Added warning for problematic setpoint transition values.

locales/en/messages.json

@@ -1258,6 +1258,9 @@
     "pidTuningDtermSetpointHelp": {
         "message": "This parameter determines the stick accelerating effect within derivative component.<br> Value of 0 equals to old Measuemenent method where D only tracks gyro, while value of 1 equals to old Error method with equal gyro and stick tracking ratio.<br> Lower value equals to slower/smoother stick response, while higher value provides more stick acceleration response.<br> Note that RC interpolation is recommended to be enabled with higher values to prevent control kicks making noise."
     },
+    "pidTuningDtermSetpointTransitionWarning": {
+        "message": "<span class=\"message-negative\"><strong>Warning:<\/strong> The use of a D Setpoint transition between 0 and 0.1 is highly discouraged. Doing so will lead to a 'jump' around the midpoint of the sticks.<\/span>"
+    },
     "pidTuningProportional": {
         "message": "Proportional"
     },

src/css/main.css

@@ -111,11 +111,11 @@ input[type="number"]::-webkit-inner-spin-button {
 }
 
 .message-positive {
-    color: #ffbb00;
+    color: #ffbb00 !important;
 }
 
 .message-negative {
-    color: red;
+    color: red !important;
 }
 
 .headerbar {

src/js/tabs/pid_tuning.js

@@ -685,10 +685,23 @@ TABS.pid_tuning.initialize = function (callback) {
 
             var dtermTransitionNumberElement = $('input[name="dtermSetpointTransition-number"]');
             var dtermTransitionRangeElement = $('input[name="dtermSetpointTransition-range"]');
+            var dtermTransitionWarningElement = $('#pid-tuning .dtermSetpointTransitionWarning');
+
+            function checkUpdateDtermTransitionWarning(value) {
+                if (value > 0 && value < 0.1) {
+                    dtermTransitionWarningElement.show();
+                } else {
+                    dtermTransitionWarningElement.hide();
+                }
+            }
+            checkUpdateDtermTransitionWarning(dtermTransitionNumberElement.val());
+
             dtermTransitionNumberElement.change(function () {
+                checkUpdateDtermTransitionWarning($(this).val());
                 dtermTransitionRangeElement.val($(this).val());
             });
             dtermTransitionRangeElement.change(function () {
+                checkUpdateDtermTransitionWarning($(this).val());
                 dtermTransitionNumberElement.val($(this).val());
             });
 

src/tabs/pid_tuning.html

@@ -314,10 +314,16 @@
                                         <span i18n="pidTuningDtermSetpointTransition"></span>
                                         </label>
                                         <div class="helpicon cf_tip" i18n_title="pidTuningDtermSetpointTransitionHelp"></div>
-                                </div>
+                                    </div>
-                            </td>
+                                 </td>
                             </tr>
-                            <td style="height:30px;"><input type="checkbox" id="vbatpidcompensation" class="toggle" /></td>
+                            <tr class="dtermSetpointTransitionWarning">
+                                <td colspan="3">
+                                    <span i18n="pidTuningDtermSetpointTransitionWarning"></span>
+                                </td>
+                            </tr>
+                            <tr>
+                                <td style="height:30px;"><input type="checkbox" id="vbatpidcompensation" class="toggle" /></td>
                                 <td colspan="2">
                                     <div>
                                         <label for="vbatpidcompensation">
@@ -326,6 +332,7 @@
                                         <div class="helpicon cf_tip" i18n_title="pidTuningVbatPidCompensationHelp"></div>
                                     </div>
                                 </td>
+                            </tr>
                         </table>
                     </div>