nah it really does work pretty good now, the hard part is working out

the electrode arrays themsevles now

cue/build.sh

@@ -20,7 +20,12 @@ render_svg() {
     if command -v rsvg-convert >/dev/null 2>&1; then
         rsvg-convert -w "$size" -h "$size" "$svg" -o "$out"
     elif command -v magick >/dev/null 2>&1; then
-        magick "$svg" -background none -resize "${size}x${size}" "$out"
+        # Compute DPI so SVG viewport rasterizes at target pixel size.
+        # Default 72 DPI renders the 83.25-unit viewport at 83px;
+        # scaling DPI proportionally renders at exact target dimensions.
+        local dpi=$(( (size * 72 + 82) / 83 ))
+        magick -background none -density "$dpi" "$svg" \
+            -resize "${size}x${size}" "PNG32:$out"
     else
         echo "Error: need rsvg-convert (librsvg) or magick (ImageMagick 7)"
         exit 1
@@ -32,7 +37,7 @@ case "$(uname -s)" in
         echo "==> Generating .icns"
         ICONSET=$(mktemp -d)/cue.iconset
         mkdir -p "$ICONSET"
-        for size in 16 32 64 128 256 512; do
+        for size in 16 32 128 256 512; do
             render_svg "$SVG" "$size" "$ICONSET/icon_${size}x${size}.png"
             double=$((size * 2))
             render_svg "$SVG" "$double" "$ICONSET/icon_${size}x${size}@2x.png"

cue/src/app.rs

@@ -708,27 +708,27 @@ impl App {
             Tab::Eis => row![
                 column![
                     text("Start Hz").size(12),
-                    text_input("1000", &self.freq_start).on_input(Message::FreqStartChanged).width(100),
+                    text_input("1000", &self.freq_start).on_input(Message::FreqStartChanged).width(90),
                 ].spacing(2),
                 column![
                     text("Stop Hz").size(12),
-                    text_input("200000", &self.freq_stop).on_input(Message::FreqStopChanged).width(100),
+                    text_input("200000", &self.freq_stop).on_input(Message::FreqStopChanged).width(90),
                 ].spacing(2),
                 column![
                     text("PPD").size(12),
-                    text_input("10", &self.ppd).on_input(Message::PpdChanged).width(60),
+                    text_input("10", &self.ppd).on_input(Message::PpdChanged).width(50),
                 ].spacing(2),
                 column![
                     text("RTIA").size(12),
-                    pick_list(Rtia::ALL, Some(self.rtia), Message::RtiaSelected),
+                    pick_list(Rtia::ALL, Some(self.rtia), Message::RtiaSelected).width(110),
                 ].spacing(2),
                 column![
                     text("RCAL").size(12),
-                    pick_list(Rcal::ALL, Some(self.rcal), Message::RcalSelected),
+                    pick_list(Rcal::ALL, Some(self.rcal), Message::RcalSelected).width(160),
                 ].spacing(2),
                 column![
                     text("Electrodes").size(12),
-                    pick_list(Electrode::ALL, Some(self.electrode), Message::ElectrodeSelected),
+                    pick_list(Electrode::ALL, Some(self.electrode), Message::ElectrodeSelected).width(170),
                 ].spacing(2),
                 button(text("Apply").size(13))
                     .style(style_apply())
@@ -739,7 +739,7 @@ impl App {
                     .padding([6, 20])
                     .on_press(Message::StartSweep),
             ]
-            .spacing(10)
+            .spacing(8)
             .align_y(iced::Alignment::End)
             .into(),
 
