add detection range

esphome/components/mhz19/mhz19.cpp

@@ -11,6 +11,9 @@ static const uint8_t MHZ19_COMMAND_GET_PPM[] = {0xFF, 0x01, 0x86, 0x00, 0x00, 0x
 static const uint8_t MHZ19_COMMAND_ABC_ENABLE[] = {0xFF, 0x01, 0x79, 0xA0, 0x00, 0x00, 0x00, 0x00};
 static const uint8_t MHZ19_COMMAND_ABC_DISABLE[] = {0xFF, 0x01, 0x79, 0x00, 0x00, 0x00, 0x00, 0x00};
 static const uint8_t MHZ19_COMMAND_CALIBRATE_ZERO[] = {0xFF, 0x01, 0x87, 0x00, 0x00, 0x00, 0x00, 0x00};
+static const uint8_t MHZ19_COMMAND_DETECTION_RANGE_0_2000PPM[] = {0xFF, 0x01, 0x99, 0x00, 0x00, 0x00, 0x07, 0xD0};
+static const uint8_t MHZ19_COMMAND_DETECTION_RANGE_0_5000PPM[] = {0xFF, 0x01, 0x99, 0x00, 0x00, 0x00, 0x13, 0x88};
+static const uint8_t MHZ19_COMMAND_DETECTION_RANGE_0_10000PPM[] = {0xFF, 0x01, 0x99, 0x00, 0x00, 0x00, 0x27, 0x10};
 
 uint8_t mhz19_checksum(const uint8_t *command) {
   uint8_t sum = 0;
@@ -26,6 +29,24 @@ void MHZ19Component::setup() {
   } else if (this->abc_boot_logic_ == MHZ19_ABC_DISABLED) {
     this->abc_disable();
   }
+
+  switch (this->detection_range_) {
+    case MHZ19_DETECTION_RANGE_DEFAULT:
+      ESP_LOGD(TAG, "Using previously set detection range (no change)");
+      break;
+    case MHZ19_DETECTION_RANGE_0_2000PPM:
+      ESP_LOGD(TAG, "Setting detection range to 0 to 2000ppm");
+      this->mhz19_write_command_(MHZ19_COMMAND_DETECTION_RANGE_0_2000PPM, nullptr);
+      break;
+    case MHZ19_DETECTION_RANGE_0_5000PPM:
+      ESP_LOGD(TAG, "Setting detection range to 0 to 5000ppm");
+      this->mhz19_write_command_(MHZ19_COMMAND_DETECTION_RANGE_0_5000PPM, nullptr);
+      break;
+    case MHZ19_DETECTION_RANGE_0_10000PPM:
+      ESP_LOGD(TAG, "Setting detection range to 0 to 10000ppm");
+      this->mhz19_write_command_(MHZ19_COMMAND_DETECTION_RANGE_0_10000PPM, nullptr);
+      break;
+  }
 }
 
 void MHZ19Component::update() {
@@ -97,7 +118,9 @@ bool MHZ19Component::mhz19_write_command_(const uint8_t *command, uint8_t *respo
 
   return this->read_array(response, MHZ19_RESPONSE_LENGTH);
 }
+
 float MHZ19Component::get_setup_priority() const { return setup_priority::DATA; }
+
 void MHZ19Component::dump_config() {
   ESP_LOGCONFIG(TAG, "MH-Z19:");
   LOG_SENSOR("  ", "CO2", this->co2_sensor_);
@@ -111,6 +134,23 @@ void MHZ19Component::dump_config() {
   }
 
