Add shade profiles, 2D V×I sweep, meter format toggle, ON/OFF indicators, and GUI console

- Shade profile: CSV-driven irradiance/voltage sequences with load control
  (bench.run_shade_profile, CLI shade-profile command, GUI profile panel)
- 2D sweep: voltage × load current efficiency map with live graph updates
  (bench.sweep_vi, CLI sweep-vi command, GUI sweep panel with background thread)
- GUI: meter format selector (scientific/normal), supply/load ON/OFF indicators,
  console log with stdout redirect and color-coded messages
- Sample profiles: cloud_pass, partial_shade, intermittent_clouds

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -5,3 +5,4 @@ dist/
 build/
 .venv/
 *.csv
+!samples/*.csv

samples/cloud_pass.csv

@@ -0,0 +1,11 @@
+time,voltage,current_limit,load_mode,load_value
+0,75,10.0,CC,3.0
+10,75,8.0,CC,3.0
+20,75,6.0,CC,3.0
+30,75,4.0,CC,2.0
+40,75,2.0,CC,1.0
+50,75,2.0,CC,1.0
+60,75,4.0,CC,2.0
+70,75,6.0,CC,3.0
+80,75,8.0,CC,3.0
+90,75,10.0,CC,3.0

samples/intermittent_clouds.csv

@@ -0,0 +1,15 @@
+time,voltage,current_limit,load_mode,load_value
+0,75,10.0,CC,3.0
+10,75,10.0,CC,3.0
+15,75,4.0,CC,2.0
+25,75,4.0,CC,2.0
+30,75,10.0,CC,3.0
+40,75,10.0,CC,3.0
+45,75,6.0,CC,2.5
+55,75,6.0,CC,2.5
+60,75,10.0,CC,3.0
+70,75,10.0,CC,3.0
+75,75,2.0,CC,1.0
+90,75,2.0,CC,1.0
+95,75,10.0,CC,3.0
+110,75,10.0,CC,3.0

samples/partial_shade.csv

@@ -0,0 +1,11 @@
+time,voltage,current_limit,load_mode,load_value
+0,75,10.0,CC,3.0
+15,75,10.0,CC,3.0
+30,75,7.0,CC,3.0
+45,65,5.0,CC,2.5
+60,55,3.0,CC,2.0
+75,55,3.0,CC,2.0
+90,65,5.0,CC,2.5
+105,75,7.0,CC,3.0
+120,75,10.0,CC,3.0
+135,75,10.0,CC,3.0

testbench/bench.py

@@ -417,6 +417,251 @@ class MPPTTestbench:
 
