Add pingpong mode with speed, time, and randomness settings

- Add pingpong oscillation mode that alternates motor direction
- Settings: base speed (10-100%), time before return (0.5-10s)
- Randomness controls for both speed (0-50%) and time (0-50%)
- Web UI with sliders and start/stop buttons
- API endpoints: /pingpong/start and /pingpong/stop
- Real-time status polling shows pingpong active state

include/motor.h

@@ -21,6 +21,15 @@ public:
     
     // Callback for stall events
     void setStallCallback(void (*callback)(float current));
+    
+    // Pingpong mode
+    void startPingpong(int speed, int timeMs, int speedRandomPercent, int timeRandomPercent);
+    void stopPingpong();
+    bool isPingpongActive();
+    int getPingpongSpeed();
+    int getPingpongTime();
+    int getPingpongSpeedRandom();
+    int getPingpongTimeRandom();
 
 private:
     int _speed = 0;
@@ -31,9 +40,22 @@ private:
     unsigned long _stallStartTime = 0;
     void (*_stallCallback)(float current) = nullptr;
     
+    // Pingpong state
+    bool _pingpongActive = false;
+    int _pingpongBaseSpeed = 50;
+    int _pingpongBaseTime = 2000;
+    int _pingpongSpeedRandomPercent = 0;
+    int _pingpongTimeRandomPercent = 0;
+    int _pingpongCurrentSpeed = 50;
+    int _pingpongCurrentTime = 2000;
+    unsigned long _pingpongLastSwitch = 0;
+    int _pingpongDirection = 1;
+    
     void applyMotorState();
     float readCurrentSense(int pin);
     void checkStall();
+    void updatePingpong();
+    int applyRandomness(int baseValue, int randomPercent);
 };
 
 extern MotorController motor;

src/motor.cpp

@@ -78,6 +78,9 @@ void MotorController::update() {
     // Check for stall condition
     checkStall();
 #endif
+    
+    // Update pingpong mode
+    updatePingpong();
 }
 
 int MotorController::getSpeed() {
@@ -154,6 +157,89 @@ float MotorController::readCurrentSense(int pin) {
 #endif
 }
 
+// Pingpong mode implementation
+void MotorController::startPingpong(int speed, int timeMs, int speedRandomPercent, int timeRandomPercent) {
+    _pingpongBaseSpeed = constrain(speed, 0, 100);
+    _pingpongBaseTime = constrain(timeMs, 100, 30000);
+    _pingpongSpeedRandomPercent = constrain(speedRandomPercent, 0, 100);
+    _pingpongTimeRandomPercent = constrain(timeRandomPercent, 0, 100);
+    
+    _pingpongDirection = 1;
+    _pingpongCurrentSpeed = applyRandomness(_pingpongBaseSpeed, _pingpongSpeedRandomPercent);
+    _pingpongCurrentTime = applyRandomness(_pingpongBaseTime, _pingpongTimeRandomPercent);
+    _pingpongLastSwitch = millis();
+    _pingpongActive = true;
+    
+    // Apply initial state
+    _speed = _pingpongCurrentSpeed;
+    _direction = _pingpongDirection;
+    applyMotorState();
+    
+    Serial.printf("Pingpong started: speed=%d%% (base=%d, rand=%d%%), time=%dms (base=%d, rand=%d%%)\n",
+                  _pingpongCurrentSpeed, _pingpongBaseSpeed, _pingpongSpeedRandomPercent,
+                  _pingpongCurrentTime, _pingpongBaseTime, _pingpongTimeRandomPercent);
+}
+
+void MotorController::stopPingpong() {
+    _pingpongActive = false;
+    stop();
+    Serial.println("Pingpong stopped");
+}
+
+bool MotorController::isPingpongActive() {
+    return _pingpongActive;
+}
+
+int MotorController::getPingpongSpeed() {
+    return _pingpongBaseSpeed;
+}
+
+int MotorController::getPingpongTime() {
+    return _pingpongBaseTime;
+}
+
+int MotorController::getPingpongSpeedRandom() {
+    return _pingpongSpeedRandomPercent;
+}
+
+int MotorController::getPingpongTimeRandom() {
+    return _pingpongTimeRandomPercent;
+}
+
+void MotorController::updatePingpong() {
+    if (!_pingpongActive) return;
+    
+    unsigned long now = millis();
+    if ((now - _pingpongLastSwitch) >= (unsigned long)_pingpongCurrentTime) {
+        // Time to switch direction
+        _pingpongDirection = -_pingpongDirection;
+        
+        // Apply randomness for next cycle
+        _pingpongCurrentSpeed = applyRandomness(_pingpongBaseSpeed, _pingpongSpeedRandomPercent);
+        _pingpongCurrentTime = applyRandomness(_pingpongBaseTime, _pingpongTimeRandomPercent);
+        _pingpongLastSwitch = now;
+        
+        // Apply new state
+        _speed = _pingpongCurrentSpeed;
+        _direction = _pingpongDirection;
+        applyMotorState();
+        
+        Serial.printf("Pingpong switch: dir=%d, speed=%d%%, next_time=%dms\n",
+                      _pingpongDirection, _pingpongCurrentSpeed, _pingpongCurrentTime);
+    }
+}
+
+int MotorController::applyRandomness(int baseValue, int randomPercent) {
+    if (randomPercent == 0) return baseValue;
+    
+    int maxVariation = (baseValue * randomPercent) / 100;
+    int variation = random(-maxVariation, maxVariation + 1);
+    int result = baseValue + variation;
+    
+    // Ensure result stays positive and reasonable
+    return max(1, result);
+}
+
 void MotorController::checkStall() {
 #if CURRENT_SENSING_ENABLED
     // Only check stall when motor should be running

