diff --git a/data/index.html b/data/index.html
index 9a5d46d..5311aa6 100644
--- a/data/index.html
+++ b/data/index.html
@@ -62,6 +62,10 @@ <h2 id="large-modal-header"></h2>
 			<p>Communication problem between ESP and STM</p>
 		</div>
 
+		<div id="param-success-bar" class="param-success-bar">
+			<p id="param-success-bar-text"></p>
+		</div>
+
 		<!-- 'Add CAN Mapping' modal -->
 		<div id="can-mapping-modal-overlay" class="modal-overlay">
 			<div id="can-mapping-modal-container" class="can-mapping-modal-container">
@@ -91,7 +95,7 @@ <h3 class="underline">New CAN Mapping</h3>
 						<td>Set the ID of the CAN frame to send/receive</td>
 					</tr>
 					<tr>
-						<td>Offset</td>
+						<td>Position</td>
 						<td><input type="number" step="1" min="0" max="63" id="canpos"></td>
 						<td>Specify the position (offset) within the frame to place (transmit) or find (receive) this value</td>
 					</tr>
@@ -105,6 +109,11 @@ <h3 class="underline">New CAN Mapping</h3>
 						<td><input type="number" step="1" min="1" max="100" id="cangain"></td>
 						<td>Specify a gain to scale the value up or down</td>
 					</tr>
+					<tr>
+						<td>Offset</td>
+						<td><input type="number" step="1" min="-128" max="127" id="canoffset"></td>
+						<td>Specify an offset to add to the value</td>
+					</tr>
 				</table>
 				<button onclick="ui.canMapping();">
 					<!-- /icon-check-circle.png -->
@@ -151,22 +160,15 @@ <h3 class="underline">New CAN Mapping</h3>
 					<img class="navimg" src="data:image/png;base64,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"><p class="navbar-text">SUPPORT</p></a>
 			</div>
 
-			<!-- spinner div -->
-			<div id="spinner-div" class="control">
-				<img style="vertical-align:middle" src="ajax-loader.gif"><p> refreshing...</p>
-			</div>
-
 			<!-- auto reload toggle -->
 			<div id="auto-reload-toggle-div" class="control small-screen-hide">
 				<label class="switch">
 					<input id="auto-reload-checkbox" type="checkbox" onclick="ui.setAutoReload(this.checked);"><span class="slider round"></span>
 				</label><p style="display: inline-block;">Auto reload</p>
 			</div>
-			<!-- beta features toggle -->
-			<div id="beta-features-toggle-div" onclick="ui.toggleBetaFeaturesVisibility();" class="control small-screen-hide">
-				<label class="switch">
-					<input id="beta-features-checkbox" type="checkbox"><span class="slider round"></span>
-				</label><p style="display: inline-block;">Beta features</p>
+			<!-- spinner div -->
+			<div id="spinner-div" class="control">
+				<img style="vertical-align:middle" src="ajax-loader.gif"><p> refreshing...</p>
 			</div>
 
 			<div id="version" class="small-screen-hide"></div>
@@ -256,7 +258,7 @@ <h3>OpenInverter Board Firmware</h3>
 						<p>To install a new firmware on your OpenInverter board click on the 'Install firmware from file' button on the right. Use the stm32_sine.bin file to install the sine firmware or use the stm32_foc.bin file to install the FOC firmware. You can find information about the latest available releases, including download links, on the OpenInverter forum <a href="https://openinverter.org/forum/viewforum.php?f=7&sid=cdb63cfa1d2f7ab493e7079fc13a8e65">here</a>.</p>
 
 						<h3>Web Interface Firmware</h3>
-						<p>The ESP8266 firmware can be upgraded with platformio via OTA i.e. directly via wifi without programming cable, see <a href="https://openinverter.org/forum/viewtopic.php?p=60907#p60907">forum</a>.<br>
+						<p>The ESP32 firmware can be upgraded with platformio via OTA i.e. directly via wifi without programming cable, see <a href="https://openinverter.org/forum/viewtopic.php?p=60907#p60907">forum</a>.
 You can also program with a cable, see <a href="https://openinverter.org/forum/viewtopic.php?f=5&t=8">here</a> for more details.</p>
 