         return results
 
+    # ── Load value helper ─────────────────────────────────────────────
+
+    def _apply_load_value(self, mode: str, value: float) -> None:
+        """Set the load setpoint for the given mode."""
+        if mode == "CC":
+            self.load.set_cc_current(value)
+        elif mode == "CR":
+            self.load.set_cr_resistance(value)
+        elif mode == "CV":
+            self.load.set_cv_voltage(value)
+        elif mode == "CP":
+            self.load.set_cp_power(value)
+
+    # ── Shade Profile ────────────────────────────────────────────────
+
+    @staticmethod
+    def load_shade_profile(path: str) -> list[dict]:
+        """Load a shade profile CSV.
+
+        Required columns: time, voltage, current_limit
+        Optional columns: load_mode, load_value
+
+        Returns:
+            Sorted list of step dicts.
+        """
+        import csv as _csv
+
+        steps = []
+        with open(path, newline="") as f:
+            reader = _csv.DictReader(f)
+            for row in reader:
+                step = {
+                    "time": float(row["time"]),
+                    "voltage": float(row["voltage"]),
+                    "current_limit": float(row["current_limit"]),
+                }
+                if "load_mode" in row and row["load_mode"].strip():
+                    step["load_mode"] = row["load_mode"].strip().upper()
+                if "load_value" in row and row["load_value"].strip():
+                    step["load_value"] = float(row["load_value"])
+                steps.append(step)
+        steps.sort(key=lambda s: s["time"])
+        return steps
+
+    def run_shade_profile(
+        self,
+        steps: list[dict],
+        settle_time: float = 2.0,
+    ) -> list[SweepPoint]:
+        """Run a shade / irradiance profile sequence.
+
+        Steps through the profile, applying voltage/current/load settings
+        at the scheduled times, recording a measurement at each step.
+
+        Args:
+            steps: Profile steps from :meth:`load_shade_profile`.
+            settle_time: Seconds to wait after applying each step before
+                         recording a measurement.
+
+        Returns:
+            List of SweepPoint measurements, one per step.
+        """
+        if not steps:
+            return []
+
+        # Apply first step and turn outputs on
+        first = steps[0]
+        self.supply.set_current(first["current_limit"])
+        self.supply.set_voltage(first["voltage"])
+        self.supply.output_on()
+
+        if "load_mode" in first:
+            self.load.set_mode(first["load_mode"])
+        if "load_value" in first:
+            self._apply_load_value(
+                first.get("load_mode", "CC"), first["load_value"]
+            )
+        self.load.load_on()
+
+        results: list[SweepPoint] = []
+        t0 = time.time()
+
+        try:
+            for i, step in enumerate(steps):
+                # Wait until scheduled time, keepalive supply while waiting
+                target = t0 + step["time"]
+                while True:
+                    remaining = target - time.time()
+                    if remaining <= 0:
+                        break
+                    if remaining > 2.0:
+                        try:
+                            self.supply.measure_voltage()
+                        except Exception:
+                            pass
+                        time.sleep(min(2.0, remaining))
+                    else:
+                        time.sleep(remaining)
+
+                # Apply settings
+                self.supply.set_current(step["current_limit"])
+                self.supply.set_voltage(step["voltage"])
+
+                if "load_mode" in step:
+                    self.load.set_mode(step["load_mode"])
+                if "load_value" in step:
+                    self._apply_load_value(
+                        step.get("load_mode", "CC"), step["load_value"]
+                    )
+
+                time.sleep(settle_time)
+
+                # Record
+                load_val = step.get("load_value", 0.0) or 0.0
+                point = self._record_point(
+                    step["voltage"], step["current_limit"], load_val
+                )
+                results.append(point)
+                elapsed = time.time() - t0
+                print(
+                    f"  [{i + 1}/{len(steps)}] t={elapsed:6.1f}s  "
+                    f"V={step['voltage']:.1f}V  I_lim={step['current_limit']:.1f}A  "
+                    f"P_in={point.input_power:8.2f}W  "
+                    f"P_out={point.output_power:8.2f}W  "
+                    f"EFF={point.efficiency:6.2f}%"
+                )
+        finally:
+            self.load.load_off()
+            self.supply.set_voltage(IDLE_VOLTAGE)
+            print(
+                f"\n  Profile complete. Load OFF. "
+                f"Supply returning to {IDLE_VOLTAGE:.0f}V (output stays ON)"
+            )
+
+        return results
+
+    # ── 2D Voltage × Current Sweep ─────────────────────────────────────
+
+    def sweep_vi(
+        self,
+        v_start: float,
+        v_stop: float,
+        v_step: float,
+        i_start: float,
+        i_stop: float,
+        i_step: float,
+        current_limit: float,
+        settle_time: float = 2.0,
+    ) -> list[SweepPoint]:
+        """2D sweep: voltage (outer) × load current (inner).
+
+        At each supply voltage, sweeps the load current through the full
+        range, recording efficiency at every (V, I) combination.  Produces
+        a complete efficiency map of the DUT.
+
+        After the sweep the load turns OFF and the supply returns to
+        IDLE_VOLTAGE (75 V, output stays ON).
+
+        Args:
+            v_start:  Starting supply voltage (V).
+            v_stop:   Final supply voltage (V).
+            v_step:   Voltage step size (V).  Sign is auto-corrected.
+            i_start:  Starting load current (A).
+            i_stop:   Final load current (A).
+            i_step:   Current step size (A).  Sign is auto-corrected.
+            current_limit: Supply current limit (A) for the entire sweep.
+            settle_time: Seconds to wait after each setpoint change.
+        """
+        if v_step == 0:
+            raise ValueError("v_step cannot be zero")
+        if i_step == 0:
+            raise ValueError("i_step cannot be zero")
+
+        # Auto-correct step directions
+        if v_start < v_stop and v_step < 0:
+            v_step = -v_step
+        elif v_start > v_stop and v_step > 0:
+            v_step = -v_step
+
+        if i_start < i_stop and i_step < 0:
+            i_step = -i_step
+        elif i_start > i_stop and i_step > 0:
+            i_step = -i_step
+
+        # Count steps for progress display
+        v_count = int(abs(v_stop - v_start) / abs(v_step)) + 1
+        i_count = int(abs(i_stop - i_start) / abs(i_step)) + 1
+        total = v_count * i_count
+        print(f"  Grid: {v_count} voltage × {i_count} current = {total} points")
+
+        self.supply.set_current(current_limit)
+        self.supply.output_on()
+        self.load.set_mode("CC")
+        self.load.set_cc_current(i_start)
+        self.load.load_on()
+
+        results: list[SweepPoint] = []
+        n = 0
+        v = v_start
+
+        try:
+            while True:
+                if v_step > 0 and v > v_stop + v_step / 2:
+                    break
+                if v_step < 0 and v < v_stop + v_step / 2:
+                    break
+
+                self.supply.set_voltage(v)
+                i = i_start
+
+                while True:
+                    if i_step > 0 and i > i_stop + i_step / 2:
+                        break
+                    if i_step < 0 and i < i_stop + i_step / 2:
+                        break
+
+                    self.load.set_cc_current(i)
+                    time.sleep(settle_time)
+
+                    point = self._record_point(v, current_limit, load_setpoint=i)
+                    results.append(point)
+                    n += 1
+
+                    print(
+                        f"  [{n:>4d}/{total}] "
+                        f"V={v:6.1f}V  I_load={i:6.2f}A  "
+                        f"P_in={point.input_power:8.2f}W  "
+                        f"P_out={point.output_power:8.2f}W  "
+                        f"EFF={point.efficiency:6.2f}%"
+                    )
+
+                    i += i_step
+
+                v += v_step
+
+        finally:
+            self.load.load_off()
+            self.supply.set_voltage(IDLE_VOLTAGE)
+            print(
+                f"\n  Load OFF. Supply returning to {IDLE_VOLTAGE:.0f}V "
+                f"(output stays ON)"
+            )
+
+        return results
+
     # ── Efficiency at fixed operating point ───────────────────────────
 
     def measure_efficiency(

testbench/cli.py

@@ -438,6 +438,55 @@ def cmd_efficiency(bench: MPPTTestbench, args: argparse.Namespace) -> None:
     print(f"Average efficiency:   {result['avg_efficiency']:.2f} %")
 
