Laser Engraver Blogs

Nano Duo allows precise color engraving on stainless steel by forming oxide layers or thin-film interference colors. Using the LaserBurn software, users can easily test and determine optimal engraving parameters to achieve the desired colors on stainless steel. This guide covers material preparation, parameter testing, layer-based color engraving, and practical use cases.

Stainless Steel Color Engraving Principle

Color formation by laser:

When stainless steel is heated by a laser, colored oxides or a transparent oxide film form on its surface. Thin-film interference causes various colors to appear. Oxidation products of metallic elements also contribute to the coloration.

Oxide color

Oxidation products of stainless steel elements naturally display color.

Oxide thin film interference

Under suitable laser energy, a colorless transparent oxide film forms on the surface, producing optical interference and resulting in various colors.

Material Preparation

Software: LaserBurn

Machine: Nano Duo

Material: Stainless Steel

File: Color Engraving File

Note: Material testing is required before engraving to obtain optimal parameters.

Use Cases

Medical devices, decorative items, automotive marking, architectural decoration, etc.

How do I use Nano Duo to test parameters for different colors on stainless steel?

This color engraving parameter guide is based on the Longer Nano Duo model machine, using stainless steel as the metal material. Utilizing the "Material Test" function in the LaserBurn software, the preparation of engraving parameter test files is greatly simplified. Users can input relevant parameter ranges in the "Material Test Generator" to automatically generate test files. Key parameters include power, speed, interval, and number of engraving passes; these combinations directly affect the engraved color. By setting appropriate parameter ranges according to the specific dimensions of the material, users can generate corresponding engraving test files.

Operating procedures:

Step 1

Open LaserBurn and ensure the device is successfully connected to the software (click "Device" in the upper right corner—"Connect"—select "Nano Duo"—click "Confirm").

(Connection page)

(Operation page in connection)

(Page after successful connection)

Step 2

Draw a 10×10 mm square on the canvas and set it to Fill mode. Click "Array" in the toolbar and select "Material Test." A parameter matrix interface will appear.

Recommended parameter range for Nano Duo:

Power: 50% to 100%

Speed: 1000 mm/min to 3000 mm/min

Matrix layout: 10×10

Ensure all parameters are correct, then click Confirm to create the test file. Finally, click Device → Engraving → Laser Focus (two points coincide) → Frame → Start Engraving, and wait for completion.

After the engraving test is completed, the system will generate a color matrix (as shown in the figure). Users can select the desired color from the matrix and find the corresponding laser power and speed. The horizontal axis of the matrix represents the power parameter, and the vertical axis represents the speed parameter. Users can easily determine the required engraving settings by matching the coordinate positions.

How to create colorful sculptures

As shown in the image, we import the image and perform a layer split on the vector image:

Step 1

First, select the part of the vector image to be sculpted.

Step 2

Click the bottom right corner to set layer 1.

Step 3

As shown in the image, we set the leaf part as a layer.

Step 4

Next, set the second layer.

Step 5

As shown in the image, select the center part of the letter.

Step 6

Then, set the 3rd layer.

Final Result

Finally, we obtain the complete layered vector of the material, as shown in the figure. Then we match the corresponding parameters for the desired colors. After completion, the engraving will produce the ideal color image.

We eventually received a colored badge.

Conclusion

By properly testing and setting parameters, the Nano Duo can achieve high-quality color engraving on stainless steel. Users can adjust power, speed, interval, and passes to achieve the desired color effects. This method is suitable for decorative items, metal signage, and other precision applications, providing a reliable solution for stainless steel color engraving.

Introduction

The NanoDuo Visual Correction function is designed to improve engraving accuracy by using the machine’s built-in camera to align the engraving position with the working area. By calibrating the camera and the laser workspace, the system can automatically adjust the engraving placement based on the captured image.

Before using the NanoDuo's several vision-related features for the first time, you'll need to perform visual alignment. This involves sculpting a target marker pattern and then marking it in the photo sent by the camera. Before starting, ensure that no other apps are using the NanoDuo's camera.

Precautions

• Place the engraving paper in the engraving work area (use the provided white engraving paper).

