Added model memory

CG_scale.ino

@@ -4,7 +4,7 @@
                       (c) 2019 by M. Lehmann
   ------------------------------------------------------------------
 */
-#define CGSCALE_VERSION "1.0.58"
+#define CGSCALE_VERSION "1.0.62"
 /*
 
   ******************************************************************
@@ -58,6 +58,7 @@
 #include <ESP8266WiFi.h>
 #include <WiFiClient.h>
 #include <ESP8266WebServer.h>
+#include <ArduinoJson.h>
 #endif
 
 // load settings
@@ -76,6 +77,7 @@ HX711_ADC LoadCell_3(PIN_LOADCELL3_DOUT, PIN_LOADCELL3_PD_SCK);
 #if defined(ESP8266)
 ESP8266WebServer server(80);
 IPAddress apIP(ip[0], ip[1], ip[2], ip[3]);
+File fsUploadFile;              // a File object to temporarily store the received file
 #endif
 
 // serial menu
@@ -119,7 +121,8 @@ enum {
   P_PASSWORD_STA =                      P_SSID_STA + MAX_SSID_PW_LENGHT + 1,
   P_SSID_AP =                           P_PASSWORD_STA + MAX_SSID_PW_LENGHT + 1,
   P_PASSWORD_AP =                       P_SSID_AP + MAX_SSID_PW_LENGHT + 1,
-  EEPROM_SIZE =                         P_PASSWORD_AP + MAX_SSID_PW_LENGHT + 1
+  P_MODELNAME =                         P_PASSWORD_AP + MAX_SSID_PW_LENGHT + 1,
+  EEPROM_SIZE =                         P_MODELNAME + MAX_MODELNAME_LENGHT + 1
 #endif
 };
 
@@ -195,42 +198,40 @@ bool updateMenu = true;
 int menuPage = 0;
 String errMsg[5] = "";
 int errMsgCnt = 0;
+#if defined(ESP8266)
+char curModelName[MAX_MODELNAME_LENGHT + 1] = "";
+#endif
 
 
 // Restart CPU
 void(* resetCPU) (void) = 0;
 
 
-// reset to factory defaults
-void resetDefault() {
-  // reset eeprom
-  for (int i = 0; i < EEPROM_SIZE; i++) {
-    EEPROM.write(i, 0xFF);
-  }
-  Serial.end();
-#if defined(ESP8266)
-  EEPROM.commit();
-#endif
-  resetCPU();
-}
-
-
 // save calibration factor
 void saveCalFactor1() {
   LoadCell_1.setCalFactor(calFactorLoadcell1);
   EEPROM.put(P_LOADCELL1_CALIBRATION_FACTOR, calFactorLoadcell1);
+#if defined(ESP8266)
+  EEPROM.commit();
+#endif
 }
 
 
 void saveCalFactor2() {
   LoadCell_2.setCalFactor(calFactorLoadcell2);
   EEPROM.put(P_LOADCELL2_CALIBRATION_FACTOR, calFactorLoadcell2);
+#if defined(ESP8266)
+  EEPROM.commit();
+#endif
 }
 
 
 void saveCalFactor3() {
   LoadCell_3.setCalFactor(calFactorLoadcell3);
   EEPROM.put(P_LOADCELL3_CALIBRATION_FACTOR, calFactorLoadcell3);
+#if defined(ESP8266)
+  EEPROM.commit();
+#endif
 }
 
 
@@ -269,6 +270,7 @@ void setup() {
   Serial.begin(9600);
 
 #if defined(ESP8266)
+  // init filesystem
   SPIFFS.begin();
   EEPROM.begin(EEPROM_SIZE);
 #endif
@@ -339,11 +341,21 @@ void setup() {
     EEPROM.get(P_PASSWORD_AP, password_AP);
   }
 
+  if (EEPROM.read(P_MODELNAME) != 0xFF) {
+    EEPROM.get(P_MODELNAME, curModelName);
+  }
+
+  // load current model
+  if (!openModelJson(curModelName)) {
+    curModelName[0] = '\0';
+  }
+
   // Start by connecting to a WiFi network
   WiFi.mode(WIFI_STA);
   WiFi.begin(ssid_STA, password_STA);
 