 
+def cmd_sweep_vi(bench: MPPTTestbench, args: argparse.Namespace) -> None:
+    """Run a 2D voltage × load current sweep."""
+    print(
+        f"2D sweep: V={args.v_start:.1f}-{args.v_stop:.1f}V (step {args.v_step:.1f}), "
+        f"I_load={args.i_start:.2f}-{args.i_stop:.2f}A (step {args.i_step:.2f}), "
+        f"I_limit={args.current_limit:.1f}A, settle={args.settle:.1f}s"
+    )
+    print()
+
+    results = bench.sweep_vi(
+        v_start=args.v_start,
+        v_stop=args.v_stop,
+        v_step=args.v_step,
+        i_start=args.i_start,
+        i_stop=args.i_stop,
+        i_step=args.i_step,
+        current_limit=args.current_limit,
+        settle_time=args.settle,
+    )
+
+    _write_sweep_csv(results, args.output)
+    _print_sweep_summary(results)
+
+
+def cmd_shade_profile(bench: MPPTTestbench, args: argparse.Namespace) -> None:
+    """Run a shade / irradiance profile from a CSV file."""
+    steps = MPPTTestbench.load_shade_profile(args.profile)
+    duration = steps[-1]["time"] if steps else 0
+
+    print(f"Shade profile: {args.profile}")
+    print(f"  {len(steps)} steps over {duration:.0f}s, settle={args.settle:.1f}s")
+
+    # Show what modes/values are used
+    modes = {s.get("load_mode", "?") for s in steps}
+    voltages = [s["voltage"] for s in steps]
+    currents = [s["current_limit"] for s in steps]
+    print(
+        f"  Voltage: {min(voltages):.1f} - {max(voltages):.1f}V, "
+        f"I_limit: {min(currents):.1f} - {max(currents):.1f}A, "
+        f"Load modes: {', '.join(sorted(modes))}"
+    )
+    print()
+
+    results = bench.run_shade_profile(steps, settle_time=args.settle)
+
+    _write_sweep_csv(results, args.output)
+    _print_sweep_summary(results)
+
+
 def cmd_supply(bench: MPPTTestbench, args: argparse.Namespace) -> None:
     """Control the DC supply directly."""
     if args.action == "on":
@@ -515,6 +564,8 @@ examples:
   %(prog)s sweep --v-start 10 --v-stop 50 --v-step 1 --current-limit 10 -o sweep.csv
   %(prog)s sweep-load --voltage 75 --current-limit 10 --i-start 1 --i-stop 20 --i-step 1 -o load.csv
   %(prog)s efficiency --voltage 36 --current-limit 10 --samples 10
+  %(prog)s sweep-vi --v-start 35 --v-stop 100 --v-step 5 --i-start 0.5 --i-stop 30 --i-step 1 --current-limit 35 -o map.csv
+  %(prog)s shade-profile --profile cloud_pass.csv --settle 2.0 -o shade_results.csv
   %(prog)s supply set --voltage 24 --current 10
   %(prog)s supply on
   %(prog)s load set --mode CC --value 5.0
@@ -599,6 +650,24 @@ examples:
     p_eff.add_argument("--load-mode", choices=["CC", "CR", "CV", "CP"])
     p_eff.add_argument("--load-value", type=float)
 
+    # sweep-vi (2D)
+    p_svi = sub.add_parser("sweep-vi", help="2D voltage × load current sweep (efficiency map)")
+    p_svi.add_argument("--v-start", type=float, required=True, help="Start voltage (V)")
+    p_svi.add_argument("--v-stop", type=float, required=True, help="Stop voltage (V)")
+    p_svi.add_argument("--v-step", type=float, required=True, help="Voltage step (V)")
+    p_svi.add_argument("--i-start", type=float, required=True, help="Start load current (A)")
+    p_svi.add_argument("--i-stop", type=float, required=True, help="Stop load current (A)")
+    p_svi.add_argument("--i-step", type=float, required=True, help="Current step (A)")
+    p_svi.add_argument("--current-limit", type=float, required=True, help="Supply current limit (A)")
+    p_svi.add_argument("--settle", type=float, default=2.0, help="Settle time per step (s)")
+    p_svi.add_argument("-o", "--output", help="CSV output file")
+
+    # shade-profile
+    p_shade = sub.add_parser("shade-profile", help="Run a shade/irradiance profile from CSV")
+    p_shade.add_argument("--profile", required=True, help="Profile CSV file (time,voltage,current_limit,...)")
+    p_shade.add_argument("--settle", type=float, default=2.0, help="Settle time per step (s)")
+    p_shade.add_argument("-o", "--output", help="CSV output file for results")
+
     # supply (direct control)
     p_sup = sub.add_parser("supply", help="Direct supply control")
     p_sup_sub = p_sup.add_subparsers(dest="action", required=True)
@@ -631,6 +700,8 @@ examples:
         "sweep": cmd_sweep,
         "sweep-load": cmd_sweep_load,
         "efficiency": cmd_efficiency,
+        "sweep-vi": cmd_sweep_vi,
+        "shade-profile": cmd_shade_profile,
         "supply": cmd_supply,
         "load": cmd_load,
         "safe-off": cmd_safe_off,

testbench/gui.py

@@ -6,7 +6,9 @@ Tkinter app with embedded matplotlib graphs and threaded instrument I/O.
 from __future__ import annotations
 
 import csv
+import queue
 import sys
+import threading
 import time
 import tkinter as tk
 from tkinter import ttk, messagebox, filedialog
@@ -47,6 +49,30 @@ def _clean(val: float) -> float:
     return float("nan") if abs(val) >= ERROR_THRESHOLD else val
 
 
+class _ConsoleRedirector:
+    """Redirects stdout writes to the GUI console widget."""
+
+    def __init__(self, gui: "TestbenchGUI") -> None:
+        self._gui = gui
+        self._orig = sys.stdout
+        self._buf = ""
+
+    def write(self, text: str) -> None:
+        if self._orig:
+            self._orig.write(text)
+        # Buffer partial lines, flush on newline
+        self._buf += text
+        while "\n" in self._buf:
+            line, self._buf = self._buf.split("\n", 1)
+            line = line.strip()
+            if line:
+                self._gui._console(line)
+
+    def flush(self) -> None:
+        if self._orig:
+            self._orig.flush()
+
+
 class TestbenchGUI(tk.Tk):
     """Main GUI window."""
 
@@ -77,6 +103,9 @@ class TestbenchGUI(tk.Tk):
             ]
         }
 
+        self._meter_fmt_sci = True  # True=scientific, False=normal
+        self._sweep_data_queue: queue.Queue = queue.Queue(maxsize=100)
+
         self._build_ui()
         self.protocol("WM_DELETE_WINDOW", self._on_close)
 
@@ -99,14 +128,21 @@ class TestbenchGUI(tk.Tk):
         self._build_supply_controls(left_col0)
         self._build_load_controls(left_col0)
         self._build_logging_controls(left_col0)
+        self._build_profile_controls(left_col0)
         # Column 1: Meter
         left_col1 = ttk.Frame(left_outer)
         left_col1.grid(row=0, column=1, sticky="nsew", padx=(2, 0))
         self._build_meter_readout(left_col1)
-        # Right panel (graphs)
-        right_frame = ttk.Frame(content)
-        content.add(right_frame, weight=1)
-        self._build_graphs(right_frame)
+        self._build_sweep_vi_controls(left_col1)
+        # Right panel: graphs + console
+        right_pane = ttk.PanedWindow(content, orient=tk.VERTICAL)
+        content.add(right_pane, weight=1)
+        graph_frame = ttk.Frame(right_pane)
+        right_pane.add(graph_frame, weight=3)
+        self._build_graphs(graph_frame)
+        console_frame = ttk.Frame(right_pane)
+        right_pane.add(console_frame, weight=1)
+        self._build_console(console_frame)
         # Status bar
         self._build_status_bar()
 