@@ -758,7 +758,7 @@ impl App {
                 ].spacing(2),
                 column![
                     text("RTIA").size(12),
-                    pick_list(LpRtia::ALL, Some(self.lsv_rtia), Message::LsvRtiaSelected),
+                    pick_list(LpRtia::ALL, Some(self.lsv_rtia), Message::LsvRtiaSelected).width(Length::Shrink),
                 ].spacing(2),
                 button(text("Start LSV").size(13))
                     .style(style_action())
@@ -784,7 +784,7 @@ impl App {
                 ].spacing(2),
                 column![
                     text("RTIA").size(12),
-                    pick_list(LpRtia::ALL, Some(self.amp_rtia), Message::AmpRtiaSelected),
+                    pick_list(LpRtia::ALL, Some(self.amp_rtia), Message::AmpRtiaSelected).width(Length::Shrink),
                 ].spacing(2),
                 if self.amp_running {
                     button(text("Stop").size(13))
@@ -829,7 +829,7 @@ impl App {
                 ].spacing(2),
                 column![
                     text("RTIA").size(12),
-                    pick_list(LpRtia::ALL, Some(self.cl_rtia), Message::ClRtiaSelected),
+                    pick_list(LpRtia::ALL, Some(self.cl_rtia), Message::ClRtiaSelected).width(Length::Shrink),
                 ].spacing(2),
                 button(text("Measure").size(13))
                     .style(style_action())

main/echem.c

@@ -161,6 +161,10 @@ static float read_current_ua(float rtia_ohms)
     uint32_t raw = AD5940_ReadAfeResult(AFERESULT_SINC2);
     int32_t code = (raw & (1UL << 15)) ? (int32_t)(raw | 0xFFFF0000UL) : (int32_t)raw;
 
+    /* clamp near ADC saturation to prevent sign-flip wrap artifact */
+    if (code > 32700) code = 32700;
+    if (code < -32700) code = -32700;
+
     /* I = V_tia / RTIA, V_tia = code * Vref / (PGA * 32768) */
     float v_tia = (float)code * 1.82f / (1.5f * 32768.0f);
     float i_a = v_tia / rtia_ohms;
@@ -245,6 +249,34 @@ static float read_voltage_mv(uint32_t muxp)
     return (float)code * 1820.0f / (1.5f * 32768.0f);
 }
 
+static void echem_shutdown_lp(void)
+{
+    LPLoopCfg_Type lp;
+    AD5940_StructInit(&lp, sizeof(lp));
+    lp.LpDacCfg.LpdacSel     = LPDAC0;
+    lp.LpDacCfg.LpDacSrc     = LPDACSRC_MMR;
+    lp.LpDacCfg.LpDacVzeroMux = LPDACVZERO_6BIT;
+    lp.LpDacCfg.LpDacVbiasMux = LPDACVBIAS_12BIT;
+    lp.LpDacCfg.LpDacSW      = 0;
+    lp.LpDacCfg.LpDacRef     = LPDACREF_2P5;
+    lp.LpDacCfg.PowerEn      = bFALSE;
+    lp.LpDacCfg.DataRst      = bFALSE;
+    lp.LpDacCfg.DacData6Bit  = 0;
+    lp.LpDacCfg.DacData12Bit = 0;
+    lp.LpAmpCfg.LpAmpSel    = LPAMP0;
+    lp.LpAmpCfg.LpAmpPwrMod = LPAMPPWR_NORM;
+    lp.LpAmpCfg.LpPaPwrEn   = bFALSE;
+    lp.LpAmpCfg.LpTiaPwrEn  = bFALSE;
+    lp.LpAmpCfg.LpTiaRf     = LPTIARF_OPEN;
+    lp.LpAmpCfg.LpTiaRload  = LPTIARLOAD_SHORT;
+    lp.LpAmpCfg.LpTiaRtia   = LPTIARTIA_OPEN;
+    lp.LpAmpCfg.LpTiaSW     = 0;
+    AD5940_LPLoopCfgS(&lp);
+
+    SWMatrixCfg_Type sw = { SWD_OPEN, SWP_OPEN, SWN_OPEN, SWT_OPEN };
+    AD5940_SWMatrixCfgS(&sw);
+}
+
 /* ---- public ---- */
 
 void echem_default_lsv(LSVConfig *cfg)
@@ -265,7 +297,33 @@ void echem_default_amp(AmpConfig *cfg)
     cfg->lp_rtia     = LP_RTIA_10K;
 }
 
