Handle pm correction algorithm from ag server config

src/AgConfigure.cpp

@@ -22,6 +22,18 @@ const char *LED_BAR_MODE_NAMES[] = {
     [LedBarModeCO2] = "co2",
 };
 
+const char *PM_CORRECTION_ALGORITHM_NAMES[] = {
+    [Unknown] = "-", // This is only to pass "non-trivial designated initializers" error
+    [None] = "none",
+    [EPA_2021] = "epa_2021",
+    [SLR_PMS5003_20220802] = "slr_PMS5003_20220802",
+    [SLR_PMS5003_20220803] = "slr_PMS5003_20220803",
+    [SLR_PMS5003_20220824] = "slr_PMS5003_20220824",
+    [SLR_PMS5003_20231030] = "slr_PMS5003_20231030",
+    [SLR_PMS5003_20231218] = "slr_PMS5003_20231218",
+    [SLR_PMS5003_20240104] = "slr_PMS5003_20240104",
+};
+
 #define JSON_PROP_NAME(name) jprop_##name
 #define JSON_PROP_DEF(name) const char *JSON_PROP_NAME(name) = #name
 
@@ -87,6 +99,96 @@ String Configuration::getLedBarModeName(LedBarMode mode) {
   return String("unknown");
 }
 
+PMCorrectionAlgorithm Configuration::matchPmAlgorithm(String algorithm) {
+  // Loop through all algorithm names in the PM_CORRECTION_ALGORITHM_NAMES array
+  // If the input string matches an algorithm name, return the corresponding enum value
+  // Else return Unknown
+  for (int idx = 0;
+       idx < sizeof(PM_CORRECTION_ALGORITHM_NAMES) / sizeof(PM_CORRECTION_ALGORITHM_NAMES[0]);
+       idx++) {
+    if (algorithm == PM_CORRECTION_ALGORITHM_NAMES[idx]) {
+      return (PMCorrectionAlgorithm)idx;
+    }
+  }
+
+  return Unknown;
+}
+
+bool Configuration::parsePmCorrection(JSONVar &json) {
+  if (!json.hasOwnProperty("corrections")) {
+    // TODO: need to response message?
+    Serial.println("corrections not found");
+    return false;
+  }
+
+  JSONVar corrections = json["corrections"];
+  if (!corrections.hasOwnProperty("pm02")) {
+    Serial.println("pm02 not found");
+    return false;
+  }
+
+  JSONVar pm02 = corrections["pm02"];
+  if (!pm02.hasOwnProperty("correctionAlgorithm")) {
+    Serial.println("correctionAlgorithm not found");
+    return false;
+  }
+
+  // Check algorithm
+  const char *algorithm = (const char *)pm02["correctionAlgorithm"];
+  PMCorrectionAlgorithm algo = matchPmAlgorithm(algorithm);
+  if (algo == Unknown) {
+    Serial.println("Unknown algorithm");
+    return false;
+  }
+  Serial.printf("Correction algorithm: %s\n", algorithm);
+
+  // If algo is None or EPA_2021, no need to check slr
+  // But first check if pmCorrection different from algo
+  if (algo == None || algo == EPA_2021) {
+    if (pmCorrection.algorithm != algo) {
+      pmCorrection.algorithm = algo;
+      pmCorrection.changed = true;
+      Serial.println("PM2.5 correction updated");
+      return true;
+    }
+
+    return false;
+  }
+
+  // Check if pm02 has slr object
+  if (!pm02.hasOwnProperty("slr")) {
+    Serial.println("slr not found");
+    return false;
+  }
+
+  JSONVar slr = pm02["slr"];
+
+  // Validate required slr properties exist
+  if (!slr.hasOwnProperty("intercept") || !slr.hasOwnProperty("scalingFactor") ||
+      !slr.hasOwnProperty("useEpa2021")) {
+    Serial.println("Missing required slr properties");
+    return false;
+  }
+
+  // Compare with current pmCorrection
+  if (pmCorrection.algorithm == algo && pmCorrection.intercept == (double)slr["intercept"] &&
+      pmCorrection.scalingFactor == (double)slr["scalingFactor"] &&
+      pmCorrection.useEPA == (bool)slr["useEpa2021"]) {
+    return false; // No changes needed
+  }
+
+  // Update pmCorrection with new values
+  pmCorrection.algorithm = algo;
+  pmCorrection.intercept = (double)slr["intercept"];
+  pmCorrection.scalingFactor = (double)slr["scalingFactor"];
+  pmCorrection.useEPA = (bool)slr["useEpa2021"];
+  pmCorrection.changed = true;
+
+  // Correction values were updated
+  Serial.println("PM2.5 correction updated");
+  return true;
+}
+
 /**
  * @brief Save configure to device storage (EEPROM)
  *
@@ -171,6 +273,13 @@ void Configuration::defaultConfig(void) {
   jconfig[jprop_offlineMode] = jprop_offlineMode_default;
   jconfig[jprop_monitorDisplayCompensatedValues] = jprop_monitorDisplayCompensatedValues_default;
 
+  // PM2.5 correction
+  pmCorrection.algorithm = None;
+  pmCorrection.changed = false;
+  pmCorrection.intercept = -1;
+  pmCorrection.scalingFactor = -1;
+  pmCorrection.useEPA = false;
+
   saveConfig();
 }
 
@@ -667,6 +776,11 @@ bool Configuration::parse(String data, bool isLocal) {
     }
   }
 
+  // Corrections
+  if (parsePmCorrection(root)) {
+    changed = true;
+  }
+
   if (changed) {
     udpated = true;
     saveConfig();

src/AgConfigure.h

@@ -5,8 +5,18 @@
 #include "Main/PrintLog.h"
 #include "AirGradient.h"
 #include <Arduino.h>
+#include "Libraries/Arduino_JSON/src/Arduino_JSON.h"
 
 class Configuration : public PrintLog {
+public:
+  struct PMCorrection {
+    PMCorrectionAlgorithm algorithm;
+    int intercept;
+    int scalingFactor;
+    bool useEPA; // EPA 2021
+    bool changed;
+  };
+
 private:
   bool co2CalibrationRequested;
   bool ledBarTestRequested;
@@ -19,10 +29,13 @@ private:
   String otaNewFirmwareVersion;
   bool _offlineMode = false;
   bool _ledBarModeChanged = false;
+  PMCorrection pmCorrection;
 
   AirGradient* ag;
 
   String getLedBarModeName(LedBarMode mode);
+  PMCorrectionAlgorithm matchPmAlgorithm(String algorithm);
+  bool parsePmCorrection(JSONVar &json);
   void saveConfig(void);
   void loadConfig(void);
   void defaultConfig(void);

src/App/AppDef.h

@@ -94,6 +94,18 @@ enum ConfigurationControl {
   ConfigurationControlBoth
 };
 
+enum PMCorrectionAlgorithm {
+  Unknown, // Unknown algorithm
+  None,    // No PM correction
+  EPA_2021,
+  SLR_PMS5003_20220802,
+  SLR_PMS5003_20220803,
+  SLR_PMS5003_20220824,
+  SLR_PMS5003_20231030,
+  SLR_PMS5003_20231218,
+  SLR_PMS5003_20240104,
+};
+
 enum AgFirmwareMode {
   FW_MODE_I_9PSL, /** ONE_INDOOR */
   FW_MODE_O_1PST, /** PMS5003T, S8 and SGP41 */