src/webserver.cpp

@@ -14,20 +14,21 @@ const char index_html[] PROGMEM = R"rawliteral(
     <title>Motor Control</title>
     <style>
         * { box-sizing: border-box; }
-        body { 
-            font-family: Arial, sans-serif; 
-            background: #1a1a2e; 
-            color: #eee; 
-            margin: 0; 
+        body {
+            font-family: Arial, sans-serif;
+            background: #1a1a2e;
+            color: #eee;
+            margin: 0;
             padding: 20px;
             min-height: 100vh;
         }
-        .container { 
-            max-width: 400px; 
-            margin: 0 auto; 
+        .container {
+            max-width: 400px;
+            margin: 0 auto;
             text-align: center;
         }
         h1 { color: #00d9ff; margin-bottom: 30px; }
+        h2 { color: #00d9ff; margin: 20px 0 15px 0; font-size: 20px; }
         .status {
             background: #16213e;
             padding: 15px;
@@ -66,10 +67,10 @@ const char index_html[] PROGMEM = R"rawliteral(
             display: none;
         }
         .stall-warning.active { display: block; }
-        .slider-container { 
-            background: #16213e; 
-            padding: 20px; 
-            border-radius: 10px; 
+        .slider-container {
+            background: #16213e;
+            padding: 20px;
+            border-radius: 10px;
             margin-bottom: 20px;
         }
         .slider {
@@ -88,9 +89,9 @@ const char index_html[] PROGMEM = R"rawliteral(
             border-radius: 50%;
             cursor: pointer;
         }
-        .buttons { 
-            display: flex; 
-            gap: 10px; 
+        .buttons {
+            display: flex;
+            gap: 10px;
             justify-content: center;
             flex-wrap: wrap;
         }
@@ -108,11 +109,69 @@ const char index_html[] PROGMEM = R"rawliteral(
         .btn-reverse { background: #ff5252; color: white; }
         .btn-stop { background: #ff9100; color: white; flex-basis: 100%; }
         .btn:hover { filter: brightness(1.1); }
-        .speed-value { 
-            font-size: 48px; 
-            color: #00d9ff; 
+        .speed-value {
+            font-size: 48px;
+            color: #00d9ff;
             margin: 10px 0;
         }
+        .section-divider {
+            border-top: 2px solid #0f3460;
+            margin: 30px 0;
+        }
+        .pingpong-section {
+            background: #16213e;
+            padding: 20px;
+            border-radius: 10px;
+            margin-bottom: 20px;
+        }
+        .pingpong-status {
+            padding: 10px;
+            border-radius: 5px;
+            margin-bottom: 15px;
+            font-weight: bold;
+        }
+        .pingpong-status.active {
+            background: #00c853;
+            color: white;
+        }
+        .pingpong-status.inactive {
+            background: #444;
+            color: #aaa;
+        }
+        .setting-row {
+            display: flex;
+            justify-content: space-between;
+            align-items: center;
+            margin-bottom: 10px;
+        }
+        .setting-row label {
+            text-align: left;
+            flex: 1;
+        }
+        .setting-row .value {
+            color: #00d9ff;
+            font-weight: bold;
+            min-width: 60px;
+        }
+        .setting-slider {
+            width: 100%;
+            height: 20px;
+            -webkit-appearance: none;
+            background: #0f3460;
+            border-radius: 10px;
+            outline: none;
+            margin-top: 5px;
+        }
+        .setting-slider::-webkit-slider-thumb {
+            -webkit-appearance: none;
+            width: 25px;
+            height: 25px;
+            background: #00d9ff;
+            border-radius: 50%;
+            cursor: pointer;
+        }
+        .btn-pingpong-start { background: #9c27b0; color: white; }
+        .btn-pingpong-stop { background: #607d8b; color: white; }
     </style>
 </head>
 <body>
@@ -149,6 +208,43 @@ const char index_html[] PROGMEM = R"rawliteral(
             <button class="btn btn-reverse" onclick="setDir(-1)">REVERSE</button>
             <button class="btn btn-stop" onclick="stopMotor()">STOP</button>
         </div>
+        
+        <div class="section-divider"></div>
+        
+        <h2>🏓 Pingpong Mode</h2>
+        
+        <div class="pingpong-section">
+            <div class="pingpong-status inactive" id="pingpongStatus">INACTIVE</div>
+            
+            <div class="setting-row">
+                <label>Speed</label>
+                <span class="value"><span id="ppSpeedVal">50</span>%</span>
+            </div>
+            <input type="range" class="setting-slider" id="ppSpeed" min="10" max="100" value="50">
+            
+            <div class="setting-row" style="margin-top:15px;">
+                <label>Time before return</label>
+                <span class="value"><span id="ppTimeVal">2.0</span>s</span>
+            </div>
+            <input type="range" class="setting-slider" id="ppTime" min="500" max="10000" value="2000" step="100">
+            
+            <div class="setting-row" style="margin-top:15px;">
+                <label>Speed randomness</label>
+                <span class="value"><span id="ppSpeedRandVal">0</span>%</span>
+            </div>
+            <input type="range" class="setting-slider" id="ppSpeedRand" min="0" max="50" value="0">
+            
+            <div class="setting-row" style="margin-top:15px;">
+                <label>Time randomness</label>
+                <span class="value"><span id="ppTimeRandVal">0</span>%</span>
+            </div>
+            <input type="range" class="setting-slider" id="ppTimeRand" min="0" max="50" value="0">
+        </div>
+        
+        <div class="buttons">
+            <button class="btn btn-pingpong-start" onclick="startPingpong()">START PINGPONG</button>
+            <button class="btn btn-pingpong-stop" onclick="stopPingpong()">STOP PINGPONG</button>
+        </div>
     </div>
 
