[examples] Add Snippets for Accelerometers using OnboardIMU (#8087)

wpilibcExamples/example_projects.bzl

@@ -68,6 +68,9 @@ COMMANDS_V2_FOLDERS = [
 ]
 
 SNIPPETS_FOLDERS = [
+    "ADXLAccelerometers",
+    "AccelerometerCollision",
+    "AccelerometerFilter",
     "AnalogAccelerometer",
     "AnalogEncoder",
     "AnalogInput",
@@ -78,6 +81,7 @@ SNIPPETS_FOLDERS = [
     "EncoderDrive",
     "EncoderHoming",
     "LimitSwitch",
+    "OnboardIMU",
 ]
 
 TEMPLATES_FOLDERS = [

wpilibcExamples/src/main/cpp/snippets/ADXLAccelerometers/cpp/Robot.cpp

@@ -0,0 +1,38 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include <frc/ADXL345_I2C.h>
+#include <frc/AnalogInput.h>
+#include <frc/I2C.h>
+#include <frc/TimedRobot.h>
+
+/**
+ * ADXL346, 362 Accelerometer snippets for frc-docs.
+ * https://docs.wpilib.org/en/stable/docs/software/hardware-apis/sensors/accelerometers-software.html
+ */
+class Robot : public frc::TimedRobot {
+ public:
+  Robot() {}
+
+  void TeleopPeriodic() override {
+    // Gets the current acceleration in the X axis
+    m_accelerometer.GetX();
+    // Gets the current acceleration in the Y axis
+    m_accelerometer.GetY();
+    // Gets the current acceleration in the Z axis
+    m_accelerometer.GetZ();
+  }
+
+ private:
+  // Creates an ADXL345 accelerometer object on the MXP I2C port
+  // with a measurement range from -8 to 8 G's
+  frc::ADXL345_I2C m_accelerometer{frc::I2C::Port::kPort0,
+                                   frc::ADXL345_I2C::Range::kRange_8G};
+};
+
+#ifndef RUNNING_FRC_TESTS
+int main() {
+  return frc::StartRobot<Robot>();
+}
+#endif

wpilibcExamples/src/main/cpp/snippets/AccelerometerCollision/cpp/Robot.cpp

@@ -0,0 +1,40 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include <frc/OnboardIMU.h>
+#include <frc/TimedRobot.h>
+#include <frc/smartdashboard/SmartDashboard.h>
+#include <units/acceleration.h>
+
+/**
+ * Collision detection snippets for frc-docs.
+ * https://docs.wpilib.org/en/stable/docs/software/hardware-apis/sensors/accelerometers-software.html
+ */
+class Robot : public frc::TimedRobot {
+ public:
+  void RobotPeriodic() override {
+    // Gets the current accelerations in the X and Y directions
+    auto xAccel = m_accelerometer.GetAccelX();
+    auto yAccel = m_accelerometer.GetAccelY();
+    // Calculates the jerk in the X and Y directions
+    auto xJerk = (xAccel - m_prevXAccel) / GetPeriod();
+    auto yJerk = (yAccel - m_prevYAccel) / GetPeriod();
+    m_prevXAccel = xAccel;
+    m_prevYAccel = yAccel;
+
+    frc::SmartDashboard::PutNumber("X Jerk", xJerk.value());
+    frc::SmartDashboard::PutNumber("Y Jerk", yJerk.value());
+  }
+
+ private:
+  units::meters_per_second_squared_t m_prevXAccel = 0.0_mps_sq;
+  units::meters_per_second_squared_t m_prevYAccel = 0.0_mps_sq;
+  frc::OnboardIMU m_accelerometer{frc::OnboardIMU::MountOrientation::kFlat};
+};
+
+#ifndef RUNNING_FRC_TESTS
+int main() {
+  return frc::StartRobot<Robot>();
+}
+#endif