   long timeoutWiFi = millis();
+
 #endif
 
   // init OLED display
@@ -379,7 +391,7 @@ void setup() {
   while ((loadcell_1_rdy + loadcell_2_rdy + loadcell_3_rdy) < 3) {
     loadcell_1_rdy = LoadCell_1.startMultiple(STABILISINGTIME);
     loadcell_2_rdy = LoadCell_2.startMultiple(STABILISINGTIME);
-    if (nLoadcells > 2) {
+    if (nLoadcells == 3) {
       loadcell_3_rdy = LoadCell_3.startMultiple(STABILISINGTIME);
     } else {
       loadcell_3_rdy = 1;
@@ -465,8 +477,15 @@ void setup() {
   server.on("/getParameter", getParameter);
   server.on("/getWiFiNetworks", getWiFiNetworks);
   server.on("/saveParameter", saveParameter);
-  server.on("/resetDefault", resetDefault);
   server.on("/autoCalibrate", autoCalibrate);
+  server.on("/saveModel", saveModel);
+  server.on("/openModel", openModel);
+  server.on("/deleteModel", deleteModel);
+
+  // When the client upload file
+  server.on("/models.html", HTTP_POST, []() {
+    server.send(200, "text/plain", "");
+  }, handleFileUpload);
 
   // If the client requests any URI
   server.onNotFound([]() {
@@ -607,36 +626,54 @@ void loop() {
           case MENU_LOADCELLS:
             nLoadcells = Serial.parseInt();
             EEPROM.put(P_NUMBER_LOADCELLS, nLoadcells);
+#if defined(ESP8266)
+            EEPROM.commit();
+#endif
             menuPage = 0;
             updateMenu = true;
             break;
           case MENU_DISTANCE_X1:
             distanceX1 = Serial.parseFloat();
             EEPROM.put(P_DISTANCE_X1, distanceX1);
+#if defined(ESP8266)
+            EEPROM.commit();
+#endif
             menuPage = 0;
             updateMenu = true;
             break;
           case MENU_DISTANCE_X2:
             distanceX2 = Serial.parseFloat();
             EEPROM.put(P_DISTANCE_X2, distanceX2);
+#if defined(ESP8266)
+            EEPROM.commit();
+#endif
             menuPage = 0;
             updateMenu = true;
             break;
           case MENU_DISTANCE_X3:
             distanceX3 = Serial.parseFloat();
             EEPROM.put(P_DISTANCE_X3, distanceX3);
+#if defined(ESP8266)
+            EEPROM.commit();
+#endif
             menuPage = 0;
             updateMenu = true;
             break;
           case MENU_REF_WEIGHT:
             refWeight = Serial.parseFloat();
             EEPROM.put(P_REF_WEIGHT, refWeight);
+#if defined(ESP8266)
+            EEPROM.commit();
+#endif
             menuPage = 0;
             updateMenu = true;
             break;
           case MENU_REF_CG:
             refCG = Serial.parseFloat();
             EEPROM.put(P_REF_CG, refCG);
+#if defined(ESP8266)
+            EEPROM.commit();
+#endif
             menuPage = 0;
             updateMenu = true;
             break;
@@ -668,12 +705,18 @@ void loop() {
           case MENU_RESISTOR_R1:
             resistorR1 = Serial.parseFloat();
             EEPROM.put(P_RESISTOR_R1, resistorR1);
+#if defined(ESP8266)
+            EEPROM.commit();
+#endif
             menuPage = 0;
             updateMenu = true;
             break;
           case MENU_RESISTOR_R2:
             resistorR2 = Serial.parseFloat();
             EEPROM.put(P_RESISTOR_R2, resistorR2);
+#if defined(ESP8266)
+            EEPROM.commit();
+#endif
             menuPage = 0;
             updateMenu = true;
             break;
@@ -684,6 +727,9 @@ void loop() {
               enableBatVolt = false;
             }
             EEPROM.put(P_ENABLE_BATVOLT, enableBatVolt);
+#if defined(ESP8266)
+            EEPROM.commit();
+#endif
             menuPage = 0;
             updateMenu = true;
             break;
@@ -694,7 +740,19 @@ void loop() {
             break;
           case MENU_RESET_DEFAULT:
             if (Serial.read() == 'J') {
-              resetDefault();
+              // reset eeprom
+              for (int i = 0; i < EEPROM_SIZE; i++) {
+                EEPROM.write(i, 0xFF);
+              }
+              Serial.end();
+#if defined(ESP8266)
+              EEPROM.commit();
+              // delete json model file
+              if (SPIFFS.exists(MODEL_FILE)) {
+                SPIFFS.remove(MODEL_FILE);
+              }
+#endif
+              resetCPU();
             }
             menuPage = 0;
             updateMenu = true;
@@ -923,7 +981,30 @@ void getRawValue() {
 
