Add 4mA-20mA sensor type options (pressure vs ultrasonic)

Co-authored-by: dorkmo <[email protected]>

Author: Copilot

TankAlarm-112025-Client-BluesOpta/TankAlarm-112025-Client-BluesOpta.ino

@@ -210,6 +210,14 @@ enum SensorType : uint8_t {
   SENSOR_HALL_EFFECT_RPM = 3
 };
 
+// 4-20mA current loop sensor subtypes
+enum CurrentLoopSensorType : uint8_t {
+  CURRENT_LOOP_PRESSURE = 0,    // Pressure sensor mounted near bottom of tank (e.g., Dwyer 626-06-CB-P1-E5-S1)
+                                // 4mA = empty (0 PSI), 20mA = full (max PSI)
+  CURRENT_LOOP_ULTRASONIC = 1   // Ultrasonic sensor mounted on top of tank (e.g., Siemens Sitrans LU240)
+                                // 4mA = full (sensor close to liquid), 20mA = empty (sensor far from liquid)
+};
+
 // Relay trigger conditions - which alarm type triggers the relay
 enum RelayTrigger : uint8_t {
   RELAY_TRIGGER_ANY = 0,   // Trigger on any alarm (high or low)
@@ -251,6 +259,10 @@ struct TankConfig {
   // Digital sensor (float switch) specific settings
   char digitalTrigger[16]; // 'activated' or 'not_activated' - when to trigger alarm for digital sensors
   char digitalSwitchMode[4]; // 'NO' for normally-open, 'NC' for normally-closed (default: NO)
+  // 4-20mA current loop sensor settings
+  CurrentLoopSensorType currentLoopType; // Pressure (bottom-mounted) or Ultrasonic (top-mounted)
+  float sensorMountHeight; // For ultrasonic: distance from sensor to tank bottom (inches)
+                           // For pressure: height of sensor above tank bottom (inches, usually 0-2)
 };
 
 struct ClientConfig {
@@ -633,6 +645,8 @@ static void createDefaultConfig(ClientConfig &cfg) {
   cfg.tanks[0].relayMode = RELAY_MODE_MOMENTARY; // Default: momentary 30 min activation
   cfg.tanks[0].digitalTrigger[0] = '\0'; // Not a digital sensor by default
   strlcpy(cfg.tanks[0].digitalSwitchMode, "NO", sizeof(cfg.tanks[0].digitalSwitchMode)); // Default: normally-open
+  cfg.tanks[0].currentLoopType = CURRENT_LOOP_PRESSURE; // Default: pressure sensor (most common)
+  cfg.tanks[0].sensorMountHeight = 0.0f; // Default: sensor at tank bottom
 }
 
 static bool loadConfigFromFlash(ClientConfig &cfg) {
@@ -768,6 +782,15 @@ static bool loadConfigFromFlash(ClientConfig &cfg) {
     } else {
       strlcpy(cfg.tanks[i].digitalSwitchMode, "NO", sizeof(cfg.tanks[i].digitalSwitchMode)); // Default: normally-open
     }
+    // Load 4-20mA current loop sensor type (pressure or ultrasonic)
+    const char *currentLoopTypeStr = t["currentLoopType"].as<const char *>();
+    if (currentLoopTypeStr && strcmp(currentLoopTypeStr, "ultrasonic") == 0) {
+      cfg.tanks[i].currentLoopType = CURRENT_LOOP_ULTRASONIC;
+    } else {
+      cfg.tanks[i].currentLoopType = CURRENT_LOOP_PRESSURE; // Default: pressure sensor
+    }
+    // Load sensor mount height (for calibration)
+    cfg.tanks[i].sensorMountHeight = t["sensorMountHeight"].is<float>() ? t["sensorMountHeight"].as<float>() : 0.0f;
   }
 
   return true;
@@ -838,6 +861,13 @@ static bool saveConfigToFlash(const ClientConfig &cfg) {
     }
     // Save digital switch mode (NO/NC)
     t["digitalSwitchMode"] = cfg.tanks[i].digitalSwitchMode;
+    // Save 4-20mA current loop sensor type
+    switch (cfg.tanks[i].currentLoopType) {
+      case CURRENT_LOOP_ULTRASONIC: t["currentLoopType"] = "ultrasonic"; break;
+      default: t["currentLoopType"] = "pressure"; break;
+    }
+    // Save sensor mount height (for calibration)
+    t["sensorMountHeight"] = cfg.tanks[i].sensorMountHeight;
   }
 