@@ -217,6 +253,11 @@ class TestbenchGUI(tk.Tk):
         self._sup_i_label.pack(anchor=tk.W)
         self._sup_p_label = ttk.Label(readout, text="P: ---", font=("Consolas", 11))
         self._sup_p_label.pack(anchor=tk.W)
+        self._sup_state_label = tk.Label(
+            readout, text="OUTPUT: ---", font=("Consolas", 11, "bold"),
+            fg="#888888",
+        )
+        self._sup_state_label.pack(anchor=tk.W, pady=(4, 0))
 
     def _build_load_controls(self, parent) -> None:
         frame = ttk.LabelFrame(parent, text="DC Load (Prodigit 3366G)", padding=8)
@@ -277,6 +318,11 @@ class TestbenchGUI(tk.Tk):
         self._load_i_label.pack(anchor=tk.W)
         self._load_p_label = ttk.Label(readout, text="P: ---", font=("Consolas", 11))
         self._load_p_label.pack(anchor=tk.W)
+        self._load_state_label = tk.Label(
+            readout, text="LOAD: ---", font=("Consolas", 11, "bold"),
+            fg="#888888",
+        )
+        self._load_state_label.pack(anchor=tk.W, pady=(4, 0))
 
     def _build_meter_readout(self, parent) -> None:
         frame = ttk.LabelFrame(parent, text="Power Analyzer (HIOKI 3193-10)", padding=8)
@@ -324,6 +370,17 @@ class TestbenchGUI(tk.Tk):
         ttk.Button(row, text="Set", width=4,
                    command=lambda: self._send(Cmd.SET_COUPLING, 6, self._ch6_coupling.get())).pack(side=tk.LEFT, padx=2)
 
+        # Format selector
+        fmt_row = ttk.Frame(frame)
+        fmt_row.pack(fill=tk.X, pady=2)
+        ttk.Label(fmt_row, text="Format:", width=10).pack(side=tk.LEFT)
+        self._meter_fmt_combo = ttk.Combobox(
+            fmt_row, values=["Scientific", "Normal"], width=10, state="readonly"
+        )
+        self._meter_fmt_combo.set("Scientific")
+        self._meter_fmt_combo.pack(side=tk.LEFT, padx=2)
+        self._meter_fmt_combo.bind("<<ComboboxSelected>>", self._on_meter_fmt_change)
+
         # Input side
         input_frame = ttk.LabelFrame(frame, text="Input (Ch5 - Solar)", padding=4)
         input_frame.pack(fill=tk.X, pady=2)
@@ -372,6 +429,102 @@ class TestbenchGUI(tk.Tk):
         self._log_status = ttk.Label(frame, text="Not logging", font=("Consolas", 9))
         self._log_status.pack(anchor=tk.W, pady=2)
 
+    def _build_profile_controls(self, parent) -> None:
+        frame = ttk.LabelFrame(parent, text="Shade Profile", padding=8)
+        frame.pack(fill=tk.X, padx=4, pady=4)
+
+        row = ttk.Frame(frame)
+        row.pack(fill=tk.X, pady=2)
+        self._profile_path_label = ttk.Label(row, text="No file selected", font=("Consolas", 9))
+        self._profile_path_label.pack(side=tk.LEFT, fill=tk.X, expand=True)
+        ttk.Button(row, text="Browse", command=self._browse_profile).pack(side=tk.RIGHT, padx=2)
+
+        row = ttk.Frame(frame)
+        row.pack(fill=tk.X, pady=2)
+        ttk.Label(row, text="Settle (s):", width=12).pack(side=tk.LEFT)
+        self._profile_settle = ttk.Entry(row, width=6)
+        self._profile_settle.insert(0, "2.0")
+        self._profile_settle.pack(side=tk.LEFT, padx=2)
+
+        row = ttk.Frame(frame)
+        row.pack(fill=tk.X, pady=2)
+        self._btn_profile_run = ttk.Button(row, text="Run Profile", command=self._run_profile)
+        self._btn_profile_run.pack(side=tk.LEFT, padx=2)
+        self._btn_profile_stop = ttk.Button(row, text="Stop", command=self._stop_profile, state=tk.DISABLED)
+        self._btn_profile_stop.pack(side=tk.LEFT, padx=2)
+
+        self._profile_status = ttk.Label(frame, text="Idle", font=("Consolas", 9))
+        self._profile_status.pack(anchor=tk.W, pady=2)
+
+        self._profile_steps: list[dict] = []
+        self._profile_index = 0
+        self._profile_running = False
+        self._profile_t0 = 0.0
+        self._profile_after_id = None
+
+    def _build_sweep_vi_controls(self, parent) -> None:
+        frame = ttk.LabelFrame(parent, text="2D Sweep (V × I)", padding=8)
+        frame.pack(fill=tk.X, padx=4, pady=4)
+
+        # Voltage range
+        row = ttk.Frame(frame)
+        row.pack(fill=tk.X, pady=1)
+        ttk.Label(row, text="V start:", width=10).pack(side=tk.LEFT)
+        self._svi_v_start = ttk.Entry(row, width=7)
+        self._svi_v_start.insert(0, "35")
+        self._svi_v_start.pack(side=tk.LEFT, padx=2)
+        ttk.Label(row, text="stop:").pack(side=tk.LEFT)
+        self._svi_v_stop = ttk.Entry(row, width=7)
+        self._svi_v_stop.insert(0, "100")
+        self._svi_v_stop.pack(side=tk.LEFT, padx=2)
+        ttk.Label(row, text="step:").pack(side=tk.LEFT)
+        self._svi_v_step = ttk.Entry(row, width=5)
+        self._svi_v_step.insert(0, "5")
+        self._svi_v_step.pack(side=tk.LEFT, padx=2)
+
+        # Current range
+        row = ttk.Frame(frame)
+        row.pack(fill=tk.X, pady=1)
+        ttk.Label(row, text="I start:", width=10).pack(side=tk.LEFT)
+        self._svi_i_start = ttk.Entry(row, width=7)
+        self._svi_i_start.insert(0, "0.5")
+        self._svi_i_start.pack(side=tk.LEFT, padx=2)
+        ttk.Label(row, text="stop:").pack(side=tk.LEFT)
+        self._svi_i_stop = ttk.Entry(row, width=7)
+        self._svi_i_stop.insert(0, "30")
+        self._svi_i_stop.pack(side=tk.LEFT, padx=2)
+        ttk.Label(row, text="step:").pack(side=tk.LEFT)
+        self._svi_i_step = ttk.Entry(row, width=5)
+        self._svi_i_step.insert(0, "1")
+        self._svi_i_step.pack(side=tk.LEFT, padx=2)
+
+        # Supply current limit + settle
+        row = ttk.Frame(frame)
+        row.pack(fill=tk.X, pady=1)
+        ttk.Label(row, text="I limit:", width=10).pack(side=tk.LEFT)
+        self._svi_ilimit = ttk.Entry(row, width=7)
+        self._svi_ilimit.insert(0, "35")
+        self._svi_ilimit.pack(side=tk.LEFT, padx=2)
+        ttk.Label(row, text="settle:").pack(side=tk.LEFT)
+        self._svi_settle = ttk.Entry(row, width=5)
+        self._svi_settle.insert(0, "2.0")
+        self._svi_settle.pack(side=tk.LEFT, padx=2)
+        ttk.Label(row, text="s").pack(side=tk.LEFT)
+
+        # Run / Stop
+        row = ttk.Frame(frame)
+        row.pack(fill=tk.X, pady=2)
+        self._btn_svi_run = ttk.Button(row, text="Run Sweep", command=self._run_sweep_vi)
+        self._btn_svi_run.pack(side=tk.LEFT, padx=2)
+        self._btn_svi_stop = ttk.Button(row, text="Stop", command=self._stop_sweep_vi, state=tk.DISABLED)
+        self._btn_svi_stop.pack(side=tk.LEFT, padx=2)
+
+        self._svi_status = ttk.Label(frame, text="Idle", font=("Consolas", 9))
+        self._svi_status.pack(anchor=tk.W, pady=2)
+
+        self._svi_thread = None
+        self._svi_stop_event = None
+
     def _build_graphs(self, parent) -> None:
         self._fig = Figure(figsize=(10, 8), dpi=100)
         self._fig.suptitle("MPPT Testbench Live", fontsize=12, fontweight="bold")
@@ -422,6 +575,52 @@ class TestbenchGUI(tk.Tk):
         toolbar = NavigationToolbar2Tk(self._canvas, parent)
         toolbar.update()
 
