fixed normal force negative display scale problem

src/sensor_bench/exhibition_app.py

@@ -47,8 +47,10 @@ from .acquisition import (
 from .camera_discovery import list_cameras, pick_default_camera
 from .dd06_acquisition import Dd06AcquisitionWorker
 from .force_calibration import (
-    CALIBRATED_FORCE_Y_MAX,
-    CALIBRATED_FORCE_Y_MIN,
+    CALIBRATED_NORMAL_FORCE_Y_MAX,
+    CALIBRATED_NORMAL_FORCE_Y_MIN,
+    CALIBRATED_SHEAR_FORCE_Y_MAX,
+    CALIBRATED_SHEAR_FORCE_Y_MIN,
     FORCE_SAMPLE_RATE_HZ,
     PLOT_BUFFER_POINTS,
     PLOT_WINDOW_SEC,
@@ -896,20 +898,44 @@ class ExhibitionWindow(QMainWindow):
         )
         self.image_label.setPixmap(scaled)
 
+    def _calibrated_y_range(self, channel_index: int) -> tuple[float, float]:
+        if channel_index == 0:
+            return CALIBRATED_NORMAL_FORCE_Y_MIN, CALIBRATED_NORMAL_FORCE_Y_MAX
+        return CALIBRATED_SHEAR_FORCE_Y_MIN, CALIBRATED_SHEAR_FORCE_Y_MAX
+
+    def _apply_calibrated_y_axis(self, plot, channel_index: int) -> None:
+        axis = plot.getAxis("left")
+        if channel_index == 0:
+            ticks = [(0, "0"), (5, "5"), (10, "10"), (15, "15"), (20, "20")]
+        else:
+            ticks = [
+                (-20, "-20"),
+                (-10, "-10"),
+                (0, "0"),
+                (10, "10"),
+                (20, "20"),
+            ]
+        axis.setTicks([ticks])
+
     def _update_plots(self) -> None:
         state = self.force_history.state()
         if state is None:
             return
         for i, curve in enumerate(self.curves):
             x = state.times
-            y = state.values[:, i]
+            y = state.values[:, i].copy()
+            if self._force_calibrated and i == 0:
+                y = np.maximum(y, 0.0)
             curve.setData(x, y)
             if self._force_calibrated:
-                ymin, ymax = CALIBRATED_FORCE_Y_MIN, CALIBRATED_FORCE_Y_MAX
+                ymin, ymax = self._calibrated_y_range(i)
+                self._apply_calibrated_y_axis(self.plots[i], i)
             else:
                 ymin, ymax = state.y_ranges[i]
+                self.plots[i].getAxis("left").setTicks(None)
             self.plots[i].setYRange(ymin, ymax, padding=0)
-            self.dot_cores[i].setData(x[-1:], y[-1:])
+            dot_y = y[-1:]
+            self.dot_cores[i].setData(x[-1:], dot_y)
         x0, x1 = state.x_range
         for plot in self.plots:
             plot.setXRange(x0, x1, padding=0)

src/sensor_bench/force_calibration.py

@@ -11,8 +11,10 @@ FORCE_SAMPLE_RATE_HZ = 30.0
 PLOT_BUFFER_POINTS = 120
 PLOT_WINDOW_SEC = PLOT_BUFFER_POINTS / FORCE_SAMPLE_RATE_HZ
 Y_AXIS_MIN_SPAN = 20000.0
-CALIBRATED_FORCE_Y_MIN = -20.0
-CALIBRATED_FORCE_Y_MAX = 20.0
+CALIBRATED_NORMAL_FORCE_Y_MIN = 0.0
+CALIBRATED_NORMAL_FORCE_Y_MAX = 20.0
+CALIBRATED_SHEAR_FORCE_Y_MIN = -20.0
+CALIBRATED_SHEAR_FORCE_Y_MAX = 20.0
 Y_RANGE_ALPHA = 0.5
 LOWPASS_CUTOFF_HZ = 10.0