• When using the vision correction function, ensure no other cameras are connected and that the machine's camera is not in use.

• Do not move the machine or the engraving paper during the vision correction process. Ensure the correction process is completed in one go.

• Do not reuse the engraved pattern for correction; a new marking pattern must be engraved.

Engraved Marking Graphics

You will use your laser to engrave a target pattern on a piece of material and mark the center of the target.

1. first step

After connecting the nanoDuo, click the camera icon that appears in the menu bar to enter the vision correction function page.

Before entering the visual correction function page, please scale the canvas and move it to the side so that the entire canvas can be seen properly after the visual function page is opened.

2. Step 2

Enter the appropriate speed and power settings to achieve moderate engraving without burning through, and increase or decrease the scaling value until the canvas can accommodate the marked pattern.

3. Step 3

Click the Border Preview button to display the marker pattern on the canvas, ensuring it does not exceed the canvas size.

Note: Each time you modify the speed, power, and scaling values, you need to click the border preview button again to update the marker pattern on the canvas.

 4. Step 4

Click Start. If it's not clear enough, you can adjust the settings and run it again. When the pattern is clear and easy to see, click Complete. You may need to wait a few seconds on this screen for the camera to successfully capture your image.

Introduction

This document summarizes the common causes and solutions for CH340 driver installation issues on both Windows and macOS systems. It explains how to resolve problems related to system compatibility, driver conflicts, permission restrictions, USB cable issues, and security settings. It also provides methods to verify whether the driver is installed correctly and suggests alternative solutions if installation continues to fail.

By following the troubleshooting steps in this guide, users can quickly diagnose driver installation problems and restore normal communication between their device and computer.

Windows System

Common Causes and Solutions

1. System Compatibility Issues

Windows 10 and Windows 11 usually include a built-in driver for the CH340 chip. However, automatic installation may occasionally fail.

Solution

Download and install the latest driver manually from the official website:
https://www.wch.cn

Install the latest version of the driver package CH341SER.EXE.

2. Old Driver Conflicts

If an older version of the CH340 driver was previously installed, it may conflict with the new installation.

Solution

1. Open Device Manager.

2. Click View → Show hidden devices.

3. Expand Ports (COM & LPT).

4. Right-click any CH340/CH341 related devices and uninstall them.

5. Select Delete the driver software for this device if prompted.

6. Reinstall the latest driver.

3. Driver Signature Issues

Some systems, especially Windows 7 and certain Windows 10 configurations, may block unsigned drivers.

Solution

1. Restart your computer.

2. Enter Advanced Startup Options.

3. Select Disable driver signature enforcement.

4. Run the driver installer again.

4. Insufficient Permissions

Installing drivers requires administrator privileges.

Solution

Right-click the installer and select Run as administrator.

5. USB Cable or Port Problems

Some USB cables only support charging and do not transfer data. If such a cable is used, the device will not be recognized even if the driver is installed.

Solution

• Use a USB cable that supports data transfer.

• Connect the cable directly to the computer’s USB port (preferably USB 2.0).

How to Confirm the Driver Installation

1. Connect the Longer laser engraver to your computer.

2. Open Device Manager.

Under Ports (COM & LPT) you should see something similar to:

USB-SERIAL CH340 (COM3)

If this appears, the driver has been installed successfully.

If a yellow warning icon appears, the driver installation may have failed or there may be a driver conflict.

Alternative Solutions

If the driver still cannot be installed:

• Try using another computer to rule out system-related issues.

• Replace the adapter module with FT232 or CP2102, which often offer better compatibility.

macOS System

1. Check Whether a Driver Is Needed

Starting from macOS 10.13, the CH340 chip may sometimes be recognized automatically without installing a driver.

1. Connect your Longer laser engraver.

2. Open Terminal and enter:

ls /dev/tty.*

If you see a device such as:

/dev/tty.wchusbserial1410

The device has been detected successfully and no driver installation is required.

