Gripper Controller Troubleshooting Guide

Common troubleshooting - quickly locate and resolve software and hardware issues

简体中文 | English | Support: support@genrobot.ai

Issue List

Type	Issue	Suggested Action
Software	Gripper cannot fully close after the target value is set to 0	Calibrate the motor stroke
Software	Encoder feedback is unstable or remains unchanged for a long time	Power-cycle and run zero-position calibration
Software	Serial port cannot be detected	Remove brltty and reboot
Software	Gripper feedback value is -66.66	Release the mechanical jam
Software	V4 camera frame rate is halved	Update the camera firmware
Software	640×480 resolution has obvious wavy jagged image artifacts	Update the camera firmware
Software	Device keeps restarting after tactile gripper heads are installed	Set the control frequency to 30 Hz
Software	Distance accuracy is inaccurate	Check mechanical play and recalibrate
Software	Why tactile data is expanded from 224 points to a 50×10 image	Restore the original sensor spatial layout for visualization and downstream processing
Hardware	Gripper can be moved by hand when powered on	Return for repair or use remote repair guidance
Hardware	One side moves after the gripper is powered on	Tighten front-cover screws or return for repair

1. Software Issues

1.1 Gripper cannot fully close after the target value is set to 0

Symptom

After the gripper target value is set to 0, the gripper still cannot fully close.

Cause

1. Mechanical play exists in the gripper.
2. No obvious mechanical play exists, but the motor stroke has not been calibrated, so the zero position is inconsistent with the mechanical closed position.

Solution Steps

1. Remove the front shell, tighten the linkage-related screws, and then calibrate the motor stroke.
2. Calibrate the motor stroke by running one of the following commands:

# ROS SDK
bash camera_cmd.sh left 1234

# Python SDK
python3 scripts/camera_cmd.py left 1234

Verification

During calibration, the gripper opens first and then closes. After closing is complete, calibration is finished. Power off and power on again to resume normal use.

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1.2 Encoder feedback is unstable or remains unchanged for a long time

Symptom

The encoder feedback value is unstable or remains unchanged for a long time.

Cause

This can occur when either the motor power port or the USB port is powered off and then powered on independently.

Solution Steps

1. Power-cycle the device

After each power-off, both the motor power port and the USB port must be powered on again.

2. Zero-position calibration

When the gripper is fully closed and then opened by about one third, run the following command. Send the command only once:

# ROS SDK
bash camera_cmd.sh left DMZEROSET

# Python SDK
python3 camera_cmd.py left DMZEROSET

Note
After calibration is complete, the motor must be powered on again.

Verification

After power-cycling, encoder feedback should change in real time as the gripper opens and closes.

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1.3 Serial port cannot be detected

Symptom

The system cannot detect the serial device corresponding to the gripper.

Cause

The brltty service occupies the serial port and intercepts the device.

Solution Steps

sudo apt remove brltty
sudo reboot

Verification

After rebooting, the serial device should appear in ls /dev/tty* or in the SDK device list.

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1.4 Gripper feedback value is -66.66

Symptom

The gripper feedback value remains fixed at -66.66, and the position cannot be read normally.

Cause

The internal gripper structure is stuck, so the encoder cannot complete normal power-on calibration.

Solution Steps

Gently move the gripper by hand in the opening direction to release the jam.

Verification

After the jam is released, the feedback value should return to the normal range and change as the gripper opens and closes.

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1.5 V4 camera frame rate is halved

Symptom

For V4, the actual camera frame rate is about half of the expected value, with a maximum of 30 fps.

Cause

V4 actively halves the frame rate to increase exposure time, so it cannot reach 60 fps.

Solution Steps

This issue can be resolved by updating the camera firmware. See 3. Camera Firmware Update.

Verification

After the firmware update, use the frame-rate test tool to verify that the camera can reach 60 fps.

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1.6 640×480 resolution has obvious wavy jagged image artifacts

Symptom

At 640×480 resolution, the image shows obvious wavy jagged artifacts.

Cause

The earlier firmware has a known image processing issue at this resolution. It can be fixed by applying the V2 camera firmware.

Solution Steps

This issue can be resolved by updating the camera firmware. See 3. Camera Firmware Update.

Verification

After upgrading to the fixed firmware, artifacts at 640×480 resolution should disappear or be significantly reduced.

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1.7 Device keeps restarting after tactile gripper heads are installed

Symptom

After tactile gripper heads are installed, the device restarts frequently.

Cause

The default control frequency is too high and causes system instability.

Solution Steps

After installing tactile gripper heads, adjust the control frequency to 30 Hz.

Verification

After the frequency is adjusted, the device should run stably without abnormal restarts.

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1.8 Distance accuracy is inaccurate

Symptom

The gripper distance feedback has unstable deviation from the actual distance.

Cause

During use, shaking the gripper while the motor is powered on and enabled can introduce mechanical play.

Solution Steps

If mechanical play is confirmed, remove the front shell and tighten the linkage screws.

Verification

After tightening the screws and recalibrating, the distance feedback should become stable.

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1.9 Why tactile data is expanded from 224 points to a 50×10 image

Question

Why not use the 224 tactile sampling points directly? Why expand them to 448 points first and then map them into a 50×10 image?