 // send parameters to client
 void getParameter() {
+  char buff[8];
   String response = "";
+  float weightTotal_saved = 0;
+  float CG_length_saved = 0;
+  float CG_trans_saved = 0;
+
+  StaticJsonBuffer<JSONBUFFER_SIZE> jsonBuffer;
+  //DynamicJsonBuffer  jsonBuffer(JSONBUFFER_SIZE);
+
+  if (SPIFFS.exists(MODEL_FILE)) {
+    // read json file
+    File f = SPIFFS.open(MODEL_FILE, "r");
+    JsonObject& root = jsonBuffer.parseObject(f);
+    f.close();
+    // check if model exists
+    if (root.success() && root.containsKey(curModelName)) {
+      JsonObject& object = root[curModelName];
+      weightTotal_saved = object["wt"];
+      CG_length_saved = object["cg"];
+      CG_trans_saved = object["cglr"];
+    }
+  }
+
+  // parameter list
   response += nLoadcells;
   response += "&";
   response += distanceX1;
@@ -959,6 +1040,18 @@ void getParameter() {
   response += ssid_AP;
   response += "&";
   response += password_AP;
+  response += "&";
+  response += curModelName;
+  response += "&";
+  dtostrf(weightTotal_saved, 5, 1, buff);
+  response += buff;
+  response += "g&";
+  dtostrf(CG_length_saved, 5, 1, buff);
+  response += buff;
+  response += "mm&";
+  dtostrf(CG_trans_saved, 5, 1, buff);
+  response += buff;
+  response += "mm";
   server.send(200, "text/html", response);
 }
 
@@ -1020,14 +1113,53 @@ void saveParameter() {
   EEPROM.put(P_PASSWORD_AP, password_AP);
   EEPROM.commit();
 
-  server.send(200, "text/html", "ok");
+  // save current model to json
+  saveModelJson(curModelName);
+
+  server.send(200, "text/plain", "saved");
 }
 
 
 // calibrate cg scale
 void autoCalibrate() {
   while (!runAutoCalibrate());
-  server.send(200, "text/html", "ok");
+  server.send(200, "text/plain", "parameters saved");
+}
+
+
+// save new model
+void saveModel() {
+  if (server.hasArg("modelname")) {
+    if (saveModelJson(server.arg("modelname"))) {
+      server.send(200, "text/plain", "saved");
+      return;
+    }
+  }
+  server.send(404, "text/plain", "404: Save model failed !");
+}
+
+
+// open model
+void openModel() {
+  if (server.hasArg("modelname")) {
+    if (openModelJson(server.arg("modelname"))) {
+      server.send(200, "text/plain", "opened");
+      return;
+    }
+  }
+  server.send(404, "text/plain", "404: Open model failed !");
+}
+
+
+// delete model
+void deleteModel() {
+  if (server.hasArg("modelname")) {
+    if (deleteModelJson(server.arg("modelname"))) {
+      server.send(200, "text/plain", "deleted");
+      return;
+    }
+  }
+  server.send(404, "text/plain", "404: Delete model failed !");
 }
 