   #if defined(ARDUINO_OPTA) || defined(ARDUINO_ARCH_MBED)
@@ -895,13 +925,20 @@ static void printHardwareRequirements(const ClientConfig &cfg) {
   bool needsCurrentLoop = false;
   bool needsRelayOutput = false;
   bool needsRpmSensor = false;
+  bool hasPressureSensor = false;
+  bool hasUltrasonicSensor = false;
 
   for (uint8_t i = 0; i < cfg.tankCount; ++i) {
     if (cfg.tanks[i].sensorType == SENSOR_ANALOG) {
       needsAnalogExpansion = true;
     }
     if (cfg.tanks[i].sensorType == SENSOR_CURRENT_LOOP) {
       needsCurrentLoop = true;
+      if (cfg.tanks[i].currentLoopType == CURRENT_LOOP_PRESSURE) {
+        hasPressureSensor = true;
+      } else if (cfg.tanks[i].currentLoopType == CURRENT_LOOP_ULTRASONIC) {
+        hasUltrasonicSensor = true;
+      }
     }
     if (cfg.tanks[i].sensorType == SENSOR_HALL_EFFECT_RPM) {
       needsRpmSensor = true;
@@ -919,6 +956,12 @@ static void printHardwareRequirements(const ClientConfig &cfg) {
   }
   if (needsCurrentLoop) {
     Serial.println(F("Current loop interface required (4-20mA module)"));
+    if (hasPressureSensor) {
+      Serial.println(F("  - Pressure sensor (bottom-mounted, e.g., Dwyer 626-06-CB-P1-E5-S1)"));
+    }
+    if (hasUltrasonicSensor) {
+      Serial.println(F("  - Ultrasonic sensor (top-mounted, e.g., Siemens Sitrans LU240)"));
+    }
   }
   if (needsRpmSensor) {
     Serial.println(F("Hall effect RPM sensor connected to digital input"));
@@ -1280,6 +1323,19 @@ static void applyConfigUpdate(const JsonDocument &doc) {
           strlcpy(gConfig.tanks[i].digitalSwitchMode, "NO", sizeof(gConfig.tanks[i].digitalSwitchMode));
         }
       }
+      // Handle 4-20mA current loop sensor type (pressure or ultrasonic)
+      if (t.containsKey("currentLoopType")) {
+        const char *currentLoopTypeStr = t["currentLoopType"].as<const char *>();
+        if (currentLoopTypeStr && strcmp(currentLoopTypeStr, "ultrasonic") == 0) {
+          gConfig.tanks[i].currentLoopType = CURRENT_LOOP_ULTRASONIC;
+        } else {
+          gConfig.tanks[i].currentLoopType = CURRENT_LOOP_PRESSURE;
+        }
+      }
+      // Handle sensor mount height (for calibration)
+      if (t.containsKey("sensorMountHeight")) {
+        gConfig.tanks[i].sensorMountHeight = t["sensorMountHeight"].as<float>();
+      }
     }
   }
 
@@ -1480,7 +1536,33 @@ static float readTankSensor(uint8_t idx) {
       if (milliamps < 0.0f) {
         return gTankState[idx].currentInches; // keep previous on failure
       }
-      return linearMap(milliamps, 4.0f, 20.0f, 0.0f, cfg.maxValue);
+      
+      // Handle different 4-20mA sensor types
+      float levelInches;
+      if (cfg.currentLoopType == CURRENT_LOOP_ULTRASONIC) {
+        // Ultrasonic sensor mounted on TOP of tank (e.g., Siemens Sitrans LU240)
+        // 4mA = full tank (sensor close to liquid surface)
+        // 20mA = empty tank (sensor far from liquid surface)
+        // sensorMountHeight = distance from sensor to tank bottom when empty
+        // maxValue = tank height (max liquid level)
+        // The sensor measures distance from sensor to liquid surface
+        // Distance at 4mA = 0 (full), Distance at 20mA = sensorMountHeight (empty)
+        float distanceFromSensor = linearMap(milliamps, 4.0f, 20.0f, 0.0f, cfg.sensorMountHeight);
+        levelInches = cfg.sensorMountHeight - distanceFromSensor;
+        // Clamp to valid range
+        if (levelInches < 0.0f) levelInches = 0.0f;
+        if (levelInches > cfg.maxValue) levelInches = cfg.maxValue;
+      } else {
+        // Pressure sensor mounted near BOTTOM of tank (e.g., Dwyer 626-06-CB-P1-E5-S1)
+        // 4mA = empty tank (0 PSI / no liquid above sensor)
+        // 20mA = full tank (max PSI / max liquid height above sensor)
+        // sensorMountHeight = height of sensor above tank bottom (usually 0-2 inches)
+        // maxValue = maximum liquid height the sensor measures (corresponds to max PSI)
+        float rawLevel = linearMap(milliamps, 4.0f, 20.0f, 0.0f, cfg.maxValue);
+        // Add mount height offset (sensor is mounted above tank bottom)
+        levelInches = rawLevel + cfg.sensorMountHeight;
+      }
+      return levelInches;
     }
     case SENSOR_HALL_EFFECT_RPM: {
       // Hall effect RPM sensor - sample pulses for a few seconds each measurement period