 						<h3>Web Interface Application</h3>
@@ -493,9 +495,10 @@ <h3 class="underline">Existing CAN Mappings</h3>
 								<th>Spot Value</th>
 								<th>Transmit or Receive</th>
 								<th>ID</th>
-								<th>Offset</th>
+								<th>Position</th>
 								<th>Length</th>
 								<th>Gain</th>
+								<th>Offset</th>
 								<th>Delete Mapping</th>
 							</tr>
 						</table>
diff --git a/data/inverter.js b/data/inverter.js
index 521eaaf..79fa8c3 100644
--- a/data/inverter.js
+++ b/data/inverter.js
@@ -92,6 +92,23 @@ var inverter = {
 		{
 			if (replyFunc) replyFunc(this.responseText);
 		}
+		xmlhttp.onreadystatechange = function() {
+			if (xmlhttp.readyState === XMLHttpRequest.DONE) {
+				console.log(req + ": " + xmlhttp.status);
+				if (xmlhttp.status != 200) {
+					paramsCache.failedFetchCount += 1;
+					if ( paramsCache.failedFetchCount >= 2 && typeof ui !== 'undefined'){
+						ui.showCommunicationErrorBar();
+					}
+				}
+				else {
+					paramsCache.failedFetchCount = 0;
+				}
+				if ( paramsCache.failedFetchCount < 2 && typeof ui !== 'undefined') {
+					ui.hideCommunicationErrorBar();
+				}
+			}
+		}
 
 		if (repeat)
 			req += "&repeat=" + repeat;
@@ -107,8 +124,7 @@ var inverter = {
 
 		inverter.sendCmd(cmd, function(reply) {
 			var params = {};
-			try
-			{
+			try {
 				params = JSON.parse(reply);
 
 				for (var name in params)
@@ -119,19 +135,8 @@ var inverter = {
 					if (name == "version")
 						inverter.firmwareVersion = parseFloat(param.value);
 				}
-				paramsCache.failedFetchCount = 0;
-			}
-			catch(ex)
-			{
-        paramsCache.failedFetchCount += 1;
-        if ( paramsCache.failedFetchCount >= 2 ){
-          ui.showCommunicationErrorBar();
-        }
-			}
-			if ( paramsCache.failedFetchCount < 2 )
-			{
-				ui.hideCommunicationErrorBar();
-			}
+			} catch(ex) { console.error('Failed to parse params:', ex); }
+
 			paramsCache.setData(params);
 			if (replyFunc) replyFunc(params);
 		});
@@ -157,10 +162,7 @@ var inverter = {
 			replyFunc(values);
 		};
 
-		if (inverter.firmwareVersion < 3.53 || items.length > 10)
-			inverter.sendCmd("get " + items.join(','), process, repeat);
-		else
-			inverter.sendCmd("stream " + repeat + " " + items.join(','), process);
+		inverter.sendCmd("stream " + repeat + " " + items.join(','), process);
 	},
 
 
diff --git a/data/style.css b/data/style.css
index 9f9f0ef..b2d9717 100644
--- a/data/style.css
+++ b/data/style.css
@@ -656,3 +656,22 @@ input:checked + .slider:before {
 .communication-error-bar p {
     text-align: center;
 }
+
+.param-success-bar {
+    display: none;
+    padding: 15px;
+    background-color: #4caf50;
+    color: white;
+    z-index: 100;
+    margin: 0 auto;
+    position: relative;
+    width: 30%;
+    top: 0px;
+    clear: left;
+    height: 20px;
+    border-radius: 0px 0px 20px 20px;
+}
+
+.param-success-bar p {
+    text-align: center;
+}
diff --git a/data/ui.js b/data/ui.js
index 07d647a..90b1960 100644
--- a/data/ui.js
+++ b/data/ui.js
@@ -32,13 +32,15 @@ var ui = {
 	// Status of visibility of parameter categories. E.g. Motor, Inverter. true = visible, false = not visible.
 	categoryVisible: {},
 