 
@@ -1046,6 +1178,7 @@ String getContentType(String filename) {
 
 // send file to the client (if it exists)
 bool handleFileRead(String path) {
+
   // If a folder is requested, send the index file
   if (path.endsWith("/")) path += "index.html";
   String contentType = getContentType(path);
@@ -1060,6 +1193,175 @@ bool handleFileRead(String path) {
     file.close();
     return true;
   }
+
   return false;
 }
+
+
+// upload a new file to the SPIFFS
+void handleFileUpload() {
+
+  HTTPUpload& upload = server.upload();
+
+  if (upload.status == UPLOAD_FILE_START) {
+    String filename = upload.filename;
+    if (!filename.startsWith("/")) filename = "/" + filename;
+    if (filename != MODEL_FILE ) server.send(500, "text/plain", "wrong file !");
+    // Open the file for writing in SPIFFS (create if it doesn't exist)
+    fsUploadFile = SPIFFS.open(filename, "w");
+    filename = String();
+  } else if (upload.status == UPLOAD_FILE_WRITE) {
+    // Write the received bytes to the file
+    fsUploadFile.write(upload.buf, upload.currentSize);
+  } else if (upload.status == UPLOAD_FILE_END) {
+    // If the file was successfully created
+    if (fsUploadFile) {
+      fsUploadFile.close();
+      // Redirect the client to the success page
+      server.sendHeader("Location", "/models.html");
+      server.send(303);
+    } else {
+      server.send(500, "text/plain", "500: couldn't create file");
+    }
+  }
+
+}
+
+
+// save model to json file
+bool saveModelJson(String modelName) {
+
+  if (modelName.length() > MAX_MODELNAME_LENGHT) {
+    return false;
+  }
+
+  StaticJsonBuffer<JSONBUFFER_SIZE> jsonBuffer;
+  //DynamicJsonBuffer  jsonBuffer(JSONBUFFER_SIZE);
+
+  if (SPIFFS.exists(MODEL_FILE)) {
+    // read json file
+    File f = SPIFFS.open(MODEL_FILE, "r");
+    JsonObject& root = jsonBuffer.parseObject(f);
+    f.close();
+    if (!root.success()) {
+      return false;
+    }
+    // check if model exists
+    if (root.containsKey(modelName)) {
+      writeModelData(root[modelName]);
+    } else {
+      // otherwise create new
+      writeModelData(root.createNestedObject(modelName));
+    }
+    // write to file
+    if (root.success()) {
+      f = SPIFFS.open(MODEL_FILE, "w");
+      root.printTo(f);
+      f.close();
+    } else {
+      return false;
+    }
+  } else {
+    // creat new json
+    JsonObject& root = jsonBuffer.createObject();
+    writeModelData(root.createNestedObject(modelName));
+    // write to file
+    if (root.success()) {
+      File f = SPIFFS.open(MODEL_FILE, "w");
+      root.printTo(f);
+      f.close();
+    } else {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+
+// read model data from json file
+bool openModelJson(String modelName) {
+
+  StaticJsonBuffer<JSONBUFFER_SIZE> jsonBuffer;
+  //DynamicJsonBuffer  jsonBuffer(JSONBUFFER_SIZE);
+
+  if (SPIFFS.exists(MODEL_FILE)) {
+    // read json file
+    File f = SPIFFS.open(MODEL_FILE, "r");
+    JsonObject& root = jsonBuffer.parseObject(f);
+    f.close();
+    if (!root.success()) {
+      return false;
+    }
+    // check if model exists
+    if (root.containsKey(modelName)) {
+      JsonObject& object = root[modelName];
+      // load parameters from model
+      distanceX1 = object["x1"];
+      distanceX2 = object["x2"];
+      distanceX3 = object["x3"];
+    } else {
+      return false;
+    }
+
+    // save current model name to eeprom
+    modelName.toCharArray(curModelName, MAX_MODELNAME_LENGHT + 1);
+    EEPROM.put(P_MODELNAME, curModelName);
+    EEPROM.commit();
+
+    return true;
+  }
+
+  return false;
+}
+
+
+// delete model from json file
+bool deleteModelJson(String modelName) {
+
+  StaticJsonBuffer<JSONBUFFER_SIZE> jsonBuffer;
+  //DynamicJsonBuffer  jsonBuffer(JSONBUFFER_SIZE);
+
+  if (SPIFFS.exists(MODEL_FILE)) {
+    // read json file
+    File f = SPIFFS.open(MODEL_FILE, "r");
+    JsonObject& root = jsonBuffer.parseObject(f);
+    f.close();
+    if (!root.success()) {
+      return false;
+    }
+    // check if model exists
+    if (root.containsKey(modelName)) {
+      root.remove(modelName);
+    } else {
+      return false;
+    }
+    // if no models in json, kill it
+    if (root.size() == 0) {
+      SPIFFS.remove(MODEL_FILE);
+    } else {
+      // write to file
+      if (root.success()) {
+        File f = SPIFFS.open(MODEL_FILE, "w");
+        root.printTo(f);
+        f.close();
+      } else {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  return false;
+
+}
+
+void writeModelData(JsonObject& object) {
+  object["wt"] = weightTotal;
+  object["cg"] = CG_length;
+  object["cglr"] = CG_trans;
+  object["x1"] = distanceX1;
+  object["x2"] = distanceX2;
+  object["x3"] = distanceX3;
+}
 #endif

