robot_arm

Arduino-based 4-DOF hobby robot arm (base yaw + 3 planar joints) with servo control, forward/inverse kinematics, and smooth joint-space trajectories.

Highlights

• Forward kinematics (FK::forward)
• Inverse kinematics (IK::inverse)
• Smooth joint-space interpolation (JointTrajectory)
• Servo zero-position calibration sketch (src/callibration/callibration.ino)

Media

CAD

Real-life assembly

Repo layout

• src/main/main.ino: main sketch (servo control + IK/FK prints + trajectory execution)
• src/main/ik.*: inverse kinematics
• src/main/fk.*: forward kinematics
• src/main/traj.*: smoothstep-interpolated joint trajectory
• src/main/Pose.hpp, src/main/JointVals.hpp: small data types
• src/callibration/callibration.ino: servo calibration

Quick start

1. Open src/main/main.ino in Arduino IDE (or PlatformIO).
2. Connect servos to D8–D11 (base, joint 1–3).
3. Power servos with an external 5–6V supply and ensure common ground.
4. Upload and open Serial Monitor at 9600 baud.

Acknowledgments

Trajectory generation and forward/inverse kinematics based on concepts from Modern Robotics: Mechanics, Planning, and Control by Kevin M. Lynch and Frank C. Park.