TankAlarm-112025-Server-BluesOpta/TankAlarm-112025-Server-BluesOpta.ino

@@ -675,6 +675,12 @@ static const char CONFIG_GENERATOR_HTML[] PROGMEM = R"HTML(
       { value: 3, label: 'Hall Effect RPM' }
     ];
 
+    // 4-20mA current loop sensor subtypes
+    const currentLoopTypes = [
+      { value: 'pressure', label: 'Pressure Sensor (Bottom-Mounted)', tooltip: 'Pressure sensor mounted near tank bottom (e.g., Dwyer 626-06-CB-P1-E5-S1). 4mA = empty, 20mA = full.' },
+      { value: 'ultrasonic', label: 'Ultrasonic Sensor (Top-Mounted)', tooltip: 'Ultrasonic level sensor mounted on tank top (e.g., Siemens Sitrans LU240). 4mA = full, 20mA = empty.' }
+    ];
+
     const monitorTypes = [
       { value: 'tank', label: 'Tank Level' },
       { value: 'gas', label: 'Gas Pressure' },
@@ -737,6 +743,13 @@ static const char CONFIG_GENERATOR_HTML[] PROGMEM = R"HTML(
               </select>
             </label>
             <label class="field pulses-per-rev-field" style="display: none;"><span>Pulses/Rev</span><input type="number" class="pulses-per-rev" value="1" min="1" max="255"></label>
+            <label class="field current-loop-type-field" style="display: none;"><span>4-20mA Sensor Type<span class="tooltip-icon" tabindex="0" data-tooltip="Select the type of 4-20mA sensor: Pressure sensors are mounted near the tank bottom and measure liquid pressure. Ultrasonic sensors are mounted on top of the tank and measure distance to the liquid surface.">?</span></span>
+              <select class="current-loop-type" onchange="updateCurrentLoopFields(${id})">
+                <option value="pressure">Pressure Sensor (Bottom-Mounted)</option>
+                <option value="ultrasonic">Ultrasonic Sensor (Top-Mounted)</option>
+              </select>
+            </label>
+            <label class="field sensor-mount-height-field" style="display: none;"><span><span class="mount-height-label">Sensor Mount Height (in)</span><span class="tooltip-icon mount-height-tooltip" tabindex="0" data-tooltip="For pressure sensors: height of sensor above tank bottom (usually 0-2 inches). For ultrasonic sensors: distance from sensor to tank bottom when empty.">?</span></span><input type="number" class="sensor-mount-height" value="0" step="0.1" min="0"></label>
             <label class="field height-field"><span><span class="height-label">Height (in)</span><span class="tooltip-icon height-tooltip" tabindex="0" data-tooltip="Maximum height or capacity of the tank in inches. Used to calculate fill percentage and set alarm thresholds relative to tank size.">?</span></span><input type="number" class="tank-height" value="120"></label>
           </div>
           
@@ -746,6 +759,22 @@ static const char CONFIG_GENERATOR_HTML[] PROGMEM = R"HTML(
             <strong>Wiring Note:</strong> For both NO and NC switches, connect the switch between the input pin and GND. The software uses an internal pull-up resistor and interprets the signal based on your selected switch mode.
           </div>
           
