SCD30 fixes and improvements (#962)

* SCD30 improvements

esphome/components/scd30/scd30.cpp

@@ -8,21 +8,25 @@ static const char *TAG = "scd30";
 
 static const uint16_t SCD30_CMD_GET_FIRMWARE_VERSION = 0xd100;
 static const uint16_t SCD30_CMD_START_CONTINUOUS_MEASUREMENTS = 0x0010;
+static const uint16_t SCD30_CMD_ALTITUDE_COMPENSATION = 0x5102;
+static const uint16_t SCD30_CMD_AUTOMATIC_SELF_CALIBRATION = 0x5306;
 static const uint16_t SCD30_CMD_GET_DATA_READY_STATUS = 0x0202;
 static const uint16_t SCD30_CMD_READ_MEASUREMENT = 0x0300;
 
 /// Commands for future use
 static const uint16_t SCD30_CMD_STOP_MEASUREMENTS = 0x0104;
 static const uint16_t SCD30_CMD_MEASUREMENT_INTERVAL = 0x4600;
-static const uint16_t SCD30_CMD_AUTOMATIC_SELF_CALIBRATION = 0x5306;
 static const uint16_t SCD30_CMD_FORCED_CALIBRATION = 0x5204;
 static const uint16_t SCD30_CMD_TEMPERATURE_OFFSET = 0x5403;
-static const uint16_t SCD30_CMD_ALTITUDE_COMPENSATION = 0x5102;
 static const uint16_t SCD30_CMD_SOFT_RESET = 0xD304;
 
 void SCD30Component::setup() {
   ESP_LOGCONFIG(TAG, "Setting up scd30...");
 
+#ifdef ARDUINO_ARCH_ESP8266
+  Wire.setClockStretchLimit(150000);
+#endif
+
   /// Firmware version identification
   if (!this->write_command_(SCD30_CMD_GET_FIRMWARE_VERSION)) {
     this->error_code_ = COMMUNICATION_FAILED;
@@ -40,12 +44,29 @@ void SCD30Component::setup() {
            uint16_t(raw_firmware_version[0] & 0xFF));
 
   /// Sensor initialization
-  if (!this->write_command_(SCD30_CMD_START_CONTINUOUS_MEASUREMENTS)) {
+  if (!this->write_command_(SCD30_CMD_START_CONTINUOUS_MEASUREMENTS, 0)) {
     ESP_LOGE(TAG, "Sensor SCD30 error starting continuous measurements.");
     this->error_code_ = MEASUREMENT_INIT_FAILED;
     this->mark_failed();
     return;
   }
+
+  // The start measurement command disables the altitude compensation, if any, so we only set it if it's turned on
+  if (this->altitude_compensation_ != 0xFFFF) {
+    if (!this->write_command_(SCD30_CMD_ALTITUDE_COMPENSATION, altitude_compensation_)) {
+      ESP_LOGE(TAG, "Sensor SCD30 error starting continuous measurements.");
+      this->error_code_ = MEASUREMENT_INIT_FAILED;
+      this->mark_failed();
+      return;
+    }
+  }
+
+  if (!this->write_command_(SCD30_CMD_AUTOMATIC_SELF_CALIBRATION, enable_asc_ ? 1 : 0)) {
+    ESP_LOGE(TAG, "Sensor SCD30 error setting automatic self calibration.");
+    this->error_code_ = MEASUREMENT_INIT_FAILED;
+    this->mark_failed();
+    return;
+  }
 }
 
 void SCD30Component::dump_config() {
@@ -67,6 +88,12 @@ void SCD30Component::dump_config() {
         break;
     }
   }
+  if (this->altitude_compensation_ == 0xFFFF) {
+    ESP_LOGCONFIG(TAG, "  Altitude compensation: OFF");
+  } else {
+    ESP_LOGCONFIG(TAG, "  Altitude compensation: %dm", this->altitude_compensation_);
+  }
+  ESP_LOGCONFIG(TAG, "  Automatic self calibration: %s", ONOFF(this->enable_asc_));
   LOG_UPDATE_INTERVAL(this);
   LOG_SENSOR("  ", "CO2", this->co2_sensor_);
   LOG_SENSOR("  ", "Temperature", this->temperature_sensor_);
@@ -130,6 +157,16 @@ bool SCD30Component::write_command_(uint16_t command) {
   return this->write_byte(command >> 8, command & 0xFF);
 }
 
