Improvements on datarate, added dataReady function, fixed accelerometer and gyroscope divisor

adafruit_icm20x.py

@@ -60,6 +60,15 @@
 _ICM20X_REG_INT_ENABLE_0 = 0x10  # Interrupt enable register 0
 _ICM20X_REG_INT_ENABLE_1 = 0x11  # Interrupt enable register 1
 
+_ICM20X_REG_INT_STATUS_0 = (
+    0x19  # Interrupt status register 0   Wake on motion, DMP int, i2c int
+)
+_ICM20X_REG_INT_STATUS_1 = (
+    0x1A  # Interrupt status register 1   data register from all sensors
+)
+_ICM20X_REG_INT_STATUS_2 = 0x1B  # Interrupt status register 2   FIFO overflow
+_ICM20X_REG_INT_STATUS_3 = 0x1C  # Interrupt status register 3   Watermark interrupt
+
 # Bank 2
 _ICM20X_GYRO_SMPLRT_DIV = 0x00
 _ICM20X_GYRO_CONFIG_1 = 0x01
@@ -159,6 +168,8 @@ class ICM20X:  # pylint:disable=too-many-instance-attributes
 
     _lp_config_reg = UnaryStruct(_ICM20X_LP_CONFIG, ">B")
 
+    _data_ready = ROBit(_ICM20X_REG_INT_STATUS_1, 0)
+
     _i2c_master_cycle_en = RWBit(_ICM20X_LP_CONFIG, 6)
     _accel_cycle_en = RWBit(_ICM20X_LP_CONFIG, 5)
     _gyro_cycle_en = RWBit(_ICM20X_LP_CONFIG, 4)
@@ -237,6 +248,8 @@ def initialize(self):
         self.accelerometer_data_rate_divisor = 20  # ~53.57Hz
         self.gyro_data_rate_divisor = 10  # ~100Hz
 
+        self._gravity = G_TO_ACCEL
+
     def reset(self):
         """Resets the internal registers and restores the default settings"""
         self._bank = 0
@@ -247,6 +260,11 @@ def reset(self):
         while self._reset:
             sleep(0.005)
 
+    def data_ready(self):
+        """Checks if new data is available"""
+        self._bank = 0
+        return self._data_ready
+
     @property
     def _sleep(self):
         self._bank = 0
@@ -286,7 +304,9 @@ def gyro(self):
         return (x, y, z)
 
     def _scale_xl_data(self, raw_measurement):
-        return raw_measurement / AccelRange.lsb[self._cached_accel_range] * G_TO_ACCEL
+        return (
+            raw_measurement / AccelRange.lsb[self._cached_accel_range] * self._gravity
+        )
 
     def _scale_gyro_data(self, raw_measurement):
         return (
@@ -422,7 +442,8 @@ def accelerometer_data_rate(self, value):
             raise AttributeError(
                 "Accelerometer data rate must be between 0.27 and 1125.0"
             )
-        self.accelerometer_data_rate_divisor = value
+        divisor = round(((1125.0 - value) / value))
+        self.accelerometer_data_rate_divisor = divisor
 
     @property
     def gyro_data_rate(self):
@@ -445,8 +466,7 @@ def gyro_data_rate(self):
     def gyro_data_rate(self, value):
         if value < self._gyro_rate_calc(4095) or value > self._gyro_rate_calc(0):
             raise AttributeError("Gyro data rate must be between 4.30 and 1100.0")
-
-        divisor = round(((1125.0 - value) / value))
+        divisor = round(((1100.0 - value) / value))
         self.gyro_data_rate_divisor = divisor
 
     @property
@@ -511,6 +531,15 @@ def _low_power(self, enabled):
         self._bank = 0
         self._low_power_en = enabled
 
+    @property
+    def gravity(self):
+        """The gravity magnitude in m/s^2."""
+        return self._gravity
+
+    @gravity.setter
+    def gravity(self, value):
+        self._gravity = value
+
 
 class ICM20649(ICM20X):
     """Library for the ST ICM-20649 Wide-Range 6-DoF Accelerometer and Gyro.
@@ -740,7 +769,7 @@ def _mag_id(self):
 