     <script>
@@ -157,6 +253,17 @@ const char index_html[] PROGMEM = R"rawliteral(
         const dirStatus = document.getElementById('dirStatus');
         let currentDir = 0;
         
+        // Pingpong controls
+        const ppSpeed = document.getElementById('ppSpeed');
+        const ppTime = document.getElementById('ppTime');
+        const ppSpeedRand = document.getElementById('ppSpeedRand');
+        const ppTimeRand = document.getElementById('ppTimeRand');
+        const ppSpeedVal = document.getElementById('ppSpeedVal');
+        const ppTimeVal = document.getElementById('ppTimeVal');
+        const ppSpeedRandVal = document.getElementById('ppSpeedRandVal');
+        const ppTimeRandVal = document.getElementById('ppTimeRandVal');
+        const ppStatus = document.getElementById('pingpongStatus');
+        
         slider.oninput = function() {
             speedVal.textContent = this.value;
         };
@@ -167,6 +274,12 @@ const char index_html[] PROGMEM = R"rawliteral(
                 .then(console.log);
         };
         
+        // Pingpong slider handlers
+        ppSpeed.oninput = function() { ppSpeedVal.textContent = this.value; };
+        ppTime.oninput = function() { ppTimeVal.textContent = (this.value / 1000).toFixed(1); };
+        ppSpeedRand.oninput = function() { ppSpeedRandVal.textContent = this.value; };
+        ppTimeRand.oninput = function() { ppTimeRandVal.textContent = this.value; };
+        
         function setDir(dir) {
             currentDir = dir;
             fetch('/direction?value=' + dir)
@@ -183,6 +296,24 @@ const char index_html[] PROGMEM = R"rawliteral(
                 .then(() => updateStatus());
         }
         
