Initial implementation of interrupt-based wrist tilt detection on BMA425

wasp/boards/pinetime/manifest.py

@@ -22,6 +22,7 @@ freeze('../..', manifest_240x240.manifest +
         'gadgetbridge.py',
         'ppg.py',
         'shell.py',
+        'motion.py',
         'wasp.py',
     ),
     opt=3

wasp/boards/pinetime/watch.py.in

@@ -90,7 +90,7 @@ try:
             Signal(Pin('CHARGING', Pin.IN), invert=True),
             Signal(Pin('USB_PWR', Pin.IN), invert=True))
     i2c = I2C(1, scl='I2C_SCL', sda='I2C_SDA')
-    accel = BMA421(i2c)
+    accel = BMA421(i2c, Pin('ACCEL_INT', Pin.IN))
     hrs = HRS3300(i2c)
     touch = CST816S(i2c,
                     Pin('TP_INT', Pin.IN), Pin('TP_RST', Pin.OUT, value=0),

wasp/drivers/bma421.py

@@ -7,6 +7,8 @@
 
 import bma42x
 import time
+import motion
+from machine import Pin
 
 # Sensor orientation definition.
 # The 6 most significant bits define the indexes of the x, y, and z values
@@ -28,13 +30,18 @@ class BMA421:
 
     .. automethod:: __init__
     """
-    def __init__(self, i2c, orientation=_DEFAULT_ORIENTATION):
+    def __init__(self, i2c, intr=None, orientation=_DEFAULT_ORIENTATION):
         """Configure the driver.
 
         :param machine.I2C i2c: I2C bus used to access the sensor.
         """
         self._dev = bma42x.BMA42X(i2c)
         self._orientation = orientation
+        self._gesture_int = intr
+        self._gesture_event = motion.AccelGestureEvent.NONE
+
+        if self._gesture_int != None:
+            self._gesture_int.irq(trigger=Pin.IRQ_FALLING, handler=self.handle_interrupt)
 
     def reset(self):
         """Reset and reinitialize the sensor."""
@@ -60,6 +67,29 @@ class BMA421:
         # Software readout is remapped manually in accel_xyz().
         dev.set_remap_axes(self._orientation)
 
+        # Enable gesture interrupts
+        dev.set_int_pin_config(int_line=bma42x.INTR1_MAP,
+                                 edge_ctrl=bma42x.LEVEL_TRIGGER,
+                                 lvl=bma42x.ACTIVE_LOW,
+                                 od=bma42x.PUSH_PULL,
+                                 output_en=True, input_en=False)
+        dev.feature_enable(bma42x.WRIST_WEAR, True)
+        #dev.feature_enable(bma42x.DOUBLE_TAP, True)
+        dev.map_interrupt(bma42x.INTR1_MAP, bma42x.WRIST_WEAR_INT, True)
+
+    def handle_interrupt(self, pin_obj):
+        """Interrupt handler for gesture events originating from the sensor"""
+        self._dev.read_int_status() # TODO: Actually read status from the register
+        self._gesture_event = motion.AccelGestureEvent.WRIST_TILT
+
+    def get_gesture_event(self):
+        """Receive the latest gesture event if any"""
+        return self._gesture_event
+
+    def reset_gesture_event(self):
+        """Call after processing the gesture event"""
+        self._gesture_event = motion.AccelGestureEvent.NONE
+
     @property
     def steps(self):
         """Report the number of steps counted."""

wasp/modules/bma42x-upy

@@ -1 +1 @@
-Subproject commit 85622fc37610ebb3821f0b315c37c69a4bffa72d
+Subproject commit 905652f9fd6541283591cf6e085c31f9aa63bf40

wasp/motion.py

@@ -0,0 +1,7 @@
+from micropython import const
+
+class AccelGestureEvent():
+    """Enumerated ids for accelerometer-based gesture events
+    """
+    NONE = const(0)
+    WRIST_TILT = const(1)

wasp/wasp.py

@@ -20,6 +20,7 @@ import micropython
 import sys
 import watch
 import widgets
+import motion
 
 from apps.launcher import LauncherApp
 from apps.pager import PagerApp, CrashApp, NotificationApp
@@ -498,11 +499,14 @@ class Manager():
                 self.wake()
 
         if self.raise_wake:
-            now = rtc.get_uptime_ms()
+            if watch.accel.get_gesture_event() == motion.AccelGestureEvent.WRIST_TILT:
-            if now >= self.accel_poll_expiry:
+                watch.accel.reset_gesture_event()
-                self.accel_poll_expiry = (now + self.accel_poll_ms)
+                self.wake()
-                if self._do_raise_wake():
+            #now = rtc.get_uptime_ms()
-                    self.wake()
+            #if now >= self.accel_poll_expiry:
+            #    self.accel_poll_expiry = (now + self.accel_poll_ms)
+            #    if self._do_raise_wake():
+            #        self.wake()
     
     def _do_raise_wake(self):