     @property
     def magnetic(self):
-        """The current magnetic field strengths onthe X, Y, and Z axes in uT (micro-teslas)"""
+        """The current magnetic field strengths on the X, Y, and Z axes in uT (micro-teslas)"""
 
         self._bank = 0
         full_data = self._raw_mag_data

docs/examples.rst

@@ -16,6 +16,15 @@ Test using all the ICM20649 sensor capabilities
     :caption: examples/examples/icm20x_icm20649_full_test.py
     :linenos:
 
+ICM20649 data rate test
+-----------------------
+
+Test using all the ICM20649 sensor capabilities
+
+.. literalinclude:: ../examples/icm20x_icm20649_data_rate_test.py
+    :caption: examples/examples/icm20x_icm20649_data_rate_test.py
+    :linenos:
+
 ICM20948 Simple test
 --------------------
 

examples/icm20x_icm20649_data_rate_test.py

@@ -0,0 +1,36 @@
+# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
+# SPDX-License-Identifier: MIT
+
+import time
+import board
+from adafruit_icm20x import ICM20649, AccelRange, GyroRange
+
+i2c = board.I2C()  # uses board.SCL and board.SDA
+
+ism = ICM20649(i2c, address=0x69)
+
+ism.accelerometer_range = AccelRange.RANGE_4G
+print("Accelerometer range set to: %d g" % AccelRange.string[ism.accelerometer_range])
+
+ism.gyro_range = GyroRange.RANGE_500_DPS
+print("Gyro range set to: %d DPS" % GyroRange.string[ism.gyro_range])
+
+ism.gyro_data_rate = 1100  # 1100 max
+ism.accelerometer_data_rate = 1125  # 1125 max
+
+print("Gyro rate: {:f}".format(ism.gyro_data_rate))
+print("Accel rate: {:f}".format(ism.accelerometer_data_rate))
+
+ism.gravity = 9.8
+
+previousTime = time.perf_counter()
+while True:
+    if ism.data_ready:
+        currentTime = time.perf_counter()
+        print("\033[2J")
+        print(
+            "Accel X:%5.2f Y:%5.2f Z:%5.2f ms^2 "
+            "Gyro X:%8.3f Y:%8.3f Z:%8.3f degrees/s Sample Rate: %8.1f Hz"
+            % (*ism.acceleration, *ism.gyro, (1 / (currentTime - previousTime)))
+        )
+        previousTime = currentTime

examples/icm20x_icm20649_full_test.py

@@ -17,7 +17,7 @@ def printNewMax(value, current_max, axis):
 i2c = board.I2C()  # uses board.SCL and board.SDA
 # i2c = board.STEMMA_I2C()  # For using the built-in STEMMA QT connector on a microcontroller
 
-ism = ICM20649(i2c)
+ism = ICM20649(i2c, address=0x69)
 
 ism.accelerometer_range = AccelRange.RANGE_30G
 print("Accelerometer range set to: %d g" % AccelRange.string[ism.accelerometer_range])
@@ -28,8 +28,8 @@ def printNewMax(value, current_max, axis):
 ax_max = ay_max = az_max = 0
 gx_max = gy_max = gz_max = 0
 
-ism.gyro_data_rate = 125
-ism.accelerometer_data_rate = 4095
+ism.gyro_data_rate = 1100
+ism.accelerometer_data_rate = 1125
 st = time.monotonic()
 while time.monotonic() - st < 0.250:
     print(

examples/icm20x_icm20649_simpletest.py

@@ -7,7 +7,7 @@
 
 i2c = board.I2C()  # uses board.SCL and board.SDA
 # i2c = board.STEMMA_I2C()  # For using the built-in STEMMA QT connector on a microcontroller
-icm = adafruit_icm20x.ICM20649(i2c)
+icm = adafruit_icm20x.ICM20649(i2c, address=0x69)
 
 while True:
     print("Acceleration: X:%.2f, Y: %.2f, Z: %.2f m/s^2" % (icm.acceleration))