+        function startPingpong() {
+            const params = new URLSearchParams({
+                speed: ppSpeed.value,
+                time: ppTime.value,
+                speedRand: ppSpeedRand.value,
+                timeRand: ppTimeRand.value
+            });
+            fetch('/pingpong/start?' + params)
+                .then(r => r.text())
+                .then(console.log);
+        }
+        
+        function stopPingpong() {
+            fetch('/pingpong/stop')
+                .then(r => r.text())
+                .then(console.log);
+        }
+        
         function updateStatus() {
             if (currentDir > 0) dirStatus.textContent = 'FORWARD';
             else if (currentDir < 0) dirStatus.textContent = 'REVERSE';
@@ -210,6 +341,26 @@ const char index_html[] PROGMEM = R"rawliteral(
                     } else {
                         stallWarning.classList.remove('active');
                     }
+                    
+                    // Update pingpong status
+                    if (data.pingpong) {
+                        ppStatus.textContent = 'ACTIVE';
+                        ppStatus.classList.remove('inactive');
+                        ppStatus.classList.add('active');
+                        // Update sliders to match current settings
+                        ppSpeed.value = data.ppSpeed;
+                        ppSpeedVal.textContent = data.ppSpeed;
+                        ppTime.value = data.ppTime;
+                        ppTimeVal.textContent = (data.ppTime / 1000).toFixed(1);
+                        ppSpeedRand.value = data.ppSpeedRand;
+                        ppSpeedRandVal.textContent = data.ppSpeedRand;
+                        ppTimeRand.value = data.ppTimeRand;
+                        ppTimeRandVal.textContent = data.ppTimeRand;
+                    } else {
+                        ppStatus.textContent = 'INACTIVE';
+                        ppStatus.classList.remove('active');
+                        ppStatus.classList.add('inactive');
+                    }
                 });
         }
         
@@ -255,16 +406,51 @@ void handleStatus() {
                   ",\"direction\":" + String(motor.getDirection()) +
                   ",\"currentR\":" + String(motor.getCurrentRight(), 2) +
                   ",\"currentL\":" + String(motor.getCurrentLeft(), 2) +
-                  ",\"stalled\":" + (motor.isStalled() ? "true" : "false") + "}";
+                  ",\"stalled\":" + (motor.isStalled() ? "true" : "false") +
+                  ",\"pingpong\":" + (motor.isPingpongActive() ? "true" : "false") +
+                  ",\"ppSpeed\":" + String(motor.getPingpongSpeed()) +
+                  ",\"ppTime\":" + String(motor.getPingpongTime()) +
+                  ",\"ppSpeedRand\":" + String(motor.getPingpongSpeedRandom()) +
+                  ",\"ppTimeRand\":" + String(motor.getPingpongTimeRandom()) + "}";
     server.send(200, "application/json", json);
 }
 
+void handlePingpongStart() {
+    int speed = 50;
+    int time = 2000;
+    int speedRand = 0;
+    int timeRand = 0;
+    
+    if (server.hasArg("speed")) {
+        speed = server.arg("speed").toInt();
+    }
+    if (server.hasArg("time")) {
+        time = server.arg("time").toInt();
+    }
+    if (server.hasArg("speedRand")) {
+        speedRand = server.arg("speedRand").toInt();
+    }
+    if (server.hasArg("timeRand")) {
+        timeRand = server.arg("timeRand").toInt();
+    }
+    
+    motor.startPingpong(speed, time, speedRand, timeRand);
+    server.send(200, "text/plain", "OK");
+}
+
+void handlePingpongStop() {
+    motor.stopPingpong();
+    server.send(200, "text/plain", "OK");
+}
+
 void setupWebServer() {
     server.on("/", handleRoot);
     server.on("/speed", handleSpeed);
     server.on("/direction", handleDirection);
     server.on("/stop", handleStop);
     server.on("/status", handleStatus);
+    server.on("/pingpong/start", handlePingpongStart);
+    server.on("/pingpong/stop", handlePingpongStop);
     
     server.begin();
     Serial.println("Web server started on port 80");