Troubleshooting Guide

        Diagnosis and Solutions for Common Issues

1. Hardware Issues

Q: Motors not moving after power-on?

                **Possible Causes:**

• Power not connected or voltage insufficient

• A4988 driver not properly inserted

• Motor enable pin (ENABLE) wired incorrectly

              **Solutions:**
  

• Use multimeter to check 12V power supply voltage

• Check if A4988 indicator LED is on

• Send M17 to manually enable motors

• Check if GPIO12 (ENABLE) is wired correctly

Q: A4988 overheating?

                **Causes:** Current limit set too high

                **Solution:**

• Power off immediately

• Install heat sink

• Adjust A4988 potentiometer (counterclockwise to reduce current)

• Reference current formula: Vref = I × 8 × Rs (Rs=0.1Ω)

• For NEMA17 (1.5A): Vref ≈ 1.2V

Q: Vacuum pump not working?

                **Check Items:**

• Relay wiring correct (input, VCC, GND)

• Relay indicator LED lights up when sending M121

• Pump power connection correct (12V)

• Test pump directly connected to power supply

Q: Poor suction effect?

                **Possible Causes:**

• Air leak in pneumatic tubing connections

• Solenoid valve damaged

• Suction cup worn out

              **Solutions:**
  

• Check all tubing connections, ensure tight fit

• Manually test valve (should click when energized)

• Replace aged suction cup

Q: Abnormal mechanical noise?

                **Check:**

• Ball joints properly installed, not too tight/loose

• Gear meshing correct, no missing teeth

• Motor mounting screws tight

• No interference with other components during arm movement

2. Software Issues

Q: Serial port connection failed?

                **Solution:**

• Check port number: Open Device Manager → Ports (COM & LPT) to confirm correct COM port

• Install driver: Download CP2102 or CH340 driver

• Close other programs: Ensure Arduino IDE or other serial tools are not occupying the port

• Replug USB: Try different USB port

Q: Python dependency error?

# Upgrade pip
python -m pip install --upgrade pip

# Clear cache and reinstall
pip cache purge
pip install -r requirements.txt --force-reinstall

# If specific library fails (e.g., opencv)
pip install opencv-python==4.10.0.84

Q: Camera not recognized?

                **Check:**

• Windows Settings → Privacy → Camera permissions enabled for Python

• Test camera with Windows Camera app

• Modify VideoCapture(0) to VideoCapture(1) or 2

Q: Firmware upload failed?

                **Check:**

• Board selection correct: ESP32 Dev Module

• Port selection correct

• Hold BOOT button while uploading (if auto-reset fails)

• Reduce upload speed: 115200 → 57600

Q: GUI won't start?

# Verify Python version
python --version  # Must be 3.10

# Verify PySide6
python -c "import PySide6; print(PySide6.__version__)"

# If error, reinstall
pip uninstall PySide6
pip install PySide6

3. Motion Issues

Q: Robot arm position inaccurate?

                **Possible Causes:**

• Arm length parameters incorrect

• Step loss occurred

• Motor current too low

              **Solutions:**
  

• Re-measure arm lengths: Use calipers to measure, update robotGeometry.cpp

• Increase current limit: Slightly turn A4988 potentiometer clockwise

• Reduce acceleration: Decrease F value in GCode (e.g., G1 X10 F500)

Q: Movement stuttering or non-uniform?

                **Check:**

• Ball joints too tight (manual rotation should be smooth)

• A4988 microstep setting (recommended 16 microsteps)

• Mechanical friction in arms (lubricate ball joints)

Q: Out of range error?

                **Cause:** Target coordinates beyond workspace

                **Workspace limits:**

• Radial: R ≈ 100mm (center to XY plane distance)

• Z-axis: -320mm ~ -140mm (relative to base)

              **Solution:** Check target coordinates within limits
  

Q: Homing inconsistent position each time?

                **Check:**

• If using limit switches, check if triggered reliably

• If using HOME_STEPS, ensure motors don't skip steps

• Add mechanical end stops for consistent reference

4. Vision Issues

Q: YOLOv8 detection inaccurate?

                **Optimization:**

• Improve lighting: Avoid strong shadows, use uniform lighting

• Calibrate camera: Run checkerboard calibration to correct distortion

• Adjust confidence threshold: In code: model(frame, conf=0.5)

• Train custom model: Collect your object dataset for training

Q: Coordinate transformation large error?

                **Re-calibration Steps:**

• Re-mark 4 or more calibration points on workspace

• Accurately record pixel and physical coordinates

• Regenerate homography_matrix.npy

• Verify with known position objects

Q: Video stream lagging?

                **Optimization:**

# Reduce resolution
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 640)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 480)

# Lower frame rate
cap.set(cv2.CAP_PROP_FPS, 15)

# Use smaller YOLOv8 model
model = YOLO('yolov8n.pt')  # nano (fastest)

Still Can't Solve the Problem?

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• Email Support (service@nenpower.com)

• Community Forum

• Email: service@nenpower.com