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Quick Start Examples 💡

This section provides a quick guide on how to run a basic real-time loop using the Delta6 Python SDK.

The example script is located at:

delta6_python_SDK/example.py

1. Purpose of This Example​

The example.py script demonstrates:

  • Calibrating the sensors
  • Reading encoder data in real-time
  • Computing forward kinematics
  • Visualizing the estimated end-effector forces

It serves as a minimal starting point to verify that all hardware and software are working correctly.

2. How to Run​

Activate the Python environment first:

# On Ubuntu
source venv/bin/activate

# On Windows
source venv/Scripts/activate

Then run the example:

python delta6_python_SDK/example.py --port /dev/ttyACM0 --freq 50
  • Replace /dev/ttyACM0 with your Arduino Nano Every's actual port.
  • --freq controls the loop frequency (default is 50 Hz).

3. How It Works​

The script defines a MainLoop class (derived from RTLoop) to organize initialization, looping, and shutdown behaviors.

The full execution flow is as follows:

Initialization (setup() method)​

1️⃣ Sensor Calibration

  • Code: sensor_calibration(nano_port=self.nano_port)
  • Prompts the user to move the device to a neutral position and records zero offsets.

2️⃣ Start Encoder Reading Loop

  • Code: self.read_encoder_loop = ReadEncoderLoop(nano_port=self.nano_port, encoder_dir=ENCODER_DIR)
  • Encoder angles are read asynchronously at high frequency.

3️⃣ Initialize Delta6 Kinematics Model

  • Code: self.Delta6 = DeltaRobot()
  • Creates a new DeltaRobot instance to calculate forward kinematics from encoder readings.

4️⃣ Start Force Visualizer

  • Code: 
    self.force_visualizer = ForceVisualizer(...)
    self.force_visualizer.start()
  • A real-time window opens to display the estimated end-effector forces.

5️⃣ Start Real-Time Loop Spin

  • Code: super().setup()
  • Prepares the internal threading/timing logic to start looping.

Main Loop (loop() method)​

Each real-time cycle (50 Hz by default):

  • Read encoder data
    Code: encoder_reading = self.read_encoder_loop.get_encoder_reading()

  • Update Delta6 model
    Code: self.Delta6.update(*encoder_reading)

  • Compute and print end-effector pose
    Code:

    delta6_pose_reading = self.Delta6.get_FK_result()
    print(f"End-effector pose (x, y, z, roll, pitch, yaw): {delta6_pose_reading}")

  • Update the force visualizer
    Code:

    delta6_end_force = self.Delta6.get_end_force()
    self.force_visualizer.update_forces([delta6_end_force])

Example console output:

End-effector pose (x, y, z, roll, pitch, yaw): [0.012, 0.005, 0.230, 0.01, -0.02, 0.00]

Shutdown (shutdown() method)​

When exiting the program (e.g., Ctrl+C):

  • Stop the force visualizer
    Code: self.force_visualizer.stop()

  • Terminate real-time loop cleanly
    Code: super().shutdown()

  • Print shutdown confirmation
    Code: print("Force visualizer shutdown.")

4. Notes​

📌 Tip:
You can adjust the --freq parameter to higher values (e.g., 100 Hz) for faster updates, depending on your PC performance.

⚡ Warning:
Always run sensor calibration before starting meaningful data collection, to avoid force/pose estimation errors.

🎯 Congratulations!
By running this quick start example, you have verified that your Delta6 system hardware and software are properly set up!