apps: sync cell constant K with device, verify export format compatibility

cue-ios/CueIOS/AppState.swift

@@ -270,6 +270,10 @@ final class AppState {
             if !hasRefs {
                 status = "No device refs"
             }
+
+        case .cellK(let k):
+            calCellConstant = Double(k)
+            status = String(format: "Device cell constant: %.4f cm\u{207B}\u{00B9}", k)
         }
     }
 

cue-ios/CueIOS/BLE/BLEManager.swift

@@ -209,6 +209,7 @@ extension BLEManager: CBPeripheralDelegate {
         if characteristic.isNotifying {
             state = .connected
             sendCommand(buildSysexGetConfig())
+            sendCommand(buildSysexGetCellK())
         }
     }
 

cue-ios/CueIOS/Models/Protocol.swift

@@ -24,6 +24,7 @@ let RSP_CL_RESULT:    UInt8 = 0x0D
 let RSP_CL_END:       UInt8 = 0x0E
 let RSP_PH_RESULT:    UInt8 = 0x0F
 let RSP_TEMP:         UInt8 = 0x10
+let RSP_CELL_K:       UInt8 = 0x11
 let RSP_REF_FRAME:    UInt8 = 0x20
 let RSP_REF_LP_RANGE: UInt8 = 0x21
 let RSP_REFS_DONE:    UInt8 = 0x22
@@ -43,6 +44,8 @@ let CMD_STOP_AMP:      UInt8 = 0x22
 let CMD_START_CL:      UInt8 = 0x23
 let CMD_START_PH:      UInt8 = 0x24
 let CMD_START_CLEAN:   UInt8 = 0x25
+let CMD_SET_CELL_K:    UInt8 = 0x28
+let CMD_GET_CELL_K:    UInt8 = 0x29
 let CMD_START_REFS:    UInt8 = 0x30
 let CMD_GET_REFS:      UInt8 = 0x31
 let CMD_CLEAR_REFS:    UInt8 = 0x32
@@ -119,6 +122,7 @@ enum EisMessage {
     case refLpRange(mode: UInt8, lowIdx: UInt8, highIdx: UInt8)
     case refsDone
     case refStatus(hasRefs: Bool)
+    case cellK(Float)
 }
 
 // MARK: - Response parser
@@ -247,6 +251,9 @@ func parseSysex(_ data: [UInt8]) -> EisMessage? {
     case RSP_REF_STATUS where p.count >= 1:
         return .refStatus(hasRefs: p[0] != 0)
 
+    case RSP_CELL_K where p.count >= 5:
+        return .cellK(decodeFloat(p, at: 0))
+
     default:
         return nil
     }
@@ -353,3 +360,14 @@ func buildSysexGetRefs() -> [UInt8] {
 func buildSysexClearRefs() -> [UInt8] {
     [0xF0, sysexMfr, CMD_CLEAR_REFS, 0xF7]
 }
+
+func buildSysexSetCellK(_ k: Float) -> [UInt8] {
+    var sx: [UInt8] = [0xF0, sysexMfr, CMD_SET_CELL_K]
+    sx.append(contentsOf: encodeFloat(k))
+    sx.append(0xF7)
+    return sx
+}
+
+func buildSysexGetCellK() -> [UInt8] {
+    [0xF0, sysexMfr, CMD_GET_CELL_K, 0xF7]
+}

cue-ios/CueIOS/Views/CalibrateView.swift

@@ -101,6 +101,7 @@ struct CalibrateView: View {
                 let k = cellConstant(kappaMsCm: kappa, rsOhm: Double(rs))
                 state.calRs = Double(rs)
                 state.calCellConstant = k
+                state.send(buildSysexSetCellK(Float(k)))
                 state.status = String(format: "K = %.4f cm\u{207B}\u{00B9} (Rs = %.1f \u{2126})", k, rs)
             }
             .disabled(state.eisPoints.isEmpty)