+bool SCD30Component::write_command_(uint16_t command, uint16_t data) {
+  uint8_t raw[5];
+  raw[0] = command >> 8;
+  raw[1] = command & 0xFF;
+  raw[2] = data >> 8;
+  raw[3] = data & 0xFF;
+  raw[4] = sht_crc_(raw[2], raw[3]);
+  return this->write_bytes_raw(raw, 5);
+}
+
 uint8_t SCD30Component::sht_crc_(uint8_t data1, uint8_t data2) {
   uint8_t bit;
   uint8_t crc = 0xFF;

esphome/components/scd30/scd30.h

@@ -13,6 +13,8 @@ class SCD30Component : public PollingComponent, public i2c::I2CDevice {
   void set_co2_sensor(sensor::Sensor *co2) { co2_sensor_ = co2; }
   void set_humidity_sensor(sensor::Sensor *humidity) { humidity_sensor_ = humidity; }
   void set_temperature_sensor(sensor::Sensor *temperature) { temperature_sensor_ = temperature; }
+  void set_automatic_self_calibration(bool asc) { enable_asc_ = asc; }
+  void set_altitude_compensation(uint16_t altitude) { altitude_compensation_ = altitude; }
 
   void setup() override;
   void update() override;
@@ -21,6 +23,7 @@ class SCD30Component : public PollingComponent, public i2c::I2CDevice {
 
  protected:
   bool write_command_(uint16_t command);
+  bool write_command_(uint16_t command, uint16_t data);
   bool read_data_(uint16_t *data, uint8_t len);
   uint8_t sht_crc_(uint8_t data1, uint8_t data2);
 
@@ -30,6 +33,8 @@ class SCD30Component : public PollingComponent, public i2c::I2CDevice {
     MEASUREMENT_INIT_FAILED,
     UNKNOWN
   } error_code_{UNKNOWN};
+  bool enable_asc_{true};
+  uint16_t altitude_compensation_{0xFFFF};
 
   sensor::Sensor *co2_sensor_{nullptr};
   sensor::Sensor *humidity_sensor_{nullptr};

esphome/components/scd30/sensor.py

@@ -1,3 +1,4 @@
+import re
 import esphome.codegen as cg
 import esphome.config_validation as cv
 from esphome.components import i2c, sensor
@@ -10,12 +11,24 @@ DEPENDENCIES = ['i2c']
 scd30_ns = cg.esphome_ns.namespace('scd30')
 SCD30Component = scd30_ns.class_('SCD30Component', cg.PollingComponent, i2c.I2CDevice)
 
+CONF_AUTOMATIC_SELF_CALIBRATION = 'automatic_self_calibration'
+CONF_ALTITUDE_COMPENSATION = 'altitude_compensation'
+
+
+def remove_altitude_suffix(value):
+    return re.sub(r"\s*(?:m(?:\s+a\.s\.l)?)|(?:MAM?SL)$", '', value)
+
+
 CONFIG_SCHEMA = cv.Schema({
     cv.GenerateID(): cv.declare_id(SCD30Component),
     cv.Required(CONF_CO2): sensor.sensor_schema(UNIT_PARTS_PER_MILLION,
                                                 ICON_PERIODIC_TABLE_CO2, 0),
     cv.Required(CONF_TEMPERATURE): sensor.sensor_schema(UNIT_CELSIUS, ICON_THERMOMETER, 1),
     cv.Required(CONF_HUMIDITY): sensor.sensor_schema(UNIT_PERCENT, ICON_WATER_PERCENT, 1),
+    cv.Optional(CONF_AUTOMATIC_SELF_CALIBRATION, default=True): cv.boolean,
+    cv.Optional(CONF_ALTITUDE_COMPENSATION): cv.All(remove_altitude_suffix,
+                                                    cv.int_range(min=0, max=0xFFFF,
+                                                                 max_included=False)),
 }).extend(cv.polling_component_schema('60s')).extend(i2c.i2c_device_schema(0x61))
 
 
@@ -24,6 +37,10 @@ def to_code(config):
     yield cg.register_component(var, config)
     yield i2c.register_i2c_device(var, config)
 
+    cg.add(var.set_automatic_self_calibration(config[CONF_AUTOMATIC_SELF_CALIBRATION]))
+    if CONF_ALTITUDE_COMPENSATION in config:
+        cg.add(var.set_altitude_compensation(config[CONF_ALTITUDE_COMPENSATION]))
+
     if CONF_CO2 in config:
         sens = yield sensor.new_sensor(config[CONF_CO2])
         cg.add(var.set_co2_sensor(sens))

tests/test1.yaml

@@ -584,6 +584,8 @@ sensor:
       name: "Living Room Humidity 9"
     address: 0x61
     update_interval: 15s
+    automatic_self_calibration: true
+    altitude_compensation: 10m
   - platform: sgp30
     eco2:
       name: "Workshop eCO2"