Cause

The physical tactile sensor array originally contains 500 sampling positions. Due to readout speed and real-time performance requirements, the device reduces the actual readout to 224 sampling points to lower data transfer and processing overhead.

Explanation

For tactile image display, algorithm processing, and alignment with the physical sensor positions, the data needs to approximate the original spatial layout of the tactile array. Therefore, the 224 sampled points are first expanded to a representation closer to the original array, and then mapped into a 50×10 tactile image. This step does not create new measured information; it makes visualization and downstream processing better match the sensor's physical arrangement.

2. Hardware Issues

2.1 Gripper can be moved by hand when powered on

Symptom

When the gripper is powered on, it can still be moved by external force.

Cause

The lead screw end stop is loose, so the motor cannot control the gripper.

Solution Steps

Return for repair or contact technical support for remote repair guidance.

For remote repair guidance, refer to the image steps below:

Final requirement:

Procedure:

Step 1
Tighten the pin.

Step 2
Tighten the clamp screws.

Step 3
Tighten the three motor bracket screws.

Step 4
Check the assembly and complete the remaining installation.

Verification

After repair, the gripper should not be easy to move by external force when powered on.

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2.2 One side moves after the gripper is powered on

Symptom

After the gripper is powered on, only one finger moves normally, while the other side does not respond.

Cause

The linkage is loose or broken, causing transmission failure.

Solution Steps

1. Remove the front cover. If any screws have fallen out, tighten them.
2. If the linkage is broken, return the device for repair.

For remote repair guidance, refer to the image steps below:

Final requirement:

Procedure:

Step 1
Loosen two screws.

Step 2
Support from below. Press the pin out with a blunt hard tool.

Step 3
After removing the pin, remove and replace the damaged large arm.

Step 4
First tighten the shoulder screw, then press the pin in from top to bottom. Avoid pinching wires.

Step 5
After tightening the screws, complete the remaining assembly.

Verification

After repair, both fingers should open and close synchronously.

3. Camera Firmware Update

This section covers camera-related fixes for Gripper Controller V4. Select the firmware version according to the symptom, then flash the center camera and side cameras in order.

3.1 Applicable Issues

Issue	Applicable Product Version	Recommended Action
1.5 V4 camera frame rate is halved	Gripper Controller V4	Use the V1 firmware to add the 60 fps configuration.
1.6 640×480 resolution has obvious wavy jagged image artifacts	Gripper Controller V4	Use the V2 firmware to fix 640×480 jagged ghosting artifacts.

3.2 Environment and Flashing Order

Item	Requirement
Operating system	Windows PC
Connection	Connect the Gripper Controller to the PC with a USB cable
Flashing order	Flash the center camera (camera0) first, then flash the side cameras (camera1, camera2)

3.3 Firmware Versions

V1 Firmware Update

Item	Description
Update reason	The actual frame rate of V4 cameras is about half of the expected value, with a maximum of 30 fps, because the exposure time was increased.
Version notes	Adds the 60 fps camera configuration.
Applicable product version	Gripper Controller V4
Applicable issue	1.5 V4 camera frame rate is halved

Camera Position	Firmware File
Center camera (camera0)	JZXC_WebCam_SPCA2680A_OG02B10m_BCD0225_202605112026_SCA_FSIN_5MP.bin
Side cameras (camera1, camera2)	JZXC_WebCam_SPCA2680A_OG02B10m_BCD0226_202605112030_SCA_FSIN_3MP.bin

V2 Firmware Update

Item	Description
Update reason	Jagged ghosting artifacts appear at 640×480 resolution.
Version notes	The V2 firmware is based on the V1 firmware and keeps the 60 fps configuration. The old firmware outputs 640×480 through sensor binning mode; V2 changes to Full Size output mode and uses ISP to scale down from 1600×1296.
Applicable product version	Gripper Controller V4
Applicable issue	1.6 640×480 resolution has obvious wavy jagged image artifacts

Camera Position	Firmware File
Center camera (camera0)	JZXC_WebCam_SPCA2680A_OG02B10m_BCD0232_202607061313_SCA_FSIN_5MP.bin
Side cameras (camera1, camera2)	JZXC_WebCam_SPCA2680A_OG02B10m_BCD0233_202607061315_SCA_FSIN_3MP.bin

3.4 Tool Downloads

Tool	Description	File
Firmware flashing tool	Used to flash camera firmware	TSTC_USB_Camera_Suite_Install_Package_Ver26.03.16.03.14.00.exe
Frame-rate test tool	Used to verify 60 fps	amcap v3.0.9.exe

3.5 Flashing Tool Instructions

Use the tool to select the device, firmware file, and start flashing. Click the image to view it at full size.

3.6 Center Camera Firmware Flashing Steps

The center camera is camera0. Select the center-camera firmware file that matches the firmware version you are applying.

3.7 Side Camera Firmware Flashing Steps

The side cameras are camera1 and camera2. Both side cameras use the same side-camera firmware file.

3.8 60 fps Verification

After flashing, disable the frame-rate limit first, then use the frame-rate test tool to verify 60 fps.

4. Still Unresolved?

If the steps above do not resolve your issue, contact support@genrobot.ai and provide:

• Issue number and symptom description
• Reproduction steps
• SDK version used (ROS / Python)
• Related command output or logs