+    def _build_console(self, parent) -> None:
+        frame = ttk.LabelFrame(parent, text="Console", padding=4)
+        frame.pack(fill=tk.BOTH, expand=True, padx=0, pady=0)
+
+        self._console_text = tk.Text(
+            frame, height=8, font=("Consolas", 9),
+            wrap=tk.WORD, state=tk.DISABLED,
+            bg="#1e1e1e", fg="#cccccc", insertbackground="#cccccc",
+        )
+        scrollbar = ttk.Scrollbar(frame, orient=tk.VERTICAL, command=self._console_text.yview)
+        self._console_text.config(yscrollcommand=scrollbar.set)
+        scrollbar.pack(side=tk.RIGHT, fill=tk.Y)
+        self._console_text.pack(side=tk.LEFT, fill=tk.BOTH, expand=True)
+
+        # Tag for error messages
+        self._console_text.tag_configure("error", foreground="#ff6b6b")
+        self._console_text.tag_configure("success", foreground="#69db7c")
+        self._console_text.tag_configure("warn", foreground="#ffd43b")
+
+        # Redirect stdout to console
+        self._orig_stdout = sys.stdout
+        sys.stdout = _ConsoleRedirector(self)
+
+    def _console(self, msg: str, tag: str = "") -> None:
+        """Append a message to the console log. Thread-safe."""
+        ts = time.strftime("%H:%M:%S")
+        line = f"[{ts}] {msg}\n"
+
+        def _append():
+            self._console_text.config(state=tk.NORMAL)
+            if tag:
+                self._console_text.insert(tk.END, line, tag)
+            else:
+                self._console_text.insert(tk.END, line)
+            self._console_text.see(tk.END)
+            self._console_text.config(state=tk.DISABLED)
+
+        # If called from a non-main thread, schedule on main thread
+        try:
+            if threading.current_thread() is threading.main_thread():
+                _append()
+            else:
+                self.after(0, _append)
+        except RuntimeError:
+            pass
+
     def _build_status_bar(self) -> None:
         bar = ttk.Frame(self)
         bar.pack(fill=tk.X, padx=4, pady=(0, 4))
@@ -465,9 +664,11 @@ class TestbenchGUI(tk.Tk):
             self._meter_addr.config(state=tk.DISABLED)
 
             self._status_label.config(text="Connected")
+            self._console(f"Connected: supply={supply_addr}, load={load_port}, meter={meter_addr}", "success")
             self._poll()
 
         except Exception as e:
+            self._console(f"Connection failed: {e}", "error")
             messagebox.showerror("Connection Error", str(e))
 
     def _disconnect(self) -> None:
@@ -490,12 +691,15 @@ class TestbenchGUI(tk.Tk):
         self._load_baud.config(state=tk.NORMAL)
         self._meter_addr.config(state=tk.NORMAL)
         self._status_label.config(text="Disconnected")
+        self._console("Disconnected")
 
     def _setup_all(self) -> None:
         self._send(Cmd.SETUP_ALL)
+        self._console("Setup All sent")
 
     def _safe_off(self) -> None:
         """Emergency stop -- bypasses command queue for minimum latency."""
+        self._console("SAFE OFF triggered", "error")
         if self.bench:
             try:
                 self.bench.safe_off()
@@ -512,19 +716,31 @@ class TestbenchGUI(tk.Tk):
             except Exception:
                 pass
         self._disconnect()
+        sys.stdout = self._orig_stdout
         self.destroy()
 