   ESP_LOGCONFIG(TAG, "  Warmup seconds: %ds", this->warmup_seconds_);
+
+  const char *range_str;
+  switch (this->detection_range_) {
+    case MHZ19_DETECTION_RANGE_DEFAULT:
+      range_str = "default";
+      break;
+    case MHZ19_DETECTION_RANGE_0_2000PPM:
+      range_str = "0 to 2000ppm";
+      break;
+    case MHZ19_DETECTION_RANGE_0_5000PPM:
+      range_str = "0 to 5000ppm";
+      break;
+    case MHZ19_DETECTION_RANGE_0_10000PPM:
+      range_str = "0 to 10000ppm";
+      break;
+  }
+  ESP_LOGCONFIG(TAG, "  Detection range: %s", range_str);
 }
 
 }  // namespace mhz19

esphome/components/mhz19/mhz19.h

@@ -8,7 +8,18 @@
 namespace esphome {
 namespace mhz19 {
 
-enum MHZ19ABCLogic { MHZ19_ABC_NONE = 0, MHZ19_ABC_ENABLED, MHZ19_ABC_DISABLED };
+enum MHZ19ABCLogic {
+  MHZ19_ABC_NONE = 0,
+  MHZ19_ABC_ENABLED,
+  MHZ19_ABC_DISABLED,
+};
+
+enum MHZ19DetectionRange {
+  MHZ19_DETECTION_RANGE_DEFAULT = 0,
+  MHZ19_DETECTION_RANGE_0_2000PPM,
+  MHZ19_DETECTION_RANGE_0_5000PPM,
+  MHZ19_DETECTION_RANGE_0_10000PPM,
+};
 
 class MHZ19Component : public PollingComponent, public uart::UARTDevice {
  public:
@@ -27,13 +38,18 @@ class MHZ19Component : public PollingComponent, public uart::UARTDevice {
   void set_abc_enabled(bool abc_enabled) { abc_boot_logic_ = abc_enabled ? MHZ19_ABC_ENABLED : MHZ19_ABC_DISABLED; }
   void set_warmup_seconds(uint32_t seconds) { warmup_seconds_ = seconds; }
 
+  void set_detection_range(MHZ19DetectionRange detection_range) { detection_range_ = detection_range; }
+
  protected:
   bool mhz19_write_command_(const uint8_t *command, uint8_t *response);
 
   sensor::Sensor *temperature_sensor_{nullptr};
   sensor::Sensor *co2_sensor_{nullptr};
   MHZ19ABCLogic abc_boot_logic_{MHZ19_ABC_NONE};
+
   uint32_t warmup_seconds_;
+
+  MHZ19DetectionRange detection_range_{MHZ19_DETECTION_RANGE_DEFAULT};
 };
 
 template<typename... Ts> class MHZ19CalibrateZeroAction : public Action<Ts...> {

esphome/components/mhz19/sensor.py

@@ -19,6 +19,7 @@ DEPENDENCIES = ["uart"]
 
 CONF_AUTOMATIC_BASELINE_CALIBRATION = "automatic_baseline_calibration"
 CONF_WARMUP_TIME = "warmup_time"
+CONF_DETECTION_RANGE = "detection_range"
 
 mhz19_ns = cg.esphome_ns.namespace("mhz19")
 MHZ19Component = mhz19_ns.class_("MHZ19Component", cg.PollingComponent, uart.UARTDevice)
@@ -49,6 +50,10 @@ CONFIG_SCHEMA = (
             cv.Optional(
                 CONF_WARMUP_TIME, default="75s"
             ): cv.positive_time_period_seconds,
+            cv.Optional(CONF_DETECTION_RANGE): cv.All(
+                cv.float_with_unit("parts per million", "(ppm)"),
+                cv.one_of(2000, 5000, 10000, int=True),
+            ),
         }
     )
     .extend(cv.polling_component_schema("60s"))
@@ -74,6 +79,9 @@ async def to_code(config):
 
     cg.add(var.set_warmup_seconds(config[CONF_WARMUP_TIME]))
 
+    if CONF_DETECTION_RANGE in config:
+        cg.add(var.set_detection_range(config[CONF_DETECTION_RANGE]))
+
 
 CALIBRATION_ACTION_SCHEMA = maybe_simple_id(
     {