+          <!-- 4-20mA sensor info box (shown only for current loop sensors) -->
+          <div class="current-loop-sensor-info" style="display: none; background: var(--chip); border: 1px solid var(--card-border); border-radius: 8px; padding: 12px; margin-top: 8px; font-size: 0.9rem; color: var(--muted);">
+            <div class="pressure-sensor-info">
+              <strong>Pressure Sensor (Bottom-Mounted):</strong> Installed near the bottom of the tank, this sensor measures the pressure of the liquid column above it. Examples: Dwyer 626-06-CB-P1-E5-S1 (0-5 PSI).<br>
+              • 4mA = Empty tank (0 PSI)<br>
+              • 20mA = Full tank (max PSI)<br>
+              • Mount Height: Distance from sensor to tank bottom (usually 0-2 inches)
+            </div>
+            <div class="ultrasonic-sensor-info" style="display: none;">
+              <strong>Ultrasonic Sensor (Top-Mounted):</strong> Mounted on top of the tank, this sensor measures the distance from the sensor to the liquid surface. Examples: Siemens Sitrans LU240.<br>
+              • 4mA = Full tank (liquid close to sensor)<br>
+              • 20mA = Empty tank (liquid far from sensor)<br>
+              • Sensor Mount Height: Distance from sensor to tank bottom when empty
+            </div>
+          </div>
+          
           <button type="button" class="add-section-btn add-alarm-btn" onclick="toggleAlarmSection(${id})">+ Add Alarm</button>
           <div class="collapsible-section alarm-section">
             <h4 style="margin: 16px 0 8px; font-size: 0.95rem; border-top: 1px solid var(--card-border); padding-top: 12px;"><span class="alarm-section-title">Alarm Thresholds</span> <button type="button" class="remove-btn" onclick="removeAlarmSection(${id})" style="float: right;">Remove Alarm</button></h4>
@@ -998,49 +1027,106 @@ static const char CONFIG_GENERATOR_HTML[] PROGMEM = R"HTML(
       const heightLabel = card.querySelector('.height-label');
       const heightTooltip = card.querySelector('.height-tooltip');
       const digitalInfoBox = card.querySelector('.digital-sensor-info');
+      const currentLoopInfoBox = card.querySelector('.current-loop-sensor-info');
       const alarmThresholdsGrid = card.querySelector('.alarm-thresholds-grid');
       const digitalAlarmGrid = card.querySelector('.digital-alarm-grid');
       const alarmSectionTitle = card.querySelector('.alarm-section-title');
       const pulsesPerRevField = card.querySelector('.pulses-per-rev-field');
       const switchModeField = card.querySelector('.switch-mode-field');
+      const currentLoopTypeField = card.querySelector('.current-loop-type-field');
+      const sensorMountHeightField = card.querySelector('.sensor-mount-height-field');
       
       // Digital Input (Float Switch) - type === 0
       if (type === 0) {
         // Hide height field (not applicable for float switches)
         heightField.style.display = 'none';
         // Show digital sensor info box
         digitalInfoBox.style.display = 'block';
+        currentLoopInfoBox.style.display = 'none';
         // Show switch mode selector for digital sensors
         switchModeField.style.display = 'flex';
+        // Hide current loop fields
+        currentLoopTypeField.style.display = 'none';
+        sensorMountHeightField.style.display = 'none';
         // Update alarm section for digital sensors
         alarmThresholdsGrid.style.display = 'none';
         digitalAlarmGrid.style.display = 'grid';
         alarmSectionTitle.textContent = 'Float Switch Alarm';
         pulsesPerRevField.style.display = 'none';
+      } else if (type === 2) { // Current Loop (4-20mA)
+        heightField.style.display = 'flex';
+        heightLabel.textContent = 'Tank Height (in)';
+        heightTooltip.setAttribute('data-tooltip', 'Maximum height of liquid in the tank in inches. For ultrasonic sensors, this is the distance the sensor measures at full tank.');
+        digitalInfoBox.style.display = 'none';
+        currentLoopInfoBox.style.display = 'block';
+        switchModeField.style.display = 'none';
+        // Show current loop type and mount height fields
+        currentLoopTypeField.style.display = 'flex';
+        sensorMountHeightField.style.display = 'flex';
+        alarmThresholdsGrid.style.display = 'grid';
+        digitalAlarmGrid.style.display = 'none';
+        alarmSectionTitle.textContent = 'Alarm Thresholds';
+        pulsesPerRevField.style.display = 'none';
+        // Update current loop specific info
+        updateCurrentLoopFields(id);
       } else if (type === 3) { // Hall Effect RPM
         heightField.style.display = 'flex';
         heightLabel.textContent = 'Max RPM';
         heightTooltip.setAttribute('data-tooltip', 'Maximum expected RPM value. Used for alarm threshold reference.');
         digitalInfoBox.style.display = 'none';
+        currentLoopInfoBox.style.display = 'none';
         switchModeField.style.display = 'none';
+        currentLoopTypeField.style.display = 'none';
+        sensorMountHeightField.style.display = 'none';
         alarmThresholdsGrid.style.display = 'grid';
         digitalAlarmGrid.style.display = 'none';
         alarmSectionTitle.textContent = 'Alarm Thresholds';
         pulsesPerRevField.style.display = 'flex';
       } else {
-        // Analog or Current Loop sensors
+        // Analog sensors
         heightField.style.display = 'flex';
         heightLabel.textContent = 'Height (in)';
         heightTooltip.setAttribute('data-tooltip', 'Maximum height or capacity of the tank in inches. Used to calculate fill percentage and set alarm thresholds relative to tank size.');
         digitalInfoBox.style.display = 'none';
+        currentLoopInfoBox.style.display = 'none';
         switchModeField.style.display = 'none';
+        currentLoopTypeField.style.display = 'none';
+        sensorMountHeightField.style.display = 'none';
         alarmThresholdsGrid.style.display = 'grid';
         digitalAlarmGrid.style.display = 'none';
         alarmSectionTitle.textContent = 'Alarm Thresholds';
         pulsesPerRevField.style.display = 'none';
       }
     };
 