     # ── Polling / Data Update ─────────────────────────────────────────
 
     def _poll(self) -> None:
         """Called periodically to pull data from the worker and update UI."""
-        if not self.worker:
-            return
+        data = None
+
+        if self.worker:
+            data = self.worker.get_data()
+        else:
+            # During 2D sweep the worker is stopped; drain sweep queue
+            latest = None
+            while True:
+                try:
+                    latest = self._sweep_data_queue.get_nowait()
+                except queue.Empty:
+                    break
+            data = latest
 
-        data = self.worker.get_data()
         if data:
             error = data.get("_error")
             if error:
+                self._console(f"Error: {error}", "error")
                 self._status_label.config(text=f"Error: {error}")
             else:
                 self._update_readouts(data)
@@ -539,7 +755,9 @@ class TestbenchGUI(tk.Tk):
                     text=f"Connected | {self._point_count} pts | {hrs:02d}:{mins:02d}:{secs:02d}"
                 )
 
-        self.after(POLL_MS, self._poll)
+        # Keep polling as long as connected (bench exists)
+        if self.worker or self.bench:
+            self.after(POLL_MS, self._poll)
 
     def _update_readouts(self, data: dict) -> None:
         """Update all numeric labels from measurement data."""
@@ -554,12 +772,13 @@ class TestbenchGUI(tk.Tk):
         self._load_p_label.config(text=f"P: {_fmt(data['load_P'])} W")
 
         # Meter
-        self._m_u5.config(text=f"U5: {_fmt_eng(data['meter_U5'])} V")
-        self._m_i5.config(text=f"I5:  {_fmt_eng(data['meter_I5'])} A")
-        self._m_p5.config(text=f"P5: {_fmt_eng(data['meter_P5'])} W")
-        self._m_u6.config(text=f"U6: {_fmt_eng(data['meter_U6'])} V")
-        self._m_i6.config(text=f"I6:  {_fmt_eng(data['meter_I6'])} A")
-        self._m_p6.config(text=f"P6: {_fmt_eng(data['meter_P6'])} W")
+        fm = self._fmt_meter
+        self._m_u5.config(text=f"U5: {fm(data['meter_U5'])} V")
+        self._m_i5.config(text=f"I5:  {fm(data['meter_I5'])} A")
+        self._m_p5.config(text=f"P5: {fm(data['meter_P5'])} W")
+        self._m_u6.config(text=f"U6: {fm(data['meter_U6'])} V")
+        self._m_i6.config(text=f"I6:  {fm(data['meter_I6'])} A")
+        self._m_p6.config(text=f"P6: {fm(data['meter_P6'])} W")
 
         eff = data['meter_EFF1']
         if abs(eff) >= ERROR_THRESHOLD:
@@ -567,6 +786,23 @@ class TestbenchGUI(tk.Tk):
         else:
             self._m_eff.config(text=f"EFF1: {eff:.2f} %")
 
+        # ON/OFF indicators
+        supply_on = data.get("supply_on")
+        if supply_on is True:
+            self._sup_state_label.config(text="OUTPUT: ON", fg="#00aa00")
+        elif supply_on is False:
+            self._sup_state_label.config(text="OUTPUT: OFF", fg="#cc0000")
+        else:
+            self._sup_state_label.config(text="OUTPUT: ---", fg="#888888")
+
+        load_on = data.get("load_on")
+        if load_on is True:
+            self._load_state_label.config(text="LOAD: ON", fg="#00aa00")
+        elif load_on is False:
+            self._load_state_label.config(text="LOAD: OFF", fg="#cc0000")
+        else:
+            self._load_state_label.config(text="LOAD: ---", fg="#888888")
+
     def _update_graphs(self, data: dict) -> None:
         """Append data to series and redraw graphs."""
         now = time.time() - self._t0
@@ -592,12 +828,27 @@ class TestbenchGUI(tk.Tk):
 
         self._canvas.draw_idle()
 
+    # ── Format Helpers ─────────────────────────────────────────────────
+
+    def _on_meter_fmt_change(self, _event=None) -> None:
+        self._meter_fmt_sci = self._meter_fmt_combo.get() == "Scientific"
+
+    def _fmt_meter(self, val: float) -> str:
+        """Format a meter value based on the current format selection."""
+        if self._meter_fmt_sci:
+            return _fmt_eng(val)
+        return _fmt(val, decimals=4)
+
     # ── Command Helpers ───────────────────────────────────────────────
 
     def _send(self, cmd: Cmd, *args) -> None:
         """Send a command to the worker thread."""
         if self.worker:
             self.worker.send(cmd, *args)
+            if args:
+                self._console(f"{cmd.name} {' '.join(str(a) for a in args)}")
+            else:
+                self._console(cmd.name)
 
     def _send_float(self, cmd: Cmd, entry: ttk.Entry) -> None:
         """Parse an entry as float and send to worker."""
@@ -652,6 +903,329 @@ class TestbenchGUI(tk.Tk):
         except ValueError:
             pass
 
