIBRATE_CMD))) {
+    ESP_LOGE(TAG, "Communication with AHT10 failed!");
+    this->mark_failed();
+    return;
+  }
+  uint8_t data;
+  if (!this->read_byte(0, &data, AHT10_DEFAULT_DELAY)) {
+    ESP_LOGD(TAG, "Communication with AHT10 failed!");
+    this->mark_failed();
+    return;
+  }
+  if ((data & 0x68) != 0x08) {  // Bit[6:5] = 0b00, NORMAL mode and Bit[3] = 0b1, CALIBRATED
+    ESP_LOGE(TAG, "AHT10 calibration failed!");
+    this->mark_failed();
+    return;
+  }
+
+  ESP_LOGV(TAG, "AHT10 calibrated");
+}
+
+void AHT10Component::update() {
+  if (!this->write_bytes(0, AHT10_MEASURE_CMD, sizeof(AHT10_MEASURE_CMD))) {
+    ESP_LOGE(TAG, "Communication with AHT10 failed!");
+    this->status_set_warning();
+    return;
+  }
+  uint8_t data[6];
+  uint8_t delay = AHT10_DEFAULT_DELAY;
+  if (this->humidity_sensor_ != nullptr)
+    delay = AHT10_HUMIDITY_DELAY;
+  for (int i = 0; i < AHT10_ATTEMPS; ++i) {
+    ESP_LOGVV(TAG, "Attemps %u at %6ld", i, millis());
+    if (!this->read_bytes(0, data, 6, delay)) {
+      ESP_LOGD(TAG, "Communication with AHT10 failed, waiting...");
+    } else if ((data[0] & 0x80) == 0x80) {  // Bit[7] = 0b1, device is busy
+      ESP_LOGD(TAG, "AHT10 is busy, waiting...");
+    } else if (data[1] == 0x0 && data[2] == 0x0 && (data[3] >> 4) == 0x0) {
+      // Unrealistic humidity (0x0)
+      if (this->humidity_sensor_ == nullptr) {
+        ESP_LOGVV(TAG, "ATH10 Unrealistic humidity (0x0), but humidity is not required");
+        break;
+      } else {
+        ESP_LOGD(TAG, "ATH10 Unrealistic humidity (0x0), retrying...");
+        if (!this->write_bytes(0, AHT10_MEASURE_CMD, sizeof(AHT10_MEASURE_CMD))) {
+          ESP_LOGE(TAG, "Communication with AHT10 failed!");
+          this->status_set_warning();
+          return;
+        }
+      }
+    } else {
+      // data is valid, we can break the loop
+      ESP_LOGVV(TAG, "Answer at %6ld", millis());
+      break;
+    }
+  }
+  if ((data[0] & 0x80) == 0x80) {
+    ESP_LOGE(TAG, "Measurements reading timed-out!");
+    this->status_set_warning();
+    return;
+  }
+
+  uint32_t raw_temperature = ((data[3] & 0x0F) << 16) | (data[4] << 8) | data[5];
+  uint32_t raw_humidity = ((data[1] << 16) | (data[2] << 8) | data[3]) >> 4;
+
+  float temperature = ((200.0 * (float) raw_temperature) / 1048576.0) - 50.0;
+  float humidity;
+  if (raw_humidity == 0) {  // unrealistic value
+    humidity = NAN;
+  } else {
+    humidity = (float) raw_humidity * 100.0 / 1048576.0;
+  }
+
+  if (this->temperature_sensor_ != nullptr) {
+    this->temperature_sensor_->publish_state(temperature);
+  }
+  if (this->humidity_sensor_ != nullptr) {
+    if (isnan(humidity))
+      ESP_LOGW(TAG, "Invalid humidity! Sensor reported 0%% Hum");
+    this->humidity_sensor_->publish_state(humidity);
+  }
+  this->status_clear_warning();
+}
+
+float AHT10Component::get_setup_priority() const { return setup_priority::DATA; }
+
+void AHT10Component::dump_config() {
+  ESP_LOGCONFIG(TAG, "AHT10:");
+  LOG_I2C_DEVICE(this);
+  if (this->is_failed()) {
+    ESP_LOGE(TAG, "Communication with AHT10 failed!");
+  }
+  LOG_SENSOR("  ", "Temperature", this->temperature_sensor_);
+  LOG_SENSOR("  ", "Humidity", this->humidity_sensor_);
+}
+
+}  // namespace aht10
+}  // namespace esphome

esphome/components/aht10/aht10.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/components/i2c/i2c.h"
+
+namespace esphome {
+namespace aht10 {
+
+class AHT10Component : public PollingComponent, public i2c::I2CDevice {
+ public:
+  void setup() override;
+  void update() override;
+  void dump_config() override;
+  float get_setup_priority() const override;
+
+  void set_temperature_sensor(sensor::Sensor *temperature_sensor) { temperature_sensor_ = temperature_sensor; }
+  void set_humidity_sensor(sensor::Sensor *humidity_sensor) { humidity_sensor_ = humidity_sensor; }
+
+ protected:
+  sensor::Sensor *temperature_sensor_;
+  sensor::Sensor *humidity_sensor_;
+};
+
+}  // namespace aht10
+}  // namespace esphome

esphome/components/aht10/sensor.py

@@ -0,0 +1,30 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import i2c, sensor
+from esphome.const import CONF_HUMIDITY, CONF_ID, CONF_TEMPERATURE, \
+    UNIT_CELSIUS, ICON_THERMOMETER, ICON_WATER_PERCENT, UNIT_PERCENT
+
+DEPENDENCIES = ['i2c']
+
+aht10_ns = cg.esphome_ns.namespace('aht10')
+AHT10Component = aht10_ns.class_('AHT10Component', cg.PollingComponent, i2c.I2CDevice)
+
+CONFIG_SCHEMA = cv.Schema({
+    cv.GenerateID(): cv.declare_id(AHT10Component),
+    cv.Optional(CONF_TEMPERATURE): sensor.sensor_schema(UNIT_CELSIUS, ICON_THERMOMETER, 2),
+    cv.Optional(CONF_HUMIDITY): sensor.sensor_schema(UNIT_PERCENT, ICON_WATER_PERCENT, 2),
+}).extend(cv.polling_component_schema('60s')).extend(i2c.i2c_device_schema(0x38))
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+    yield i2c.register_i2c_device(var, config)
+
+    if CONF_TEMPERATURE in config:
+        sens = yield sensor.new_sensor(config[CONF_TEMPERATURE])
+        cg.add(var.set_temperature_sensor(sens))
+
+    if CONF_HUMIDITY in config:
+        sens = yield sensor.new_sensor(config[CONF_HUMIDITY])
+        cg.add(var.set_humidity_sensor(sens))

tests/test3.yaml

@@ -221,6 +221,11 @@ sensor:
   - platform: homeassistant
     entity_id: sensor.hello_world
     id: ha_hello_world
+  - platform: aht10  
+    temperature:
+      name: "Temperature"
+    humidity:
+      name: "Humidity"
   - platform: am2320
     temperature:
       name: "Temperature"