+    window.updateCurrentLoopFields = function(id) {
+      const card = document.getElementById(`sensor-${id}`);
+      const currentLoopType = card.querySelector('.current-loop-type').value;
+      const currentLoopInfoBox = card.querySelector('.current-loop-sensor-info');
+      const pressureInfo = currentLoopInfoBox.querySelector('.pressure-sensor-info');
+      const ultrasonicInfo = currentLoopInfoBox.querySelector('.ultrasonic-sensor-info');
+      const mountHeightLabel = card.querySelector('.mount-height-label');
+      const mountHeightTooltip = card.querySelector('.mount-height-tooltip');
+      const heightLabel = card.querySelector('.height-label');
+      const heightTooltip = card.querySelector('.height-tooltip');
+      
+      if (currentLoopType === 'ultrasonic') {
+        pressureInfo.style.display = 'none';
+        ultrasonicInfo.style.display = 'block';
+        mountHeightLabel.textContent = 'Sensor Mount Height (in)';
+        mountHeightTooltip.setAttribute('data-tooltip', 'Distance from the ultrasonic sensor to the tank bottom when empty. This is used to calculate the actual liquid level.');
+        heightLabel.textContent = 'Tank Height (in)';
+        heightTooltip.setAttribute('data-tooltip', 'Maximum liquid height in the tank. When the tank is full, the liquid level equals this value.');
+      } else {
+        pressureInfo.style.display = 'block';
+        ultrasonicInfo.style.display = 'none';
+        mountHeightLabel.textContent = 'Sensor Mount Height (in)';
+        mountHeightTooltip.setAttribute('data-tooltip', 'Height of the pressure sensor above the tank bottom (usually 0-2 inches). This offset is added to the measured level.');
+        heightLabel.textContent = 'Max Measured Height (in)';
+        heightTooltip.setAttribute('data-tooltip', 'Maximum liquid height the sensor can measure (corresponds to 20mA / max PSI). Does not include the sensor mount height offset.');
+      }
+    };
+
     document.getElementById('addSensorBtn').addEventListener('click', addSensor);
 
     function sensorKeyFromValue(value) {
@@ -1128,6 +1214,14 @@ static const char CONFIG_GENERATOR_HTML[] PROGMEM = R"HTML(
           tank.digitalSwitchMode = switchMode;  // 'NO' or 'NC'
         }
 
+        // Add current loop sensor type and mount height for 4-20mA sensors
+        if (sensor === 'current') {
+          const currentLoopType = card.querySelector('.current-loop-type').value;
+          const sensorMountHeight = parseFloat(card.querySelector('.sensor-mount-height').value) || 0;
+          tank.currentLoopType = currentLoopType;  // 'pressure' or 'ultrasonic'
+          tank.sensorMountHeight = sensorMountHeight;
+        }
+
         // Handle alarms differently based on sensor type
         if (alarmSectionVisible) {
           if (sensor === 'digital') {