+    # ── Shade Profile ──────────────────────────────────────────────────
+
+    def _browse_profile(self) -> None:
+        path = filedialog.askopenfilename(
+            filetypes=[("CSV files", "*.csv"), ("All files", "*.*")],
+        )
+        if not path:
+            return
+        try:
+            self._profile_steps = MPPTTestbench.load_shade_profile(path)
+            n = len(self._profile_steps)
+            dur = self._profile_steps[-1]["time"] if self._profile_steps else 0
+            self._profile_path_label.config(text=path.split("/")[-1].split("\\")[-1])
+            self._profile_status.config(text=f"Loaded: {n} steps, {dur:.0f}s")
+        except Exception as e:
+            messagebox.showerror("Profile Error", str(e))
+
+    def _run_profile(self) -> None:
+        if not self._profile_steps:
+            messagebox.showwarning("No Profile", "Load a profile CSV first.")
+            return
+        if not self.worker:
+            return
+
+        try:
+            settle = float(self._profile_settle.get())
+        except ValueError:
+            settle = 2.0
+
+        n = len(self._profile_steps)
+        dur = self._profile_steps[-1]["time"] if self._profile_steps else 0
+        self._console(f"Shade profile started: {n} steps, {dur:.0f}s", "success")
+
+        self._profile_running = True
+        self._profile_index = 0
+        self._profile_t0 = time.time()
+        self._btn_profile_run.config(state=tk.DISABLED)
+        self._btn_profile_stop.config(state=tk.NORMAL)
+
+        # Turn outputs on with first step
+        first = self._profile_steps[0]
+        self._send(Cmd.SET_CURRENT, first["current_limit"])
+        self._send(Cmd.SET_VOLTAGE, first["voltage"])
+        self._send(Cmd.OUTPUT_ON)
+        if "load_mode" in first:
+            self._send(Cmd.SET_MODE, first["load_mode"])
+        if "load_value" in first:
+            self._send(Cmd.SET_MODE_VALUE, first.get("load_mode", "CC"), first["load_value"])
+        self._send(Cmd.LOAD_ON)
+
+        self._profile_schedule_next()
+
+    def _profile_schedule_next(self) -> None:
+        if not self._profile_running:
+            return
+        if self._profile_index >= len(self._profile_steps):
+            self._finish_profile()
+            return
+
+        step = self._profile_steps[self._profile_index]
+        target = self._profile_t0 + step["time"]
+        delay_ms = max(0, int((target - time.time()) * 1000))
+
+        self._profile_after_id = self.after(delay_ms, self._apply_profile_step)
+
+    def _apply_profile_step(self) -> None:
+        if not self._profile_running:
+            return
+
+        step = self._profile_steps[self._profile_index]
+        self._send(Cmd.SET_CURRENT, step["current_limit"])
+        self._send(Cmd.SET_VOLTAGE, step["voltage"])
+        if "load_mode" in step:
+            self._send(Cmd.SET_MODE, step["load_mode"])
+        if "load_value" in step:
+            self._send(Cmd.SET_MODE_VALUE, step.get("load_mode", "CC"), step["load_value"])
+
+        elapsed = time.time() - self._profile_t0
+        n = len(self._profile_steps)
+        self._profile_status.config(
+            text=f"Step {self._profile_index + 1}/{n}  "
+                 f"t={elapsed:.0f}s  V={step['voltage']:.1f}V  "
+                 f"I_lim={step['current_limit']:.1f}A"
+        )
+
+        self._profile_index += 1
+        self._profile_schedule_next()
+
+    def _stop_profile(self) -> None:
+        self._profile_running = False
+        if self._profile_after_id:
+            self.after_cancel(self._profile_after_id)
+            self._profile_after_id = None
+        self._btn_profile_run.config(state=tk.NORMAL)
+        self._btn_profile_stop.config(state=tk.DISABLED)
+        self._profile_status.config(text="Stopped")
+        self._console("Shade profile stopped", "warn")
+
+    def _finish_profile(self) -> None:
+        self._profile_running = False
+        self._btn_profile_run.config(state=tk.NORMAL)
+        self._btn_profile_stop.config(state=tk.DISABLED)
+        elapsed = time.time() - self._profile_t0
+        self._profile_status.config(text=f"Done ({elapsed:.0f}s)")
+        self._console(f"Shade profile complete ({elapsed:.0f}s)", "success")
+
+    # ── 2D Sweep (V × I) ───────────────────────────────────────────────
+
+    def _run_sweep_vi(self) -> None:
+        if not self.bench:
+            return
+        try:
+            params = {
+                "v_start": float(self._svi_v_start.get()),
+                "v_stop": float(self._svi_v_stop.get()),
+                "v_step": float(self._svi_v_step.get()),
+                "i_start": float(self._svi_i_start.get()),
+                "i_stop": float(self._svi_i_stop.get()),
+                "i_step": float(self._svi_i_step.get()),
+                "current_limit": float(self._svi_ilimit.get()),
+                "settle_time": float(self._svi_settle.get()),
+            }
+        except ValueError:
+            messagebox.showerror("Invalid Input", "Check sweep parameters.")
+            return
+
+        # Ask for output file
+        default_name = time.strftime("sweep_vi_%Y%m%d_%H%M%S.csv")
+        path = filedialog.asksaveasfilename(
+            defaultextension=".csv",
+            filetypes=[("CSV files", "*.csv")],
+            initialfile=default_name,
+        )
+        if not path:
+            return
+
+        self._console(
+            f"2D sweep: V={params['v_start']}-{params['v_stop']}V "
+            f"I={params['i_start']}-{params['i_stop']}A",
+            "success",
+        )
+
+        # Stop the normal worker so the sweep owns the instruments
+        if self.worker:
+            self.worker.stop()
+            self.worker = None
+
+        # Restart _poll so it drains the sweep data queue
+        self.after(POLL_MS, self._poll)
+
+        self._btn_svi_run.config(state=tk.DISABLED)
+        self._btn_svi_stop.config(state=tk.NORMAL)
+
+        stop_event = threading.Event()
+        self._svi_stop_event = stop_event
+
+        def _sweep_thread():
+            try:
+                self.after(0, lambda: self._svi_status.config(text="Running..."))
+                results = self._sweep_vi_loop(params, stop_event)
+                # Write CSV
+                if results:
+                    self._write_sweep_vi_csv(results, path)
+                    fname = path.split('/')[-1].split(chr(92))[-1]
+                    msg = f"Done: {len(results)} pts saved to {fname}"
+                    self._console(msg, "success")
+                else:
+                    msg = "Sweep stopped (no data)"
+                    self._console(msg, "warn")
+                self.after(0, lambda: self._svi_status.config(text=msg))
+            except Exception as e:
+                self._console(f"Sweep error: {e}", "error")
+                self.after(0, lambda: self._svi_status.config(text=f"Error: {e}"))
+            finally:
+                self.after(0, self._sweep_vi_done)
+
