nrf/boards/arduino_nano_33_ble_sense: Add support for REV-2 chipset.

These changes allow the firmware to support both the REV-1 and REV-2
versions of the board:
- Freeze the new device drivers used in REV-2.
- Add a board-level module that abstracts the IMU chipset.

ports/nrf/boards/arduino_nano_33_ble_sense/manifest.py

@@ -2,3 +2,7 @@ include("$(PORT_DIR)/modules/manifest.py")
 require("hts221")
 require("lps22h")
 require("lsm9ds1")
+require("bmm150")
+require("bmi270")
+require("hs3003")
+freeze("./modules")

ports/nrf/boards/arduino_nano_33_ble_sense/modules/imu.py

@@ -0,0 +1,45 @@
+"""
+IMU module for Arduino Nano BLE 33 SENSE (REV1 and REV2).
+
+Example usage:
+
+import time
+import imu
+from machine import Pin, I2C
+
+bus = I2C(1, scl=Pin(15), sda=Pin(14))
+imu = imu.IMU(bus)
+
+while (True):
+    print('Accelerometer: x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}'.format(*imu.accel()))
+    print('Gyroscope:     x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}'.format(*imu.gyro()))
+    print('Magnetometer:  x:{:>8.3f} y:{:>8.3f} z:{:>8.3f}'.format(*imu.magnet()))
+    print("")
+    time.sleep_ms(100)
+"""
+
+import time
+
+
+class IMU:
+    def __init__(self, bus):
+        """Initalizes Gyro, Accelerometer and Magnetometer using default values."""
+        if 0x68 in bus.scan():
+            from bmm150 import BMM150
+            from bmi270 import BMI270
+
+            magnet = BMM150(bus)
+            self.imu = BMI270(bus, bmm_magnet=magnet)
+        else:
+            from lsm9ds1 import LSM9DS1
+
+            self.imu = LSM9DS1(bus)
+
+    def gyro(self):
+        return self.imu.gyro()
+
+    def accel(self):
+        return self.imu.accel()
+
+    def magnet(self):
+        return self.imu.magnet()