-int echem_lsv(const LSVConfig *cfg, LSVPoint *out, uint32_t max_points)
+static void lsv_calc_step(const LSVConfig *cfg, uint32_t max_points,
+                          uint32_t *n_out, float *step_out)
+{
+    float v_range = cfg->v_stop - cfg->v_start;
+    uint32_t n_lsb = (uint32_t)(fabsf(v_range / VBIAS_LSB) + 0.5f);
+    uint32_t n_steps = n_lsb;
+    uint32_t step_mult = 1;
+    if (n_steps > max_points) {
+        step_mult = (n_lsb + max_points - 1) / max_points;
+        n_steps = (n_lsb + step_mult - 1) / step_mult;
+    }
+    if (n_steps < 2) n_steps = 2;
+    *n_out = n_steps;
+    *step_out = (v_range > 0) ? VBIAS_LSB * step_mult : -VBIAS_LSB * step_mult;
+}
+
+uint32_t echem_lsv_calc_steps(const LSVConfig *cfg, uint32_t max_points)
+{
+    float v_range = cfg->v_stop - cfg->v_start;
+    if (fabsf(v_range) < 0.001f) return 0;
+    uint32_t n;
+    float step;
+    lsv_calc_step(cfg, max_points, &n, &step);
+    return n;
+}
+
+int echem_lsv(const LSVConfig *cfg, LSVPoint *out, uint32_t max_points, lsv_point_cb_t cb)
 {
     if (cfg->lp_rtia >= LP_RTIA_COUNT) return 0;
     float rtia = lp_rtia_ohms[cfg->lp_rtia];
@@ -281,17 +339,9 @@ int echem_lsv(const LSVConfig *cfg, LSVPoint *out, uint32_t max_points)
     float v_range = cfg->v_stop - cfg->v_start;
     if (fabsf(v_range) < 0.001f) return 0;
 
-    /* compute steps to always cover full range within max_points */
+    uint32_t n_steps;
-    uint32_t n_lsb = (uint32_t)(fabsf(v_range / VBIAS_LSB) + 0.5f);
+    float step;
-    uint32_t n_steps = n_lsb;
+    lsv_calc_step(cfg, max_points, &n_steps, &step);
-    uint32_t step_mult = 1;
-    if (n_steps > max_points) {
-        step_mult = (n_lsb + max_points - 1) / max_points;
-        n_steps = (n_lsb + step_mult - 1) / step_mult;
-    }
-    if (n_steps < 2) n_steps = 2;
-
-    float step = (v_range > 0) ? VBIAS_LSB * step_mult : -VBIAS_LSB * step_mult;
 
     float delay_ms = fabsf(step / cfg->scan_rate) * 1000.0f;
     if (delay_ms < 1.0f) delay_ms = 1.0f;
@@ -312,13 +362,15 @@ int echem_lsv(const LSVConfig *cfg, LSVPoint *out, uint32_t max_points)
         out[i].i_ua = i_ua;
 
         printf("%10.1f  %10.3f\n", v_mv, i_ua);
+        if (cb) cb((uint16_t)i, v_mv, i_ua);
     }
 
+    echem_shutdown_lp();
     AD5940_AFECtrlS(AFECTRL_ALL, bFALSE);
     return (int)n_steps;
 }
 