wpilibcExamples/src/main/cpp/snippets/AccelerometerFilter/cpp/Robot.cpp

@@ -0,0 +1,38 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include <frc/OnboardIMU.h>
+#include <frc/TimedRobot.h>
+#include <frc/filter/LinearFilter.h>
+#include <frc/smartdashboard/SmartDashboard.h>
+#include <units/acceleration.h>
+
+/**
+ * Accelerometer filtering snippets for frc-docs.
+ * https://docs.wpilib.org/en/stable/docs/software/hardware-apis/sensors/accelerometers-software.html
+ */
+class Robot : public frc::TimedRobot {
+ public:
+  void RobotPeriodic() override {
+    units::meters_per_second_squared_t XAccel = m_accelerometer.GetAccelX();
+    // Get the filtered X acceleration
+    units::meters_per_second_squared_t filteredXAccel =
+        m_xAccelFilter.Calculate(XAccel);
+
+    frc::SmartDashboard::PutNumber("X Acceleration", XAccel.value());
+    frc::SmartDashboard::PutNumber("Filtered X Acceleration",
+                                   filteredXAccel.value());
+  }
+
+ private:
+  frc::OnboardIMU m_accelerometer{frc::OnboardIMU::MountOrientation::kFlat};
+  frc::LinearFilter<units::meters_per_second_squared_t> m_xAccelFilter =
+      frc::LinearFilter<units::meters_per_second_squared_t>::MovingAverage(10);
+};
+
+#ifndef RUNNING_FRC_TESTS
+int main() {
+  return frc::StartRobot<Robot>();
+}
+#endif

wpilibcExamples/src/main/cpp/snippets/OnboardIMU/cpp/Robot.cpp

@@ -0,0 +1,45 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include <frc/OnboardIMU.h>
+#include <frc/TimedRobot.h>
+#include <frc/geometry/Rotation2d.h>
+#include <units/acceleration.h>
+#include <units/angle.h>
+
+/**
+ * Onboard IMU snippets for frc-docs.
+ * https://docs.wpilib.org/en/stable/docs/software/hardware-apis/sensors/accelerometers-software.html
+ */
+class Robot : public frc::TimedRobot {
+ public:
+  void TeleopPeriodic() override {
+    // Gets the current acceleration in the X axis
+    m_IMU.GetAccelX();
+    // Gets the current acceleration in the Y axis
+    m_IMU.GetAccelY();
+    // Gets the current acceleration in the Z axis
+    m_IMU.GetAccelZ();
+
+    // Gets the current angle in the X axis
+    m_IMU.GetAngleX();
+    // Gets the current angle in the Y axis
+    m_IMU.GetAngleY();
+    // Gets the current angle in the Z axis
+    m_IMU.GetAngleZ();
+
+    // Gets the current angle as a Rotation2D
+    m_IMU.GetRotation2d();
+  }
+
+ private:
+  // Creates an object for the Systemcore IMU
+  frc::OnboardIMU m_IMU{frc::OnboardIMU::MountOrientation::kFlat};
+};
+
+#ifndef RUNNING_FRC_TESTS
+int main() {
+  return frc::StartRobot<Robot>();
+}
+#endif

wpilibcExamples/src/main/cpp/snippets/snippets.json

@@ -103,5 +103,48 @@
     ],
     "foldername": "AnalogAccelerometer",
     "gradlebase": "cpp"
+  },
+  {
+    "name": "ADXLAccelerometers",
+    "description": "Snippets of ADXL 345 and 362 Accelerometers for frc-docs.",
+    "tags": [
+      "Hardware",
+      "Accelerometer"
+    ],
+    "foldername": "ADXLAccelerometers",
+    "gradlebase": "cpp"
+  },
+  {
+    "name": "AccelerometerCollisionDetection",
+    "description": "Snippets of Accelerometer collision detection for frc-docs.",
+    "tags": [
+      "Hardware",
+      "Accelerometer",
+      "IMU"
+    ],
+    "foldername": "AccelerometerCollision",
+    "gradlebase": "cpp"
+  },
+  {
+    "name": "AccelerometerFilter",
+    "description": "Snippets of filtering Accelerometer for frc-docs.",
+    "tags": [
+      "Hardware",
+      "Accelerometer",
+      "IMU"
+    ],
+    "foldername": "AccelerometerFilter",
+    "gradlebase": "cpp"
+  },
+  {
+    "name": "OnboardIMU",
+    "description": "Snippets of OnboardIMU for frc-docs.",
+    "tags": [
+      "Hardware",
+      "Accelerometer",
+      "IMU"
+    ],
+    "foldername": "OnboardIMU",
+    "gradlebase": "cpp"
   }
 ]