+	navbarIsBig: true,
+
 	shrinkNavbar: function() {
-		document.getElementById("navbar").style.width = "80px";
+		document.getElementById("navbar").style.width = "60px";
 		var cw = document.getElementById("content-wrapper");
-		cw.style.left = "80px";
-		cw.style.width = "calc(100% - 80px)";
+		cw.style.left = "60px";
+		cw.style.width = "calc(100% - 60px)";
 		var logo = document.getElementById("logo");
-		logo.style.width = "80px";
+		logo.style.width = "60px";
 		logo.style.height = "50px";
 		// buttons
 		var buttons = document.getElementsByClassName("buttonimg");
@@ -131,10 +133,24 @@ var ui = {
 			}
 		});
 
+		// Pause auto-refresh while the user is editing a parameter field, resume when done
+		var paramsTable = document.getElementById('params');
+		paramsTable.addEventListener('focusin', function(event) {
+			if (event.target.tagName === 'INPUT' || event.target.tagName === 'SELECT') {
+				clearInterval(ui.autoRefreshHandle);
+			}
+		});
+		paramsTable.addEventListener('focusout', function(event) {
+			if (event.target.tagName === 'INPUT' || event.target.tagName === 'SELECT') {
+				if (document.getElementById('auto-reload-checkbox').checked) {
+					ui.autoRefreshHandle = setInterval(ui.refresh, 2000);
+				}
+			}
+		});
+
 		ui.updateTables();
 		plot.generateChart();
 		ui.parameterDatabaseCheckForUpdates();
-		ui.populateSpotValueDropDown();
 		ui.populateExistingCanMappingTable();
 		wifi.populateWiFiTab();
 		ui.populateFileList();
@@ -229,7 +245,7 @@ var ui = {
 						if (param.enums[param.value])
 						{
 
-						    valInput = '<SELECT onchange="ui.showParamUpdateModal(\'' + name + '\', this.value)">';
+						    valInput = '<SELECT onchange="ui.sendParameterUpdate(\'' + name + '\', this.value)">';
 
 						    for (var idx in param.enums)
 						    {
@@ -253,8 +269,9 @@ var ui = {
 					}
 					else
 					{
+						var step = Number.isInteger(param.value) ? 1 : 0.04;
 						valInput = '<INPUT type="number" min="' + param.minimum + '" max="' + param.maximum +
-							'" step="0.05" value="' + param.value + '" onchange="ui.showParamUpdateModal(\'' + name + '\', this.value)"/>';
+							'" step="' + step + '" value="' + param.value + '" onchange="ui.sendParameterUpdate(\'' + name + '\', this.value)"/>';
 					}
 
 					if (param.i !== undefined)
@@ -295,6 +312,7 @@ var ui = {
 				}
 			}
       ui.populateVersion();
+      ui.populateSpotValueDropDown();
 			document.getElementById("paramDownload").href = "data:text/json;charset=utf-8," + encodeURIComponent(JSON.stringify(params, null, 2));
 			document.getElementById("spinner-div").style.visibility = "hidden";
 		});
@@ -354,7 +372,7 @@ var ui = {
       // run the poll function every 2 seconds
       if (enable) {
         autoReloadCheckbox.checked = true;
-        ui.autoRefreshHandle = setInterval(ui.refresh, 3000);
+        ui.autoRefreshHandle = setInterval(ui.refresh, 2000);
       }
       else {
         autoReloadCheckbox.checked = false;
@@ -372,6 +390,16 @@ var ui = {
 		document.getElementById('communication-error-bar').style.display = 'none';
 	},
 
