desktop: add pH cal protocol, Q/HQ peak detection, and state

cue/src/app.rs

@@ -100,6 +100,11 @@ pub enum Message {
     CalComputeK,
     ClCalKnownPpmChanged(String),
     ClSetFactor,
+    /* pH calibration */
+    PhCalKnownChanged(String),
+    PhAddCalPoint,
+    PhClearCalPoints,
+    PhComputeAndSetCal,
     /* Global */
     PollTemp,
     NativeMenuTick,
@@ -235,6 +240,10 @@ pub struct App {
     cal_cell_constant: Option<f32>,
     cl_factor: Option<f32>,
     cl_cal_known_ppm: String,
+    ph_slope: Option<f32>,
+    ph_offset: Option<f32>,
+    ph_cal_points: Vec<(f32, f32)>,
+    ph_cal_known: String,
 
     /* Global */
     temp_c: f32,
@@ -469,6 +478,10 @@ impl App {
             cal_cell_constant: None,
             cl_factor: None,
             cl_cal_known_ppm: String::from("5"),
+            ph_slope: None,
+            ph_offset: None,
+            ph_cal_points: vec![],
+            ph_cal_known: String::from("7.00"),
 
             temp_c: 25.0,
             conn_gen: 0,
@@ -574,6 +587,7 @@ impl App {
                 self.send_cmd(&protocol::build_sysex_get_config());
                 self.send_cmd(&protocol::build_sysex_get_cell_k());
                 self.send_cmd(&protocol::build_sysex_get_cl_factor());
+                self.send_cmd(&protocol::build_sysex_get_ph_cal());
             }
             Message::DeviceStatus(s) => {
                 if s.contains("Reconnecting") || s.contains("Connecting") {
@@ -754,6 +768,11 @@ impl App {
                     self.cl_factor = Some(f);
                     self.status = format!("Device Cl factor: {:.6}", f);
                 }
+                EisMessage::PhCal { slope, offset } => {
+                    self.ph_slope = Some(slope);
+                    self.ph_offset = Some(offset);
+                    self.status = format!("pH cal: slope={:.4} offset={:.4}", slope, offset);
+                }
             },
             Message::TabSelected(t) => {
                 if t == Tab::Browse {

cue/src/lsv_analysis.rs

@@ -66,6 +66,31 @@ pub fn find_extrema(_v: &[f32], i_smooth: &[f32], min_prominence: f32) -> Vec<(u
     candidates
 }
 
+/// Detect Q/HQ redox peak in the -100 to +600 mV window.
+/// Returns peak voltage in mV if found.
+pub fn detect_qhq_peak(points: &[LsvPoint]) -> Option<f32> {
+    if points.len() < 5 {
+        return None;
+    }
+
+    let i_vals: Vec<f32> = points.iter().map(|p| p.i_ua).collect();
+    let v_vals: Vec<f32> = points.iter().map(|p| p.v_mv).collect();
+
+    let window = 5.max(points.len() / 50);
+    let smoothed = smooth(&i_vals, window);
+
+    let i_min = smoothed.iter().copied().fold(f32::INFINITY, f32::min);
+    let i_max = smoothed.iter().copied().fold(f32::NEG_INFINITY, f32::max);
+    let prominence = (i_max - i_min) * 0.05;
+
+    let extrema = find_extrema(&v_vals, &smoothed, prominence);
+
+    extrema.iter()
+        .filter(|&&(idx, is_max)| is_max && v_vals[idx] >= -100.0 && v_vals[idx] <= 600.0)
+        .max_by(|a, b| smoothed[a.0].partial_cmp(&smoothed[b.0]).unwrap_or(std::cmp::Ordering::Equal))
+        .map(|&(idx, _)| v_vals[idx])
+}
+
 pub fn detect_peaks(points: &[LsvPoint]) -> Vec<LsvPeak> {
     if points.len() < 5 {
         return Vec::new();

cue/src/protocol.rs

@@ -27,6 +27,7 @@ pub const RSP_REFS_DONE: u8 = 0x22;
 pub const RSP_CELL_K: u8 = 0x11;
 pub const RSP_REF_STATUS: u8 = 0x23;
 pub const RSP_CL_FACTOR: u8 = 0x24;
+pub const RSP_PH_CAL: u8 = 0x25;
 
 /* Cue → ESP32 */
 pub const CMD_SET_SWEEP: u8 = 0x10;
@@ -47,6 +48,8 @@ pub const CMD_SET_CELL_K: u8 = 0x28;
 pub const CMD_GET_CELL_K: u8 = 0x29;
 pub const CMD_SET_CL_FACTOR: u8 = 0x33;
 pub const CMD_GET_CL_FACTOR: u8 = 0x34;
+pub const CMD_SET_PH_CAL: u8 = 0x35;
+pub const CMD_GET_PH_CAL: u8 = 0x36;
 pub const CMD_START_REFS: u8 = 0x30;
 pub const CMD_GET_REFS: u8 = 0x31;
 pub const CMD_CLEAR_REFS: u8 = 0x32;
@@ -262,6 +265,7 @@ pub enum EisMessage {
     RefStatus { has_refs: bool },
     CellK(f32),
     ClFactor(f32),
+    PhCal { slope: f32, offset: f32 },
 }
 
 fn decode_u16(data: &[u8]) -> u16 {
@@ -421,6 +425,13 @@ pub fn parse_sysex(data: &[u8]) -> Option<EisMessage> {
             let p = &data[2..];
             Some(EisMessage::ClFactor(decode_float(&p[0..5])))
         }
+        RSP_PH_CAL if data.len() >= 12 => {
+            let p = &data[2..];
+            Some(EisMessage::PhCal {
+                slope: decode_float(&p[0..5]),
+                offset: decode_float(&p[5..10]),
+            })
+        }
         _ => None,
     }
 }
@@ -546,3 +557,15 @@ pub fn build_sysex_set_cl_factor(f: f32) -> Vec<u8> {
 pub fn build_sysex_get_cl_factor() -> Vec<u8> {
     vec![0xF0, SYSEX_MFR, CMD_GET_CL_FACTOR, 0xF7]
 }
+
+pub fn build_sysex_set_ph_cal(slope: f32, offset: f32) -> Vec<u8> {
+    let mut sx = vec![0xF0, SYSEX_MFR, CMD_SET_PH_CAL];
+    sx.extend_from_slice(&encode_float(slope));
+    sx.extend_from_slice(&encode_float(offset));
+    sx.push(0xF7);
+    sx
+}
+
+pub fn build_sysex_get_ph_cal() -> Vec<u8> {
+    vec![0xF0, SYSEX_MFR, CMD_GET_PH_CAL, 0xF7]
+}