-int echem_amp(const AmpConfig *cfg, AmpPoint *out, uint32_t max_points)
+int echem_amp(const AmpConfig *cfg, AmpPoint *out, uint32_t max_points, amp_point_cb_t cb)
 {
     if (cfg->lp_rtia >= LP_RTIA_COUNT) return 0;
     float rtia = lp_rtia_ohms[cfg->lp_rtia];
@@ -347,7 +399,6 @@ int echem_amp(const AmpConfig *cfg, AmpPoint *out, uint32_t max_points)
     uint32_t count = 0;
 
     for (uint32_t i = 0; i < max_samples; i++) {
-        /* check for stop command (non-blocking) */
         BleCommand cmd;
         if (ble_recv_command(&cmd, 0) == 0 && cmd.type == CMD_STOP_AMP)
             break;
@@ -360,10 +411,12 @@ int echem_amp(const AmpConfig *cfg, AmpPoint *out, uint32_t max_points)
         count++;
 
         printf("%10.1f  %10.3f\n", t_ms, i_ua);
+        if (cb) cb((uint16_t)i, t_ms, i_ua);
 
         vTaskDelay(interval);
     }
 
+    echem_shutdown_lp();
     AD5940_AFECtrlS(AFECTRL_ALL, bFALSE);
     return (int)count;
 }
@@ -383,7 +436,7 @@ void echem_default_cl(ClConfig *cfg)
 static uint32_t sample_phase(float v_mv, float t_dep_ms, float t_meas_ms,
                               uint8_t phase, float rtia_ohms,
                               ClPoint *out, uint32_t idx, uint32_t max_points,
-                              TickType_t t0, float *avg_out)
+                              TickType_t t0, float *avg_out, cl_point_cb_t cb)
 {
     AD5940_LPDAC0WriteS(mv_to_vbias_code(v_mv), VZERO_CODE);
 
@@ -405,6 +458,8 @@ static uint32_t sample_phase(float v_mv, float t_dep_ms, float t_meas_ms,
         out[idx].t_ms  = t_ms;
         out[idx].i_ua  = i_ua;
         out[idx].phase = phase;
+
+        if (cb) cb((uint16_t)idx, t_ms, i_ua, phase);
         idx++;
 
         sum += i_ua;
@@ -417,7 +472,8 @@ static uint32_t sample_phase(float v_mv, float t_dep_ms, float t_meas_ms,
     return idx;
 }
 
-int echem_chlorine(const ClConfig *cfg, ClPoint *out, uint32_t max_points, ClResult *result)
+int echem_chlorine(const ClConfig *cfg, ClPoint *out, uint32_t max_points,
+                   ClResult *result, cl_point_cb_t cb)
 {
     if (cfg->lp_rtia >= LP_RTIA_COUNT) return 0;
     float rtia = lp_rtia_ohms[cfg->lp_rtia];
@@ -434,15 +490,16 @@ int echem_chlorine(const ClConfig *cfg, ClPoint *out, uint32_t max_points, ClRes
     printf("Cl: free chlorine at %.0f mV\n", cfg->v_free);
     idx = sample_phase(cfg->v_free, cfg->t_dep_ms, cfg->t_meas_ms,
                         CL_PHASE_FREE, rtia, out, idx, max_points, t0,
-                        &result->i_free_ua);
+                        &result->i_free_ua, cb);
 
     printf("Cl: total chlorine at %.0f mV\n", cfg->v_total);
     idx = sample_phase(cfg->v_total, cfg->t_dep_ms, cfg->t_meas_ms,
                         CL_PHASE_TOTAL, rtia, out, idx, max_points, t0,
-                        &result->i_total_ua);
+                        &result->i_total_ua, cb);
 
     printf("Cl: free=%.3f uA, total=%.3f uA\n", result->i_free_ua, result->i_total_ua);
 
+    echem_shutdown_lp();
     AD5940_AFECtrlS(AFECTRL_ALL, bFALSE);
     return (int)idx;
 }
@@ -490,6 +547,7 @@ int echem_ph_ocp(const PhConfig *cfg, PhResult *result)
     printf("pH: SE0=%.1f mV, RE0=%.1f mV, OCP=%.1f mV, pH=%.2f\n",
            v_se0, v_re0, ocp, result->ph);
 
+    echem_shutdown_lp();
     AD5940_AFECtrlS(AFECTRL_ALL, bFALSE);
     return 0;
 }

main/echem.h

@@ -80,14 +80,19 @@ typedef struct {
     float temp_c;       /* temperature used */
 } PhResult;
 
