From 541d8ce451826aefd21c1f0fd23b31ea3784658a Mon Sep 17 00:00:00 2001
From: Andreas Schiermeier <andreas@schiermeier.name>
Date: Tue, 1 Nov 2022 23:30:46 +0100
Subject: [PATCH] feat: SCD30 support pressure compensation updates

---
 esphome/components/scd30/scd30.cpp | 30 ++++++++++++++++++++++++------
 esphome/components/scd30/scd30.h   |  2 ++
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/esphome/components/scd30/scd30.cpp b/esphome/components/scd30/scd30.cpp
index 3eeca23800..b7d7b4ae89 100644
--- a/esphome/components/scd30/scd30.cpp
+++ b/esphome/components/scd30/scd30.cpp
@@ -102,15 +102,17 @@ void SCD30Component::setup() {
 #endif
 
   /// Sensor initialization
-  if (!this->write_command(SCD30_CMD_START_CONTINUOUS_MEASUREMENTS, this->ambient_pressure_compensation_)) {
-    ESP_LOGE(TAG, "Sensor SCD30 error starting continuous measurements.");
-    this->error_code_ = MEASUREMENT_INIT_FAILED;
-    this->mark_failed();
-    return;
-  }
+  restart_continuous_measurements_();
 
   // check each 500ms if data is ready, and read it in that case
   this->set_interval("status-check", 500, [this]() {
+    // remove millibar from comparison to avoid frequent updates +/- 10 millibar doesn't matter
+    if (this->current_ambient_pressure_compensation_ / 10 != this->ambient_pressure_compensation_ / 10) {
+      ESP_LOGD(TAG, "ambient pressure compensation triggered; restarting measurements");
+      this->restart_continuous_measurements_();
+      return;
+    }
+
     if (this->is_data_ready_())
       this->update();
   });
@@ -229,5 +231,21 @@ uint16_t SCD30Component::get_forced_calibration_reference() {
   return forced_calibration_reference;
 }
 
+void SCD30Component::restart_continuous_measurements_() {
+  if (!this->write_command(SCD30_CMD_STOP_MEASUREMENTS, this->ambient_pressure_compensation_)) {
+    ESP_LOGE(TAG, "Sensor SCD30 error stopping continuous measurements.");
+    this->error_code_ = MEASUREMENT_INIT_FAILED;
+    this->mark_failed();
+    return;
+  }
+  if (!this->write_command(SCD30_CMD_START_CONTINUOUS_MEASUREMENTS, this->ambient_pressure_compensation_)) {
+    ESP_LOGE(TAG, "Sensor SCD30 error starting continuous measurements.");
+    this->error_code_ = MEASUREMENT_INIT_FAILED;
+    this->mark_failed();
+    return;
+  }
+  this->current_ambient_pressure_compensation_ = this->ambient_pressure_compensation_;
+}
+
 }  // namespace scd30
 }  // namespace esphome
diff --git a/esphome/components/scd30/scd30.h b/esphome/components/scd30/scd30.h
index 40f075e673..8373fd56df 100644
--- a/esphome/components/scd30/scd30.h
+++ b/esphome/components/scd30/scd30.h
@@ -30,6 +30,7 @@ class SCD30Component : public Component, public sensirion_common::SensirionI2CDe
 
  protected:
   bool is_data_ready_();
+  void restart_continuous_measurements_();
 
   enum ErrorCode {
     COMMUNICATION_FAILED,
@@ -41,6 +42,7 @@ class SCD30Component : public Component, public sensirion_common::SensirionI2CDe
   bool enable_asc_{true};
   uint16_t altitude_compensation_{0xFFFF};
   uint16_t ambient_pressure_compensation_{0x0000};
+  uint16_t current_ambient_pressure_compensation_{0x0000};
   float temperature_offset_{0.0};
   uint16_t update_interval_{0xFFFF};