feat: make library compatible with Nano 33 BLE Sense rev2

* Needs arduino-libraries/Arduino_BMI270_BMM150#56 to properly handle BMI270 in FIFO mode
* The user should define NANO33_BLE_REV2 as early as possible to include the proper libraries (fixed the examples)
* `while (IMU.accelerationAvailable())` replaced with `if (IMU.accelerationAvailable())`, shouldn't change anything in existing code since Arduino_LSM9DS1 was always returing only one sample

Author: facchinm

examples/magic_wand/imu_provider.h

@@ -2,6 +2,10 @@
 #define MAGIC_WAND_IMU_PROVIDER_H
 
 #include <Arduino_LSM9DS1.h>
+#ifdef NANO33_BLE_REV2
+#include <Arduino_BMI270_BMM150.h>
+#endif
+
 #include <ArduinoBLE.h>
 
 namespace {
@@ -60,15 +64,15 @@ namespace {
     *new_accelerometer_samples = 0;
     *new_gyroscope_samples = 0;
     // Loop through new samples and add to buffer
-    while (IMU.accelerationAvailable()) {
+    if (IMU.accelerationAvailable()) {
       const int gyroscope_index = (gyroscope_data_index % gyroscope_data_length);
       gyroscope_data_index += 3;
       float* current_gyroscope_data = &gyroscope_data[gyroscope_index];
       // Read each sample, removing it from the device's FIFO buffer
       if (!IMU.readGyroscope(
           current_gyroscope_data[0], current_gyroscope_data[1], current_gyroscope_data[2])) {
         Serial.println("Failed to read gyroscope data");
-        break;
+        //break;
       }
       *new_gyroscope_samples += 1;
 
@@ -79,7 +83,7 @@ namespace {
       if (!IMU.readAcceleration(
           current_acceleration_data[0], current_acceleration_data[1], current_acceleration_data[2])) {
         Serial.println("Failed to read acceleration data");
-        break;
+        //break;
       }
       *new_accelerometer_samples += 1;
     }

examples/magic_wand/magic_wand.ino

@@ -12,6 +12,9 @@ limitations under the License.
 
 #include <TensorFlowLite.h>
 
+// if using Nano BLE rev2, uncomment next line
+// #define NANO33_BLE_REV2
+
 #include "tensorflow/lite/micro/micro_error_reporter.h"
 #include "tensorflow/lite/micro/micro_interpreter.h"
 #include "tensorflow/lite/micro/micro_mutable_op_resolver.h"

examples/test_IMU/test_IMU.ino

@@ -7,6 +7,8 @@
 */
 
 #include <Arduino_LSM9DS1.h>
+// if using Nano BLE rev2, uncomment next line
+// #include <Arduino_BMI270_BMM150.h>
 
 int imuIndex = 0; // 0 - accelerometer, 1 - gyroscope, 2 - magnetometer
 bool commandRecv = false; // flag used for indicating receipt of commands from serial port
@@ -22,6 +24,8 @@ void setup() {
     while (1);
   }
 
+  IMU.setContinuousMode();
+
   Serial.println("Welcome to the IMU test for the built-in IMU on the Nano 33 BLE Sense\n");
   Serial.println("Available commands:");
   Serial.println("a - display accelerometer readings in g's in x, y, and z directions");