cue/src/app.rs

@@ -571,6 +571,7 @@ impl App {
                 self.cmd_tx = Some(tx);
                 self.ble_connected = true;
                 self.send_cmd(&protocol::build_sysex_get_config());
+                self.send_cmd(&protocol::build_sysex_get_cell_k());
             }
             Message::BleStatus(s) => {
                 if s.contains("Reconnecting") || s.contains("Looking") {
@@ -740,6 +741,10 @@ impl App {
                         self.status = "No device refs".into();
                     }
                 }
+                EisMessage::CellK(k) => {
+                    self.cal_cell_constant = Some(k);
+                    self.status = format!("Device cell constant: {:.4} cm-1", k);
+                }
             },
             Message::TabSelected(t) => {
                 if t == Tab::Browse {
@@ -951,6 +956,7 @@ impl App {
                 if let Some(rs) = extract_rs(&self.eis_points) {
                     let k = cell_constant(kappa, rs);
                     self.cal_cell_constant = Some(k);
+                    self.send_cmd(&protocol::build_sysex_set_cell_k(k));
                     self.status = format!("Cell constant: {:.4} cm-1 (Rs={:.1} ohm)", k, rs);
                 } else {
                     self.status = "No valid EIS data for Rs extraction".into();

cue/src/protocol.rs

@@ -24,6 +24,7 @@ pub const RSP_TEMP: u8 = 0x10;
 pub const RSP_REF_FRAME: u8 = 0x20;
 pub const RSP_REF_LP_RANGE: u8 = 0x21;
 pub const RSP_REFS_DONE: u8 = 0x22;
+pub const RSP_CELL_K: u8 = 0x11;
 pub const RSP_REF_STATUS: u8 = 0x23;
 
 /* Cue → ESP32 */
@@ -41,6 +42,8 @@ pub const CMD_GET_TEMP: u8 = 0x17;
 pub const CMD_START_CL: u8 = 0x23;
 pub const CMD_START_PH: u8 = 0x24;
 pub const CMD_START_CLEAN: u8 = 0x25;
+pub const CMD_SET_CELL_K: u8 = 0x28;
+pub const CMD_GET_CELL_K: u8 = 0x29;
 pub const CMD_START_REFS: u8 = 0x30;
 pub const CMD_GET_REFS: u8 = 0x31;
 pub const CMD_CLEAR_REFS: u8 = 0x32;
@@ -254,6 +257,7 @@ pub enum EisMessage {
     RefLpRange { mode: u8, low_idx: u8, high_idx: u8 },
     RefsDone,
     RefStatus { has_refs: bool },
+    CellK(f32),
 }
 
 fn decode_u16(data: &[u8]) -> u16 {
@@ -405,6 +409,10 @@ pub fn parse_sysex(data: &[u8]) -> Option<EisMessage> {
         RSP_REF_STATUS if data.len() >= 3 => {
             Some(EisMessage::RefStatus { has_refs: data[2] != 0 })
         }
+        RSP_CELL_K if data.len() >= 7 => {
+            let p = &data[2..];
+            Some(EisMessage::CellK(decode_float(&p[0..5])))
+        }
         _ => None,
     }
 }
@@ -508,3 +516,14 @@ pub fn build_sysex_get_refs() -> Vec<u8> {
 pub fn build_sysex_clear_refs() -> Vec<u8> {
     vec![0xF0, SYSEX_MFR, CMD_CLEAR_REFS, 0xF7]
 }
+
+pub fn build_sysex_set_cell_k(k: f32) -> Vec<u8> {
+    let mut sx = vec![0xF0, SYSEX_MFR, CMD_SET_CELL_K];
+    sx.extend_from_slice(&encode_float(k));
+    sx.push(0xF7);
+    sx
+}
+
+pub fn build_sysex_get_cell_k() -> Vec<u8> {
+    vec![0xF0, SYSEX_MFR, CMD_GET_CELL_K, 0xF7]
+}