+typedef int (*lsv_point_cb_t)(uint16_t idx, float v_mv, float i_ua);
+typedef int (*amp_point_cb_t)(uint16_t idx, float t_ms, float i_ua);
+typedef int (*cl_point_cb_t)(uint16_t idx, float t_ms, float i_ua, uint8_t phase);
+
 void echem_default_lsv(LSVConfig *cfg);
 void echem_default_amp(AmpConfig *cfg);
 void echem_default_cl(ClConfig *cfg);
 void echem_default_ph(PhConfig *cfg);
 
-int echem_lsv(const LSVConfig *cfg, LSVPoint *out, uint32_t max_points);
+uint32_t echem_lsv_calc_steps(const LSVConfig *cfg, uint32_t max_points);
-int echem_amp(const AmpConfig *cfg, AmpPoint *out, uint32_t max_points);
+int echem_lsv(const LSVConfig *cfg, LSVPoint *out, uint32_t max_points, lsv_point_cb_t cb);
-int echem_chlorine(const ClConfig *cfg, ClPoint *out, uint32_t max_points, ClResult *result);
+int echem_amp(const AmpConfig *cfg, AmpPoint *out, uint32_t max_points, amp_point_cb_t cb);
+int echem_chlorine(const ClConfig *cfg, ClPoint *out, uint32_t max_points, ClResult *result, cl_point_cb_t cb);
 int echem_ph_ocp(const PhConfig *cfg, PhResult *result);
 
 #endif

main/eis.c

@@ -410,7 +410,7 @@ int eis_measure_point(float freq_hz, EISPoint *out)
     return 0;
 }
 
-int eis_sweep(EISPoint *out, uint32_t max_points)
+int eis_sweep(EISPoint *out, uint32_t max_points, eis_point_cb_t cb)
 {
     uint32_t n = eis_calc_num_points(&ctx.cfg);
     if (n > max_points) n = max_points;
@@ -435,6 +435,7 @@ int eis_sweep(EISPoint *out, uint32_t max_points)
     printf("%10.1f  %12.2f  %10.2f  %12.2f  %12.2f  %6.2f%%\n",
            out[0].freq_hz, out[0].mag_ohms, out[0].phase_deg,
            out[0].z_real, out[0].z_imag, out[0].pct_err);
+    if (cb) cb(0, &out[0]);
 
     for (uint32_t i = 1; i < n; i++) {
         float freq;
@@ -443,6 +444,7 @@ int eis_sweep(EISPoint *out, uint32_t max_points)
         printf("%10.1f  %12.2f  %10.2f  %12.2f  %12.2f  %6.2f%%\n",
                out[i].freq_hz, out[i].mag_ohms, out[i].phase_deg,
                out[i].z_real, out[i].z_imag, out[i].pct_err);
+        if (cb) cb((uint16_t)i, &out[i]);
     }
 
     /* guard: throwaway at stop frequency to cap the sweep cleanly */

main/eis.h

@@ -49,11 +49,13 @@ typedef struct {
     float pct_err;
 } EISPoint;
 
+typedef int (*eis_point_cb_t)(uint16_t idx, const EISPoint *pt);
+
 void eis_default_config(EISConfig *cfg);
 void eis_init(const EISConfig *cfg);
 void eis_reconfigure(const EISConfig *cfg);
 int  eis_measure_point(float freq_hz, EISPoint *out);
-int  eis_sweep(EISPoint *out, uint32_t max_points);
+int  eis_sweep(EISPoint *out, uint32_t max_points, eis_point_cb_t cb);
 uint32_t eis_calc_num_points(const EISConfig *cfg);
 