2. Install the Driver (If the Device Is Not Recognized)

Download the Driver

Official driver
https://www.wch.cn/downloads/CH341SER_MAC_ZIP.html

Open-source driver (recommended)
https://github.com/adrianmihalko/ch340g-ch34g-ch34x-mac-os-x-driver

The open-source version often provides better compatibility with newer macOS systems.

Allow System Extensions

During installation, macOS may display a message such as “System Extension Blocked.”

To allow the driver:

1. Open System Settings / System Preferences.

2. Go to Security & Privacy.

3. Under the General tab, click Allow for WCH Electronics Co., Ltd.

Restart Your Computer

After installation, restart your Mac so the driver can be loaded correctly.

Troubleshooting Common Issues

Driver Installed but No Port Appears

Open Terminal and run:

ls /dev/tty.*

Disconnect and reconnect the USB cable to check whether a new device appears.

Apple Silicon Macs (M1 / M2 / M3)

Many official drivers were originally designed for Intel-based Macs, which may cause compatibility issues on Apple Silicon devices.

For better stability, we recommend using the open-source driver from GitHub mentioned above.

Permission Restrictions on New macOS Versions

Recent macOS versions such as Big Sur, Monterey, and Ventura enforce stricter security policies for third-party drivers.

If the Allow option does not appear in Security & Privacy, you may need to:

1. Restart your Mac in Recovery Mode.

2. Temporarily disable System Integrity Protection (SIP).

3. Install the driver again.

Alternative Options

If you still cannot install the CH340 driver, you may consider these alternatives:

• Use an FTDI USB-to-serial module, which macOS supports natively without additional drivers.

• Use a Wi-Fi connection if your GRBL controller board supports wireless communication.

Nano Pro can be used for color engraving tests on stainless steel materials. By adjusting parameters such as power, speed, interval, and number of passes, different color effects can be achieved on stainless steel surfaces.

This article introduces the principles of stainless steel color laser engraving using Nano Pro, parameter testing methods, layered engraving workflow, and important precautions. By adjusting power, speed, interval, and passes, different color effects can be achieved on stainless steel surfaces.

1. Principle of Laser Color Engraving

The technical principle of color laser engraving varies depending on the material, but it mainly relies on two core methods: one is generating color naturally through oxidation reactions; the other is achieving the desired color effect through coloring agents.

For stainless steel color engraving, the technology is mainly divided into two categories. The first is that the laser beam instantly heats the metal surface, triggering physical or chemical reactions with the surrounding environment, thereby changing the surface color. The second is that the laser forms colored oxides on the metal surface or generates a transparent oxide film, producing various colors through thin-film interference effects.

By precisely adjusting key parameters such as laser power, engraving speed, interval, and passes, the reaction depth on the metal surface can be effectively controlled, achieving various color effects to meet different process requirements.

2. Stainless Steel Color Engraving Parameters

2.1 How to Test Different Color Parameters on Stainless Steel Using Nano Pro

The color engraving parameters in this example are based on the LONGER Nano Pro model, using stainless steel as the material.

With the "Material Test" function in LightBurn, the preparation of engraving parameter test files is greatly simplified. Users only need to enter the relevant parameter ranges in the "Material Test Generator" to automatically generate the test file. Key parameters include Power, Speed, Interval, and Passes. The combination of these parameters directly affects the final engraved color. By setting appropriate parameter ranges according to the material size, the corresponding test file can be generated.

The operation process is shown in the figure: first, start LightBurn, import the configuration file, select the correct serial port, and load the Nano Pro machine configuration. When the console displays "Nano Pro connected successfully," click "Laser Tools" in the toolbar to continue.

In the second step, after clicking "Laser Tools," select "Material Test." A matrix parameter setting interface will appear. Set the required matrix parameters in this interface. For Nano Pro, the recommended parameter range is Power 50%–100%, Speed 1000mm/min–3000mm/min, with an 11×11 matrix layout. After confirming the settings, click "Start" to begin the engraving test.

After completing the test, a color matrix will be generated. Users can select the desired color and find the corresponding power and speed parameters. The horizontal axis represents power, and the vertical axis represents speed. By matching the coordinates, the required settings can be determined.

2.2 How to Engrave a Color Artwork

Open LightBurn, click File → Import to load the layered image file, then connect to the Nano Pro machine.