data/index.html

@@ -11,6 +11,8 @@
     <script>
         var CG_trans_visible = true;
         var batVolt_visible = true;
+        var curModelName = "";
+        
         function getHead(){
             var request = new XMLHttpRequest();
             request.onreadystatechange = function(){
@@ -34,6 +36,7 @@
                     if(this.responseText != null){
                         var responseString = this.responseText;
                         var value = responseString.split("&");
+                        
                         if(value[0] == "2"){
                             CG_trans_visible = false;
                             document.getElementById("cglrContainer").outerHTML = "";
@@ -42,6 +45,16 @@
                             batVolt_visible = false;
                             document.getElementById("batContainer").outerHTML = "";
                         }
+                        curModelName = value[16];
+                        if (curModelName != "") {
+                            document.getElementById("modelName").innerHTML = curModelName;
+                            document.getElementById("saveButton").classList.remove('disabled');
+                            document.getElementById("weightTotalSaved").innerHTML = value[17];
+                            document.getElementById("CG_lengthSaved").innerHTML = value[18];
+                            if(CG_trans_visible == true){
+                                document.getElementById("CG_transSaved").innerHTML = value[19];
+                            }
+                        }
                     }
                 }
             }
@@ -56,7 +69,7 @@
                         var responseString = this.responseText;
                         var value = responseString.split("&");
                         document.getElementById("weightTotal").innerHTML = value[0];
-                        document.getElementById("CG_length").innerHTML = value[1];
+                        document.getElementById("CG_length").innerHTML = value[1];                        
                         if(CG_trans_visible == true){
                             document.getElementById("CG_trans").innerHTML = value[2];
                         }
@@ -70,55 +83,98 @@
             request.send();
             setTimeout('getValue()', 1000);
         }
+        function saveModel(){
+            if (curModelName != "") {
+                var request = new XMLHttpRequest();
+                request.onreadystatechange = function(){
+                    if(this.readyState == 4 && this.status == 200){
+                        alert(curModelName + " saved");
+                        location.reload();
+                    }else if(this.readyState == 4 && this.status == 404){
+                        alert("Model not saved !");
+                    }
+                }
+                request.open("GET", "saveModel?modelname=" + curModelName, true);
+                request.send();
+            }
+        }
     </script>
 </head>
-<body onload=getValue()>
-    <script>        
-        getHead();
-        getParameter();
-    </script>
+<body>
     <nav class="navbar navbar-dark fixed-top bg-dark">
         <div class="container-fluid">
             <div class="navbar-header">
-                <a class="navbar-brand" href="#"><span id="ssid"></span></a>"
+                <a class="navbar-brand" href="#"><span id="ssid"></span></a>
             </div>
             <ul class="nav navbar-nav navbar-right">
-                <button type="button" onclick="location.href = '/settings.html'" class="btn btn-danger">
-                    <img src="settings.png" alt="" style="width:auto;height:30px">
-                </button>
+                <form class="form-inline">            
+                    <button type="button" onclick="location.href = '/models.html'" class="btn btn-primary navbar-btn mx-2">
+                        <img src="airplane.png" alt="" style="width:auto;height:30px">
+                        <span id="modelName"></span>
+                    </button>
+                    <button type="button" onclick="location.href = '/settings.html'" class="btn btn-danger navbar-btn">
+                        <img src="settings.png" alt="" style="width:auto;height:30px">
+                    </button>
+                </form>
             </ul>
         </div>
     </nav>
-    <br><br><br>
-    <main role="main" class="container">
+    <main role="main" class="container" style="margin-top:100px">
         <div class="jumbotron">
             <div class="container" id="wgContainer">
                 <div class="row mt-3">
                     <div class="col-xs-6"><img src="weight.png" class="pull-left mr-4" alt="Weight" style="width:auto;height:50px"></div>
-                    <div class="col-xs-6 d-flex align-items-center"><font size="6"><span id="weightTotal">-</span></font></div>
+                    <div class="col-xs-6 d-flex align-items-center">
+                        <font size="6">
+                            <span class="ml-4 mr-4" id="weightTotal">-</span>
+                        </font>
+                        <small class="form-text text-muted" id="weightTotalSaved"></small>
+                    </div>
                 </div>
             </div>
             <div class="container" id="cgContainer">
                 <div class="row mt-3">
                     <div class="col-xs-6"><img src="cg.png" class="pull-left mr-4" alt="CG" style="width:auto;height:50px"></div>
-                    <div class="col-xs-6 d-flex align-items-center"><font size="6"><span id="CG_length">-</span></font></div>
+                    <div class="col-xs-6 d-flex align-items-center">
+                        <font size="6">
+                            <span class="ml-4 mr-4" id="CG_length">-</span>
+                        </font>
+                        <small class="form-text text-muted" id="CG_lengthSaved"></small>
+                    </div>
                 </div>
             </div> 
             <div class="container" id="cglrContainer">
                 <div class="row mt-3">
                     <div class="col-xs-6"><img src="cglr.png" class="pull-left mr-4" alt="CG left/right" style="width:auto;height:50px"></div>
-                    <div class="col-xs-6 d-flex align-items-center"><font size="6"><span id="CG_trans">-</span></font></div>
+                    <div class="col-xs-6 d-flex align-items-center">
+                        <font size="6">
+                            <span class="ml-4 mr-4" id="CG_trans">-</span>
+                        </font>
+                        <small class="form-text text-muted" id="CG_transSaved"></small>
+                    </div>
                 </div>
             </div> 
             <div class="container" id="batContainer">
                 <div class="row mt-3">
                     <div class="col-xs-6"><img src="battery.png" class="pull-left mr-4" alt="Battery" style="width:auto;height:50px"></div>
-                    <div class="col-xs-6 d-flex align-items-center"><font size="6"><span id="batVolt">-</span></font></div>
+                    <div class="col-xs-6 d-flex align-items-center">
+                        <font size="6">
+                            <span class="ml-4 mr-4" id="batVolt">-</span>
+                        </font>
+                    </div>
                 </div>
             </div>
             <div class="container"><font size="6"><span id="errMsg"></span></font></div>
         </div>
+        <div class="text-center">
+            <button class="btn btn-success btn-lg disabled" onclick="saveModel()" id="saveButton">Save</button>
+        </div>
     </main>
     <p><font size="2"><center>(c) 2019 M. Lehmann - Version: <span id="cgscaleVersion">0.0</span></center></font></p>
+    <script>        
+        getHead();
+        getParameter();
+        getValue();
+    </script>
 </body>
 </html>

