lis2mdl: Auto-trigger single conversion in idle mode.

lib/lis2mdl/lis2mdl/device.py

@@ -168,6 +168,16 @@ def set_hw_offsets(self, x: int, y: int, z: int):
     # --- READ functions ---
     ##
 
+    def _ensure_data(self):
+        """Trigger a single conversion if the sensor is in idle mode."""
+        if self.is_idle():
+            self.set_mode("single")
+            for _ in range(50):
+                if self.data_ready():
+                    return
+                sleep_ms(2)
+            raise OSError("LIS2MDL data ready timeout")
+
     def read_magnet_raw(self):
         """Reads the raw magnetic field (LSB). Same as read_magnet(), but more explicit."""
         return self.read_magnet()  # (x,y,z) int16 LSB
@@ -222,6 +232,7 @@ def _to_int16(v):
 
     def read_magnet(self):
         # Read the raw magnetic field data (X, Y, Z) from the sensor.
+        self._ensure_data()
         buf = self.i2c.readfrom_mem(self.address, LIS2MDL_OUTX_L_REG | 0x80, 6)
         x = self._to_int16((buf[1] << 8) | buf[0])
         y = self._to_int16((buf[3] << 8) | buf[2])
@@ -232,6 +243,7 @@ def read_magnet(self):
 
     def read_temperature_raw(self) -> int:
         """Reads the raw temperature (LSB), 8 LSB/°C, absolute offset not guaranteed."""
+        self._ensure_data()
         lo = self._read_reg(LIS2MDL_TEMP_OUT_L_REG)
         hi = self._read_reg(LIS2MDL_TEMP_OUT_H_REG)
         v = (hi << 8) | lo

tests/scenarios/lis2mdl.yaml

@@ -86,6 +86,69 @@ tests:
     expect_range: [19.0, 21.0]
     mode: [mock]
 
+  # ----- Auto-trigger -----
+
+  - name: "Magnetic field readable after power down"
+    action: script
+    script: |
+      dev.power_down()
+      x, y, z = dev.read_magnet()
+      result = isinstance(x, int) and isinstance(y, int) and isinstance(z, int)
+    expect_true: true
+    mode: [mock]
+
+  - name: "Temperature readable after power down"
+    action: script
+    script: |
+      dev.power_down()
+      t = dev.read_temperature_c()
+      result = isinstance(t, float)
+    expect_true: true
+    mode: [mock]
+
+  - name: "Auto-trigger writes single mode to CFG_REG_A"
+    action: script
+    script: |
+      dev.power_down()
+      i2c.clear_write_log()
+      dev.read_magnet()
+      log = i2c.get_write_log()
+      wrote_cfg_a = any(reg == 0x60 for reg, data in log)
+      result = wrote_cfg_a
+    expect_true: true
+    mode: [mock]
+
+  - name: "No auto-trigger when already active"
+    action: script
+    script: |
+      dev.read_magnet()
+      i2c.clear_write_log()
+      dev.read_magnet()
+      log = i2c.get_write_log()
+      result = len(log) == 0
+    expect_true: true
+    mode: [mock]
+
+  - name: "Fresh magnitude after power down"
+    action: script
+    script: |
+      dev.power_down()
+      mag = dev.magnitude_uT()
+      result = 10.0 < mag < 300.0
+    expect_true: true
+    mode: [hardware]
+
+  - name: "Fresh temperature after power down"
+    action: script
+    script: |
+      dev.power_down()
+      t = dev.read_temperature_c()
+      result = 10.0 < t < 45.0
+    expect_true: true
+    mode: [hardware]
+
+  # ----- Hardware -----
+
   - name: "Magnitude in plausible range"
     action: call
     method: magnitude_uT