After importing the image, perform layer processing on the vector graphic:

1) Select the vector section to be engraved.

2) Click the lower right corner and assign it to Layer 1.

3) As shown in the figure below, we set the butterfly section as a layer.

4) Then assign it to Layer 2.

5) Select the inner part of the butterfly.

6) Assign it to Layer 3.

After completing the layer separation, assign the corresponding color parameters to each layer. Once finished, start engraving to obtain the desired color result.

The final result is a blue butterfly.

3. Notes for Nano Pro Stainless Steel Color Engraving

3.1 Minimum Power

Important: When engraving stainless steel with Nano Pro, the power must remain above 50%. Power below 50% will result in very light coloration, mainly producing a single yellow tone. Engraving results are closely related to laser power, so precise adjustment is essential for achieving the desired color.

3.2 Minimum Stainless Steel Thickness and Surface Finish

During engraving, stainless steel plates that are too thin may deform due to heat accumulation. It is recommended to use stainless steel plates with a thickness of no less than 2 cm. Matte or brushed stainless steel surfaces are recommended for better engraving results. Industrial-grade or mirror-finish stainless steel is not recommended.

Common stainless steel surface finishes are shown below.

3.3 Ensure Level Positioning During Engraving

When using the recommended engraving parameters, ensure accurate laser focus and keep the Nano Pro machine level. Incorrect focus height will directly affect color uniformity and accuracy. Therefore, always calibrate the focus height before each operation.

Conclusion

By following the above methods, color engraving can be achieved on stainless steel using Nano Pro. Proper parameter testing, correct layer setup, and attention to power and material requirements are the key factors for obtaining stable color results.

Introduction

The Batch Fill function is designed to improve engraving efficiency by automatically identifying and copying a selected pattern onto multiple materials with similar contours. Using the camera to capture and recognize material outlines, the system replicates the design across all qualified objects in a single operation, ensuring consistent positioning and alignment.

Material Requirements

To ensure accurate recognition and proper batch placement, materials must meet the following conditions:

• All materials must be identical in shape, color, and material type.

  • Dimensional variation between targets must not exceed 10%.

  • Area variation must not exceed 25%.

• The material color must be clearly distinguishable from the background for accurate contour detection.
  

• Materials with highly reflective or glossy surfaces are not recommended.

• At least two or more materials must be fully visible and placed within the effective engraving area.

  • Minimum spacing between objects must be 5 mm.

• Material thickness must be less than 5 mm.

Precautions Before Use

• Ensure the camera function is operating properly before starting.

• Select the specific element(s) you want to batch fill.

  • The system will automatically remove any unselected elements before performing the batch operation.

• You must manually place the first pattern onto one material surface.

  • The batch fill process will replicate this pattern based on its position and angle.

• Keep the base plate clean, free of debris, dust, or scratches to ensure accurate detection.

Batch Filling Process

1. Place the Materials

1. Place materials of the same size, shape, and color on the base plate.

   • Maintain spacing greater than 5 mm between objects.

2. Ensure all materials are positioned within the effective engraving range.

• Figure 1: Correct placement

• Figure 2: Incorrect placement – objects too close together

• Figure 3: Incorrect placement – objects overlapping

• Figure 4: Incorrect placement – objects of different shapes

2. Capture Material Image

• Click Capture to take a photo of the materials and generate the contour outlines.

3. Set the Design Position

1. Create or import your design on the canvas.

2. Drag the design onto one material, ensuring it is fully positioned within the material boundary.

4. Batch Copy and Place Patterns

• Select the positioned design and click Batch Fill.

• The system will automatically detect the remaining material outlines.

• The design will be copied to each recognized object at the same relative position and angle.

5. Start Engraving

1. Adjust the appropriate material parameters.

2. Follow the normal engraving workflow.

3. Start the job to engrave all patterns on the canvas simultaneously.

Introduction

This guide explains how to use and calibrate the built-in camera function of the Nano Duo in LightBurn. Proper camera calibration ensures accurate visual positioning, improves engraving precision, and minimizes alignment deviations between the on-screen design and the actual engraved result.