data/models.html

@@ -0,0 +1,199 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
+    <meta name="description" content="">
+    <meta name="author" content="M. Lehmann">
+    <title>CG scale by M. Lehmann</title>
+    <link href="/bootstrap.min.css" rel="stylesheet">
+    <script src="/bootstrap.min.js"></script>
+    <script src="/jquery-3.3.1.slim.min.js"></script>
+    <script>
+        var CG_trans_visible = true;
+        var curModelName = "";
+        
+        function getHead(){
+            var request = new XMLHttpRequest();
+            request.onreadystatechange = function(){
+                if(this.readyState == 4 && this.status == 200){
+                    if(this.responseText != null){
+                        var responseString = this.responseText;
+                        var value = responseString.split("&");
+                        document.getElementById("ssid").innerHTML = value[0];
+                        document.getElementById("cgscaleVersion").innerHTML = value[2];
+                    }
+                }
+            }
+            request.open("GET", "getHead", true);
+            request.send();
+        }
+        function getParameter(){
+            var request = new XMLHttpRequest();
+            request.onreadystatechange = function(){
+                if(this.readyState == 4 && this.status == 200){
+                    if(this.responseText != null){
+                        var responseString = this.responseText;
+                        var value = responseString.split("&");
+                        if(value[0] == "2"){
+                            CG_trans_visible = false;
+                        }
+                        curModelName = value[16];
+                    }
+                }
+            }
+            request.open("GET", "getParameter", true);
+            request.send();
+        }
+        function getModels(){
+            var request = new XMLHttpRequest();
+            request.onreadystatechange = function(){
+                if(this.readyState == 4 && this.status == 200){
+                    var root = JSON.parse(this.responseText);
+                    var table = document.getElementById("models");
+                    if(CG_trans_visible == false){
+                        document.getElementById("cgLRrow").outerHTML = "";
+                        
+                    }
+                    for (name in root) {
+                        var row = table.insertRow();
+                        var cellName = row.insertCell(0);
+                        var cellWeight = row.insertCell(1);
+                        var cellCG = row.insertCell(2);
+                        cellName.innerHTML = name;
+                        cellWeight.innerHTML = root[name].wt;
+                        cellCG.innerHTML = root[name].cg;
+                        if(CG_trans_visible == true){
+                            var cellcglr = row.insertCell(3);
+                            var cellButton = row.insertCell(4);
+                            cellcglr.innerHTML = root[name].cglr;
+                        }else{
+                            var cellButton = row.insertCell(3);
+                        }
+                        if(name != curModelName){
+                            var htmlbutton = '<div class="btn-group"><button type="button" onclick="openModel(\'';
+                            htmlbutton += name;
+                            htmlbutton += '\')" class="btn btn-success">Open</button><button type="button" onclick="deleteModel(\'';
+                            htmlbutton += name;
+                            htmlbutton += '\')" class="btn btn-danger">Delete</button></div>';
+                            cellButton.innerHTML = htmlbutton;
+                        }else{
+                            row.setAttribute("class", "table-active");
+                        }
+                    }
+                }else if(this.readyState == 4 && this.status == 404){
+                    document.getElementById("backup").outerHTML = "";
+                    //alert("No models saved !");
+                }
+            }
+            request.open("GET", "models.json", true);
+            request.send();
+        }
+        function saveModel(){
+            var modelname = prompt("Please enter new model name:");
+            if (modelname != "") {
+                var request = new XMLHttpRequest();
+                request.onreadystatechange = function(){
