Save and get function local storage measurements

src/AgValue.cpp

@@ -2,6 +2,7 @@
 #include "AgConfigure.h"
 #include "AirGradient.h"
 #include "App/AppDef.h"
+#include "SPIFFS.h"
 
 #define json_prop_pmFirmware     "firmware"
 #define json_prop_pm01Ae "pm01"
@@ -1065,4 +1066,61 @@ JSONVar Measurements::buildPMS(AirGradient &ag, int ch, bool allCh, bool withTem
   return pms;
 }
 
-void Measurements::setDebug(bool debug) { _debug = debug; }
+void Measurements::setDebug(bool debug) { _debug = debug; }
+
+void Measurements::saveLocalStorage(AirGradient &ag) {
+  File file;
+  if (!SPIFFS.exists(FILE_PATH)) {
+    file = SPIFFS.open(FILE_PATH, FILE_APPEND, true);
+    file.println("pm0.3 count,pm1,pm2.5,pm10,temp,rhum,co2,tvoc,nox"); // header
+  } else {
+    file = SPIFFS.open(FILE_PATH, FILE_APPEND, false);
+  }
+
+  if (!file) {
+    Serial.println("Failed local storage file path");
+    return;
+  }
+
+  // Save new measurements
+  file.printf("%.2f,%.2f,%.2f,%.2f,%.2f,%.2f,%d,%d,%d\n", ag.round2(_pm_03_pc[0].update.avg),
+              ag.round2(_pm_01[0].update.avg), ag.round2(_pm_25[0].update.avg),
+              ag.round2(_pm_10[0].update.avg), ag.round2(_temperature[0].update.avg),
+              ag.round2(_humidity[0].update.avg), (int)round(_co2.update.avg),
+              (int)round(_tvoc.update.avg), (int)round(_nox.update.avg));
+
+  Serial.println("Success save measurements to local storage");
+}
+
+char *Measurements::getLocalStorage() {
+  char *buf = new char[1024];
+  if (buf == nullptr) {
+    Serial.println("NEW getLocal buffer failed");
+    return nullptr;
+  }
+  memset(buf, 0, 1024);
+
+  // TODO: Buffer based on file size
+  bool success = false;
+  File file = SPIFFS.open(FILE_PATH);
+  if (file && !file.isDirectory()) {
+    if (file.readBytes(buf, file.size()) != file.size()) {
+      Serial.println("Reading measurements file: failed - size not match");
+    } else {
+      Serial.println("Reading measurements file: success");
+      success = true;
+    }
+    file.close();
+  } else {
+    SPIFFS.format();
+  }
+
+  if (!success) {
+    Serial.println("Reading measurements file failed");
+    delete buf;
+    return nullptr;
+  }
+
+  // NOTE: Don't forget to free
+  return buf;
+}

src/AgValue.h

@@ -142,6 +142,9 @@ public:
   String toString(bool localServer, AgFirmwareMode fwMode, int rssi, AirGradient &ag,
                   Configuration &config);
 
+  void saveLocalStorage(AirGradient &ag);
+  char *getLocalStorage();
+
   /**
    * Set to true if want to debug every update value
    */
@@ -173,6 +176,7 @@ private:
   IntegerValue _pm_10_pc[2]; // particle count 10
 
   bool _debug = false;
+  const char *FILE_PATH = "/measurement.csv"; // Local storage file path
 
   /**
    * @brief Get PMS5003 firmware version string