Add support for Sensirion STS3x Temperature sensors

esphome/components/sts3x/sensor.py

@@ -0,0 +1,26 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import i2c, sensor
+from esphome.const import CONF_ID, CONF_TEMPERATURE, \
+    ICON_THERMOMETER, UNIT_CELSIUS
+
+DEPENDENCIES = ['i2c']
+
+sts3x_ns = cg.esphome_ns.namespace('sts3x')
+STS3XComponent = sts3x_ns.class_('STS3XComponent', cg.PollingComponent, i2c.I2CDevice)
+
+CONFIG_SCHEMA = cv.Schema({
+    cv.GenerateID(): cv.declare_id(STS3XComponent),
+    cv.Required(CONF_TEMPERATURE): sensor.sensor_schema(UNIT_CELSIUS, ICON_THERMOMETER, 1),
+}).extend(cv.polling_component_schema('60s')).extend(i2c.i2c_device_schema(0x4A))
+
+
+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))
+

esphome/components/sts3x/sts3x.cpp

@@ -0,0 +1,117 @@
+#include "sts3x.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace sts3x {
+
+static const char *TAG = "sts3x";
+
+static const uint16_t STS3X_COMMAND_READ_SERIAL_NUMBER = 0x3780;
+static const uint16_t STS3X_COMMAND_READ_STATUS = 0xF32D;
+static const uint16_t STS3X_COMMAND_CLEAR_STATUS = 0x3041;
+static const uint16_t STS3X_COMMAND_HEATER_ENABLE = 0x306D;
+static const uint16_t STS3X_COMMAND_HEATER_DISABLE = 0x3066;
+static const uint16_t STS3X_COMMAND_SOFT_RESET = 0x30A2;
+static const uint16_t STS3X_COMMAND_POLLING_H = 0x2400;
+static const uint16_t STS3X_COMMAND_FETCH_DATA = 0xE000;
+
+void STS3XComponent::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up STS3x...");
+  if (!this->write_command_(STS3X_COMMAND_READ_SERIAL_NUMBER)) {
+    this->mark_failed();
+    return;
+  }
+
+  uint16_t raw_serial_number[2];
+  if (!this->read_data_(raw_serial_number, 1)) {
+    this->mark_failed();
+    return;
+  }
+  uint32_t serial_number = (uint32_t(raw_serial_number[0]) << 16) | uint32_t(raw_serial_number[1]);
+  ESP_LOGV(TAG, "    Serial Number: 0x%08X", serial_number);
+}
+void STS3XComponent::dump_config() {
+  ESP_LOGCONFIG(TAG, "STS3x:");
+  LOG_I2C_DEVICE(this);
+  if (this->is_failed()) {
+    ESP_LOGE(TAG, "Communication with ST3x failed!");
+  }
+  LOG_UPDATE_INTERVAL(this);
+
+  LOG_SENSOR("  ", "Temperature", this->temperature_sensor_);
+}
+float STS3XComponent::get_setup_priority() const { return setup_priority::DATA; }
+void STS3XComponent::update() {
+  if (!this->write_command_(STS3X_COMMAND_POLLING_H))
+    return;
+
+  this->set_timeout(50, [this]() {
+    uint16_t raw_data[1];
+    if (!this->read_data_(raw_data, 1)) {
+      this->status_set_warning();
+      return;
+    }
+
+    float temperature = 175.0f * float(raw_data[0]) / 65535.0f - 45.0f;
+
+    ESP_LOGD(TAG, "Got temperature=%.2f°C", temperature);
+    if (this->temperature_sensor_ != nullptr)
+      this->temperature_sensor_->publish_state(temperature);
+    this->status_clear_warning();
+  });
+}
+
+bool STS3XComponent::write_command_(uint16_t command) {
+  // Warning ugly, trick the I2Ccomponent base by setting register to the first 8 bit.
+  return this->write_byte(command >> 8, command & 0xFF);
+}
+
+uint8_t sts3x_crc(uint8_t data1, uint8_t data2) {
+  uint8_t bit;
+  uint8_t crc = 0xFF;
+
+  crc ^= data1;
+  for (bit = 8; bit > 0; --bit) {
+    if (crc & 0x80)
+      crc = (crc << 1) ^ 0x131;
+    else
+      crc = (crc << 1);
+  }
+
+  crc ^= data2;
+  for (bit = 8; bit > 0; --bit) {
+    if (crc & 0x80)
+      crc = (crc << 1) ^ 0x131;
+    else
+      crc = (crc << 1);
+  }
+
+  return crc;
+}
+
+bool STS3XComponent::read_data_(uint16_t *data, uint8_t len) {
+  const uint8_t num_bytes = len * 3;
+  auto *buf = new uint8_t[num_bytes];
+
+  if (!this->parent_->raw_receive(this->address_, buf, num_bytes)) {
+    delete[](buf);
+    return false;
+  }
+
+  for (uint8_t i = 0; i < len; i++) {
+    const uint8_t j = 3 * i;
+    uint8_t crc = sts3x_crc(buf[j], buf[j + 1]);
+    if (crc != buf[j + 2]) {
+      ESP_LOGE(TAG, "CRC8 Checksum invalid! 0x%02X != 0x%02X", buf[j + 2], crc);
+      delete[](buf);
+      return false;
+    }
+    data[i] = (buf[j] << 8) | buf[j + 1];
+  }
+
+  delete[](buf);
+  return true;
+}
+
+}  // namespace sts3x
+}  // namespace esphome

esphome/components/sts3x/sts3x.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/components/i2c/i2c.h"
+
+namespace esphome {
+namespace sts3x {
+
+/// This class implements support for the ST3x-DIS family of temperature i2c sensors.
+class STS3XComponent : public PollingComponent, public i2c::I2CDevice {
+ public:
+  void set_temperature_sensor(sensor::Sensor *temperature_sensor) { temperature_sensor_ = temperature_sensor; }
+  void set_humidity_sensor(sensor::Sensor *humidity_sensor) { humidity_sensor_ = humidity_sensor; }
+
+  void setup() override;
+  void dump_config() override;
+  float get_setup_priority() const override;
+  void update() override;
+
+ protected:
+  bool write_command_(uint16_t command);
+  bool read_data_(uint16_t *data, uint8_t len);
+
+  sensor::Sensor *temperature_sensor_;
+  sensor::Sensor *humidity_sensor_;
+};
+
+}  // namespace sts3x
+}  // namespace esphome