+	/** @brief Show green success bar with a message, then auto-hide after a delay */
+	showParamSuccessBar: function(message) {
+		document.getElementById('param-success-bar-text').textContent = message;
+		document.getElementById('param-success-bar').style.display = 'block';
+		clearTimeout(ui.paramSuccessBarTimer);
+		ui.paramSuccessBarTimer = setTimeout(function() {
+			document.getElementById('param-success-bar').style.display = 'none';
+		}, 2000);
+	},
+
 	/**
 	 * ~~~ DASHBOARD ~~~
 	 */
@@ -383,11 +411,6 @@ var ui = {
 		var statusDiv = document.getElementById('top-left');
 
 		var status = paramsCache.get('status');
-
-		if ( status == null ){
-			return;
-		}
-
 		var lasterr = paramsCache.get('lasterr');
 		var udc = paramsCache.get('udc');
 		var tmphs = paramsCache.get('tmphs');
@@ -398,50 +421,60 @@ var ui = {
 		var tbl = document.createElement('table');
 		var tbody = document.createElement('tbody');
 		// status
-		var tr = document.createElement('tr');
-		var td = document.createElement('td');
-		td.appendChild(document.createTextNode('Status'));
-		tr.appendChild(td);
-		td = document.createElement('td');
-		td.appendChild(document.createTextNode(status));
-		tr.appendChild(td);
-		tbody.appendChild(tr);
+		if (status != null) {
+			var tr = document.createElement('tr');
+			var td = document.createElement('td');
+			td.appendChild(document.createTextNode('Status'));
+			tr.appendChild(td);
+			td = document.createElement('td');
+			td.appendChild(document.createTextNode(status));
+			tr.appendChild(td);
+			tbody.appendChild(tr);
+		}
 		// opmode
-		tr = document.createElement('tr');
-	    td = document.createElement('td');
-		td.appendChild(document.createTextNode('Opmode'));
-		tr.appendChild(td);
-		td = document.createElement('td');
-		td.appendChild(document.createTextNode(opmode));
-		tr.appendChild(td);
-		tbody.appendChild(tr);
+		if (opmode != null) {
+			var tr = document.createElement('tr');
+			var td = document.createElement('td');
+			td.appendChild(document.createTextNode('Opmode'));
+			tr.appendChild(td);
+			td = document.createElement('td');
+			td.appendChild(document.createTextNode(opmode));
+			tr.appendChild(td);
+			tbody.appendChild(tr);
+		}
 		// lasterr
-		tr = document.createElement('tr');
-		td = document.createElement('td');
-		td.appendChild(document.createTextNode('Last error'));
-		tr.appendChild(td);
-		td = document.createElement('td');
-		td.appendChild(document.createTextNode(lasterr));
-		tr.appendChild(td);
-		tbody.appendChild(tr);
+		if (lasterr != null) {
+			var tr = document.createElement('tr');
+			var td = document.createElement('td');
+			td.appendChild(document.createTextNode('Last error'));
+			tr.appendChild(td);
+			td = document.createElement('td');
+			td.appendChild(document.createTextNode(lasterr));
+			tr.appendChild(td);
+			tbody.appendChild(tr);
+		}
 		// udc
-		tr = document.createElement('tr');
-		td = document.createElement('td');
-		td.appendChild(document.createTextNode('Battery voltage (udc)'));
-		tr.appendChild(td);
-		td = document.createElement('td');
-		td.appendChild(document.createTextNode(udc));
-		tr.appendChild(td);
-		tbody.appendChild(tr);
+		if (udc != null) {
+			var tr = document.createElement('tr');
+			var td = document.createElement('td');
+			td.appendChild(document.createTextNode('Battery voltage (udc)'));
+			tr.appendChild(td);
+			td = document.createElement('td');
+			td.appendChild(document.createTextNode(udc));
+			tr.appendChild(td);
+			tbody.appendChild(tr);
+		}
 		// tmphs
-		tr = document.createElement('tr');
-		td = document.createElement('td');
-		td.appendChild(document.createTextNode('Inverter temperature'));
-		tr.appendChild(td);
-		td = document.createElement('td');
-		td.appendChild(document.createTextNode(tmphs));
-		tr.appendChild(td);
-		tbody.appendChild(tr);
+		if (tmphs != null) {
+			var tr = document.createElement('tr');
+			var td = document.createElement('td');
+			td.appendChild(document.createTextNode('Inverter temperature'));