+        self._svi_thread = threading.Thread(target=_sweep_thread, daemon=True)
+        self._svi_thread.start()
+
+    def _sweep_vi_loop(self, p: dict, stop: threading.Event) -> list:
+        """Run the 2D sweep on a background thread. Returns list of SweepPoint."""
+        from testbench.bench import SweepPoint, IDLE_VOLTAGE
+
+        bench = self.bench
+        v_start, v_stop, v_step = p["v_start"], p["v_stop"], p["v_step"]
+        i_start, i_stop, i_step = p["i_start"], p["i_stop"], p["i_step"]
+        current_limit = p["current_limit"]
+        settle = p["settle_time"]
+
+        # Auto-correct directions
+        if v_start < v_stop and v_step < 0:
+            v_step = -v_step
+        elif v_start > v_stop and v_step > 0:
+            v_step = -v_step
+        if i_start < i_stop and i_step < 0:
+            i_step = -i_step
+        elif i_start > i_stop and i_step > 0:
+            i_step = -i_step
+
+        bench.supply.set_current(current_limit)
+        bench.supply.output_on()
+        bench.load.set_mode("CC")
+        bench.load.set_cc_current(i_start)
+        bench.load.load_on()
+
+        results = []
+        n = 0
+        v = v_start
+
+        try:
+            while not stop.is_set():
+                if v_step > 0 and v > v_stop + v_step / 2:
+                    break
+                if v_step < 0 and v < v_stop + v_step / 2:
+                    break
+
+                bench.supply.set_voltage(v)
+                i = i_start
+
+                while not stop.is_set():
+                    if i_step > 0 and i > i_stop + i_step / 2:
+                        break
+                    if i_step < 0 and i < i_stop + i_step / 2:
+                        break
+
+                    bench.load.set_cc_current(i)
+                    time.sleep(settle)
+                    if stop.is_set():
+                        break
+
+                    point = bench._record_point(v, current_limit, load_setpoint=i)
+                    results.append(point)
+                    n += 1
+
+                    # Push data for live graph/readout updates
+                    gui_data = {
+                        "supply_V": point.supply_voltage,
+                        "supply_I": point.supply_current,
+                        "supply_P": point.supply_power,
+                        "load_V": point.load_voltage,
+                        "load_I": point.load_current,
+                        "load_P": point.load_power,
+                        "meter_U5": point.supply_voltage,
+                        "meter_I5": point.supply_current,
+                        "meter_P5": point.input_power,
+                        "meter_U6": point.load_voltage,
+                        "meter_I6": point.load_current,
+                        "meter_P6": point.output_power,
+                        "meter_EFF1": point.efficiency,
+                        "supply_on": True,
+                        "load_on": True,
+                        "_error": None,
+                        "_timestamp": time.time(),
+                    }
+                    try:
+                        self._sweep_data_queue.put_nowait(gui_data)
+                    except queue.Full:
+                        try:
+                            self._sweep_data_queue.get_nowait()
+                        except queue.Empty:
+                            pass
+                        self._sweep_data_queue.put_nowait(gui_data)
+
+                    self.after(
+                        0,
+                        lambda v=v, i=i, pt=point, n=n: self._svi_status.config(
+                            text=f"[{n}] V={v:.1f}V I={i:.1f}A "
+                                 f"EFF={pt.efficiency:.1f}%"
+                        ),
+                    )
+
+                    i += i_step
+                v += v_step
+        finally:
+            bench.load.load_off()
+            bench.supply.set_voltage(IDLE_VOLTAGE)
+
+        return results
+
+    @staticmethod
+    def _write_sweep_vi_csv(results, path: str) -> None:
+        import csv as _csv
+
+        with open(path, "w", newline="") as f:
+            w = _csv.writer(f)
+            w.writerow([
+                "voltage_set", "current_limit", "load_setpoint",
+                "supply_V", "supply_I", "supply_P",
+                "load_V", "load_I", "load_P",
+                "input_power", "output_power", "efficiency",
+            ])
+            for pt in results:
+                w.writerow([
+                    f"{pt.voltage_set:.4f}", f"{pt.current_limit:.4f}",
+                    f"{pt.load_setpoint:.4f}",
+                    f"{pt.supply_voltage:.4f}", f"{pt.supply_current:.4f}",
+                    f"{pt.supply_power:.4f}",
+                    f"{pt.load_voltage:.4f}", f"{pt.load_current:.4f}",
+                    f"{pt.load_power:.4f}",
+                    f"{pt.input_power:.4f}", f"{pt.output_power:.4f}",
+                    f"{pt.efficiency:.4f}",
+                ])
+
+    def _stop_sweep_vi(self) -> None:
+        if self._svi_stop_event:
+            self._svi_stop_event.set()
+
+    def _sweep_vi_done(self) -> None:
+        self._btn_svi_run.config(state=tk.NORMAL)
+        self._btn_svi_stop.config(state=tk.DISABLED)
+        self._svi_thread = None
+        self._svi_stop_event = None
+        # Restart normal worker polling
+        if self.bench:
+            interval = 1.0
+            try:
+                interval = float(self._poll_interval.get())
+            except ValueError:
+                pass
+            self.worker = InstrumentWorker(self.bench, interval=interval)
+            self.worker.start()
+            self._poll()
+
     # ── Logging ───────────────────────────────────────────────────────
 
     _LOG_COLUMNS = [
@@ -679,9 +1253,11 @@ class TestbenchGUI(tk.Tk):
         self._btn_log_start.config(state=tk.DISABLED)
         self._btn_log_stop.config(state=tk.NORMAL)
         self._log_status.config(text=f"Logging to {path}")
+        self._console(f"CSV logging started: {path}")
 
     def _stop_log(self) -> None:
         if self._log_file:
+            self._console(f"CSV logging stopped ({self._log_count} samples)")
             self._log_file.close()
             self._log_file = None
             self._log_writer = None

testbench/gui_workers.py

@@ -99,6 +99,15 @@ class InstrumentWorker(threading.Thread):
                 data = self.bench.measure_all()
                 data["_error"] = None
                 data["_timestamp"] = time.time()
+                # Query output states for GUI indicators
+                try:
+                    data["supply_on"] = self.bench.supply.get_output_state()
+                except Exception:
+                    data["supply_on"] = None
+                try:
+                    data["load_on"] = self.bench.load.get_load_state()
+                except Exception:
+                    data["load_on"] = None
             except Exception as e:
                 data = {"_error": str(e), "_timestamp": time.time()}