+                    if(this.readyState == 4 && this.status == 200){
+                        location.reload();
+                    }else if(this.readyState == 4 && this.status == 404){
+                        alert("Model not saved !");
+                    }
+                }
+                request.open("GET", "saveModel?modelname=" + modelname, true);
+                request.send();
+            }
+        }
+        function openModel(modelname){
+            if (modelname != "") {
+                var request = new XMLHttpRequest();
+                request.onreadystatechange = function(){
+                    if(this.readyState == 4 && this.status == 200){
+                        location.reload();
+                    }else if(this.readyState == 4 && this.status == 404){
+                        alert("Model not open !");
+                    }
+                }
+                request.open("GET", "openModel?modelname=" + modelname, true);
+                request.send();
+            }
+        }
+        function deleteModel(modelname){
+            if (modelname != "" && confirm("Do you want to delete: " + modelname + "?")){
+                var request = new XMLHttpRequest();
+                request.onreadystatechange = function(){
+                    if(this.readyState == 4 && this.status == 200){
+                        location.reload();
+                    }else if(this.readyState == 4 && this.status == 404){
+                        alert("Model not deleted !");
+                    }
+                }
+                request.open("GET", "deleteModel?modelname=" + modelname, true);
+                request.send();
+            }
+        }
+        function download(file)
+        {
+         window.location=file;
+        }
+        
+    </script>
+</head>
+<body>
+    <nav class="navbar navbar-dark fixed-top bg-dark">
+        <div class="container-fluid">
+            <div class="navbar-header">
+                <a class="navbar-brand" href="#"><span id="ssid"></span></a>
+            </div>
+            <ul class="nav navbar-nav navbar-right">
+                <form class="form-inline">            
+                    <button type="button" onclick="location.href = '/'" class="btn btn-danger navbar-btn mx-2">
+                        <img src="home.png" alt="" style="width:auto;height:30px">
+                    </button>
+                    <button type="button" onclick="location.href = '/settings.html'" class="btn btn-danger navbar-btn">
+                        <img src="settings.png" alt="" style="width:auto;height:30px">
+                    </button>
+                </form>
+            </ul>
+        </div>
+    </nav>
+    <main role="main" class="container" style="margin-top:100px">
+        <table class="table" id="models">
+            <thead>
+                <tr>
+                    <th scope="col">Name</th>
+                    <th scope="col">Weight [g]</th>
+                    <th scope="col">CG [mm]</th>
+                    <th scope="col" id="cgLRrow">CG left-right [mm]</th>
+                    <th scope="col"></th>
+                </tr>
+            </thead>
+        </table>
+        <button type="button" onclick="saveModel()" class="btn btn-primary btn-lg">New model</button>
+        <form method="post" enctype="multipart/form-data">
+            <div class="custom-file mt-5">
+                <input type="file" class="custom-file-input" id="customFile" name="filename">
+                <label class="custom-file-label" for="customFile">Restore file...</label>
+            </div>
+            
+            <script>
+                $('.custom-file-input').on('change', function() { 
+                    let fileName = $(this).val().split('\\').pop(); 
+                    $(this).next('.custom-file-label').addClass("selected").html(fileName); 
+                });
+            </script>
+
+            <div class="mt-4">
+                <a class="btn btn-outline-success btn-lg" id="backup" role="button" href="models.json" download="models.json">Backup</a>
+                <button type="submit" class="btn btn-outline-danger btn-lg">Restore</button>
+            </div>
+        </form> 
+    </main>
+    <p><font size="2"><center>(c) 2019 M. Lehmann - Version: <span id="cgscaleVersion">0.0</span></center></font></p>
+    <script>
+        getHead();
+        getParameter();
+        getModels();
+    </script>    
+</body>
+</html>