 #endif

main/eis4.c

@@ -22,14 +22,9 @@ static void do_sweep(void)
     eis_init(&cfg);
 
     uint32_t n = eis_calc_num_points(&cfg);
-    int got = eis_sweep(results, n);
+    ble_send_sweep_start(n, cfg.freq_start_hz, cfg.freq_stop_hz);
+    int got = eis_sweep(results, n, ble_send_eis_point);
     printf("Sweep complete: %d points\n", got);
-
-    ble_send_sweep_start(got, cfg.freq_start_hz, cfg.freq_stop_hz);
-    for (int i = 0; i < got; i++) {
-        ble_send_eis_point(i, &results[i]);
-        vTaskDelay(pdMS_TO_TICKS(10));
-    }
     ble_send_sweep_end();
 }
 
@@ -124,14 +119,10 @@ void app_main(void)
             printf("LSV: %.0f-%.0f mV, %.0f mV/s, rtia=%u\n",
                    lsv_cfg.v_start, lsv_cfg.v_stop, lsv_cfg.scan_rate, lsv_cfg.lp_rtia);
 
-            int got = echem_lsv(&lsv_cfg, lsv_results, ECHEM_MAX_POINTS);
+            uint32_t n = echem_lsv_calc_steps(&lsv_cfg, ECHEM_MAX_POINTS);
+            ble_send_lsv_start(n, lsv_cfg.v_start, lsv_cfg.v_stop);
+            int got = echem_lsv(&lsv_cfg, lsv_results, ECHEM_MAX_POINTS, ble_send_lsv_point);
             printf("LSV complete: %d points\n", got);
-
-            ble_send_lsv_start(got, lsv_cfg.v_start, lsv_cfg.v_stop);
-            for (int i = 0; i < got; i++) {
-                ble_send_lsv_point(i, lsv_results[i].v_mv, lsv_results[i].i_ua);
-                vTaskDelay(pdMS_TO_TICKS(10));
-            }
             ble_send_lsv_end();
             break;
         }
@@ -146,14 +137,8 @@ void app_main(void)
                    amp_cfg.v_hold, amp_cfg.interval_ms, amp_cfg.duration_s);
 
             ble_send_amp_start(amp_cfg.v_hold);
-
+            int got = echem_amp(&amp_cfg, amp_results, ECHEM_MAX_POINTS, ble_send_amp_point);
-            int got = echem_amp(&amp_cfg, amp_results, ECHEM_MAX_POINTS);
             printf("Amp complete: %d points\n", got);
-
-            for (int i = 0; i < got; i++) {
-                ble_send_amp_point(i, amp_results[i].t_ms, amp_results[i].i_ua);
-                vTaskDelay(pdMS_TO_TICKS(10));
-            }
             ble_send_amp_end();
             break;
         }
@@ -187,16 +172,14 @@ void app_main(void)
             cl_cfg.t_meas_ms = cmd.cl.t_meas_ms;
             cl_cfg.lp_rtia   = cmd.cl.lp_rtia;
 
+            uint32_t n_per = (uint32_t)(cl_cfg.t_meas_ms / 50.0f + 0.5f);
+            if (n_per < 2) n_per = 2;
+            ble_send_cl_start(2 * n_per);
             ClResult cl_result;
-            int got = echem_chlorine(&cl_cfg, cl_results, ECHEM_MAX_POINTS, &cl_result);
+            int got = echem_chlorine(&cl_cfg, cl_results, ECHEM_MAX_POINTS,
+                                      &cl_result, ble_send_cl_point);
             printf("Cl complete: %d points, free=%.3f uA, total=%.3f uA\n",
                    got, cl_result.i_free_ua, cl_result.i_total_ua);
-
-            ble_send_cl_start(got);
-            for (int i = 0; i < got; i++) {
-                ble_send_cl_point(i, cl_results[i].t_ms, cl_results[i].i_ua, cl_results[i].phase);
-                vTaskDelay(pdMS_TO_TICKS(10));
-            }
             ble_send_cl_result(cl_result.i_free_ua, cl_result.i_total_ua);
             ble_send_cl_end();
             break;