+			tr.appendChild(td);
+			td = document.createElement('td');
+			td.appendChild(document.createTextNode(tmphs));
+			tr.appendChild(td);
+			tbody.appendChild(tr);
+		}
 
 
 		tbl.appendChild(tbody);
@@ -562,13 +595,10 @@ var ui = {
 
 		xmlhttp.onload = function()
 		{
-			// Show popup reporting upload completion
-			modal.emptyModal('small');
-			modal.appendToModal('small', 'File upload complete');
-			modal.showModal('small');
 			// Refresh the list of files on the 'files' page
 			ui.populateFileList();
-			setTimeout(function() { modal.hideModal('small') }, 2000);
+			// Show non-intrusive success notification
+			ui.showParamSuccessBar('File upload complete');
 		}
 
 		xmlhttp.open("POST", "/edit");
@@ -787,6 +817,16 @@ var ui = {
      * ~~~ PARAMETERS ~~~
      */
 
+    /** @brief Send parameter update to inverter and show result in success bar */
+    sendParameterUpdate: function(param, value)
+    {
+    	var c = 'set ' + param + ' ' + value;
+    	inverter.sendCmd(c, function(reply)
+		{
+			ui.showParamSuccessBar(param + ' = ' + value + ' \u2014 ' + reply.trim());
+		});
+    },
+
     /** @brief Show modal box with the result of parameter update */
     showParamUpdateModal: async function(param, value)
     {
@@ -1268,6 +1308,9 @@ var ui = {
 		        	// cangain
 					var canGainCell = tr.insertCell(-1);
 		        	canGainCell.innerHTML = param.cangain;
+		        	// canoffset value (value offset to add)
+					var canOffsetValCell = tr.insertCell(-1);
+		        	canOffsetValCell.innerHTML = typeof param.canoffset_value !== 'undefined' ? param.canoffset_value : 0;
 		        	// delete button
 					var canDeleteCell = tr.insertCell(-1);
 					var cmd = "inverter.canMapping('del', '" + name + "');ui.populateExistingCanMappingTable();";
@@ -1281,6 +1324,8 @@ var ui = {
 	populateSpotValueDropDown: function()
 	{
 		var select = document.getElementById("add-can-mapping-spot-value-drop-down");
+		// Clear existing options before repopulating to avoid duplicates on refresh
+		while (select.options.length > 0) select.remove(0);
 		inverter.getParamList(function(values) {
 			for (var name in values) {
 				var param = values[name];
diff --git a/esp32-web-interface.ino b/esp32-web-interface.ino
index 3c2c398..26767fc 100644
--- a/esp32-web-interface.ino
+++ b/esp32-web-interface.ino
@@ -243,7 +243,8 @@ bool handleFileRead(String path){
     if(SPIFFS.exists(pathWithGz))
       path += ".gz";
     File file = SPIFFS.open(path, "r");
-    size_t sent = server.streamFile(file, contentType);
+    server.sendHeader("Cache-Control", "max-age=86400");
+    server.streamFile(file, contentType);
     file.close();
     return true;
   }
@@ -256,7 +257,7 @@ bool handleFileRead(String path){
 
     if (SD_MMC.exists(path)) {
       File file = SD_MMC.open(path, "r");
-      size_t sent = server.streamFile(file, contentType);
+      server.streamFile(file, contentType);
       file.close();
     return true;
     }
@@ -796,7 +797,6 @@ void setup(void){
   });
 
   server.begin();
-  server.client().setNoDelay(1);
 
   MDNS.addService("http", "tcp", 80);
 }
@@ -821,7 +821,7 @@ void binaryLoggingStart()
       uart_set_baudrate(INVERTER_PORT, 2250000);
       uart_write_bytes(INVERTER_PORT, "\n", 1);
       delay(1);
-      uart_write_bytes(INVERTER_PORT, "binarylogging 0", strnlen("binarylogging 0", UART_MESSBUF_SIZE));
+      uart_write_bytes(INVERTER_PORT, "binarylogging 0", strlen("binarylogging 0"));
       uart_write_bytes(INVERTER_PORT, "\n", 1);
       uart_wait_tx_done(INVERTER_PORT, UART_TIMEOUT);
       uart_set_baudrate(INVERTER_PORT, 115200);
@@ -835,7 +835,7 @@ void binaryLoggingStop()
 {
   uart_write_bytes(INVERTER_PORT, "\n", 1);
   delay(1);
-  uart_write_bytes(INVERTER_PORT, "binarylogging 0", strnlen("binarylogging 0", UART_MESSBUF_SIZE));
+  uart_write_bytes(INVERTER_PORT, "binarylogging 0", strlen("binarylogging 0"));
   uart_write_bytes(INVERTER_PORT, "\n", 1);
   uart_wait_tx_done(INVERTER_PORT, UART_TIMEOUT);
   uart_set_baudrate(INVERTER_PORT, 115200);