data/settings.html

@@ -10,6 +10,7 @@
     <script src="/bootstrap.min.js"></script>
     <script>
         var CG_trans_visible = true;
+        
         function getHead(){
             var request = new XMLHttpRequest();
             request.onreadystatechange = function(){
@@ -18,7 +19,6 @@
                         var responseString = this.responseText;
                         var value = responseString.split("&");
                         document.getElementById("ssid").innerHTML = value[0];
-                        //document.getElementById("errMsg").innerHTML = value[1];
                         document.getElementById("cgscaleVersion").innerHTML = value[2];
                     }
                 }
@@ -68,6 +68,7 @@
                         setValue("password_STA", value[13]);
                         setValue("ssid_AP", value[14]);
                         setValue("password_AP", value[15]);
+                        document.getElementById("modelName").innerHTML = value[16];
                         if(value[0] == "2"){
                             CG_trans_visible = false;
                             document.getElementById("lc3_div").outerHTML = "";
@@ -117,52 +118,31 @@
             data += "&ssid_AP=" + document.getElementById("ssid_AP").value;
             data += "&password_AP=" + document.getElementById("password_AP").value;
             var request = new XMLHttpRequest();
-            request.open("GET", "saveParameter" + data, true);
             request.onreadystatechange = function(){
                 if(this.readyState == 4 && this.status == 200){
-                    if(this.responseText == "ok"){
-                        alert("Parameters saved");
-                        getParameter();
-                    }else{
-                        alert("Save parameter failed !");
-                    }
+                    alert("Parameters saved");
+                    getParameter();
+                }else if(this.readyState == 4 && this.status == 404){
+                    alert("Save parameter failed !");
                 }
             }
+            request.open("GET", "saveParameter" + data, true);
             request.send();
         }
         function autoCalibrate(){
             alert("Please put the reference weight on the scale.");
             var request = new XMLHttpRequest();
-            request.open("GET", "autoCalibrate", true);
             request.onreadystatechange = function(){
                 if(this.readyState == 4 && this.status == 200){
-                    if(this.responseText == "ok"){
-                        alert("Calibration successful");
-                        getParameter();
-                    }else{
-                        alert("Calibration failed !");
-                    }
+                    alert("Calibration successful");
+                    getParameter();
+                }else if(this.readyState == 4 && this.status == 404){
+                    alert("Calibration failed !");
                 }
             }
+            request.open("GET", "autoCalibrate", true);
             request.send();
         }
-        function resetDefault(){
-            if (confirm("Reset to factory defaults ?")) {
-                var request = new XMLHttpRequest();
-                request.open("GET", "resetDefault", true);
-                request.onreadystatechange = function(){
-                    if(this.readyState == 4 && this.status == 200){
-                        if(this.responseText == "ok"){
-                            alert("Reset to factory defaults successful");
-                            getParameter();
-                        }else{
-                            alert("Reset to factory defaults failed !");
-                        }
-                    }
-                }
-                request.send();
-            }
-        }
         function setValue(id, value)
         {    
             var element = document.getElementById(id);
@@ -174,24 +154,26 @@
         }
     </script>
 </head>
-<body onload=getRawValue()>
-    <script>
-        getHead();
-        getWiFiNetworks();
-        getParameter();
-    </script>
+<body>
     <nav class="navbar navbar-dark fixed-top bg-dark">
         <div class="container-fluid">
             <div class="navbar-header">
-                <a class="navbar-brand" href="#"><span id="ssid"></span></a>"
+                <a class="navbar-brand" href="#"><span id="ssid"></span></a>
             </div>
             <ul class="nav navbar-nav navbar-right">
-                <button type="button" onclick="location.href = '/'" class="btn btn-danger">Home</button>
+                <form class="form-inline">            
+                    <button type="button" onclick="location.href = '/models.html'" class="btn btn-primary navbar-btn mx-2">
+                        <img src="airplane.png" alt="" style="width:auto;height:30px">
+                        <span id="modelName"></span>
+                    </button>
+                    <button type="button" onclick="location.href = '/'" class="btn btn-danger navbar-btn">
+                        <img src="home.png" alt="" style="width:auto;height:30px">
+                    </button>
+                </form>
             </ul>
         </div>
     </nav>
-    <br><br><br>
-    <main role="main" class="container">
+    <main role="main" class="container" style="margin-top:100px">
         <h3>WiFi settings</h3>
         <div class="form-group">
             <label>Home WiFi name (SSID):</label>
@@ -271,9 +253,8 @@
             </select>
         </div>
         <br><br>
-        <button class="btn btn-success btn-lg" onclick="saveParameter()">save</button>
-        <button class="btn btn-primary btn-lg" onclick="autoCalibrate()">auto calibrate</button>
-        <button class="btn btn-danger btn-lg" onclick="resetDefault()">reset</button>
+        <button class="btn btn-success btn-lg" onclick="saveParameter()">Save</button>
+        <button class="btn btn-primary btn-lg" onclick="autoCalibrate()">Auto calibrate</button>
         <img src="CG_scale_mechanics.png" class="pull-left mr-4" alt="mechanics" style="width:100%">
         <font size="4">
             <div>
@@ -287,9 +268,13 @@
             </div>
         </font> 
         <br><br>
-        <!--<p><font size="4"><center>Lc1: <span id="lc1">-</span> Lc2: <span id="lc2">-</span><div id="lc3_div"> Lc3: <span id="lc3">-</span></div></center></font></p>-->
     </main>
-    <!--<div class="container"><font size="6"><span id="errMsg">-</span></font></div>-->
     <p><font size="2"><center>(c) 2019 M. Lehmann - Version: <span id="cgscaleVersion">0.0</span></center></font></p>
+    <script>
+        getHead();
+        getWiFiNetworks();
+        getParameter();
+        getRawValue();
+    </script>
 </body>
 </html>

settings_ESP8266.h

@@ -137,3 +137,10 @@ U8G2_SH1106_128X64_NONAME_1_HW_I2C oledDisplay(U8G2_R0, /* reset=*/ U8X8_PIN_NON
 #define SSID_AP                     "CG scale"
 #define PASSWORD_AP                 ""
 const char ip[4] =                  {1,1,1,1};    // default IP address
+
+
+// **** Model memory settings ****
+
+#define MAX_MODELNAME_LENGHT        15               // max chars 
+#define MODEL_FILE                  "/models.json"   // file to store models
+#define JSONBUFFER_SIZE             20000            // max file size in bytes