Required materials: red cardstock, calibration card.

1. Open the LightBurn software, connect the Duo device, and then click Galvo Engraving Mode → BL 450 nm. (The connection is considered successful only if the following device information is displayed in the console.)

The above applies to versions below 2.0.00

The above applies to versions 2.0.00 and above.

2. Click Laser Tools → Calibrate Camera Lens in the upper left corner.

The above applies to versions below 2.0.00

The above applies to versions 2.0.00 and above.

3. Once you are on the Calibrate Camera Lens homepage, select USB Camera (the built-in camera).→ Standerd Lens→Next

The above applies to versions below 2.0.00

The above applies to versions 2.0.00 and above.

4. After proceeding to the next page, capture the images in the order of ①②③④ shown in the top left image, repeating this process nine times in different directions before proceeding to the next step of visual alignment. (If you proceed directly to visual alignment without performing visual calibration, engraving deviations may occur.)

Error demonstration: Overexposure, too bright

Correct demonstration

5. The following message indicates that the visual calibration operation has been completed. Please click "Align Camera" to enter the visual alignment page.

(1) The first method to access the visual alignment page

(2) The second method to access the visual alignment page

6. Remove the calibration card here, then select USB Camera (the built-in camera) and click Next.

7. In the parameter settings page, the necessary parameters to adjust are Fill Speed and Fill Power, as well as Line Speed and Line Power.7. After setting up, click Frame → Start, and then click Next when the sculpting is complete.

8. On this page, click Capture Image → Next.

9. Double-click the center point of the graphic in the order of 1, 2, 3, 4 until it looks like the second image, then click Next.

10. The following message indicates that the visual alignment operation has been completed.

11. Finally, verify if there are any obvious deviations, then return to the creation page→Window→Check Camera Control, and in the Camera Control page, select the camera module→Update Overlay

The above applies to versions below 2.0.00

The above applies to versions 2.0.00 and above.

12.Import the carving material, place it on the carving area in the canvas, and then click Frame (to confirm the carving position) → Start (to start carving).

13. After the carving is complete, click "Update Overlay" again to check if the carved position on the canvas matches the actual carved position. A deviation of 0.5-1 mm is normal. If the deviation is large, you need to repeat the visual alignment operation in step 7 above.)

Offline engraving on the Ray5 Series allows you to operate your laser projects directly from a TF card without connecting to a computer. This tutorial walks you through preparing GCode files, confirming engraving boundaries, and executing offline engraving for both old and new Ray5 models.

Table of Contents

1. What This Guide Covers
2. Quick Answer: How to Use TF Card for Offline Engraving
3. Why This Process Matters
4. Before You Start
   • Requirements
   • Precautions
5. Step-by-Step Tutorial
6. Model Version Differences
7. Common Problems and Solutions
8. Tips for Better Results
9. Frequently Asked Questions
10. Final Thoughts

What This Guide Covers

This guide provides a comprehensive walkthrough for performing offline engraving on Ray5 Series laser engravers. You will learn:

• How to prepare GCode files for offline use
• How to load and run engraving directly from a TF card
• Differences between old and new Ray5 models
• Tips for avoiding common errors and ensuring precise engraving

Quick Answer: How to Use TF Card for Offline Engraving

To perform offline engraving on the Ray5 Series:

1. Save your design as a GCode file (.gc or .nc) onto a TF card.
2. Insert the TF card into the Ray5 control box.
3. Access the file list via the File menu and select your design.
4. Verify the engraving boundary using Frame mode.
5. Start engraving and monitor the process.

Why This Process Matters

Offline engraving offers several advantages:

• Reduces dependence on a connected computer
• Avoids connectivity issues with USB or Wi-Fi
• Supports multiple projects simultaneously
• Provides consistent, repeatable results for professional-quality work

This method is ideal for both hobbyists and small businesses seeking efficient workflows.

Before You Start

Requirements

• Ray5 Series laser engraver (old or new version)
• TF card compatible with your machine
• Engraving file in GCode format (.gc or .nc)
• Safety equipment: laser safety glasses and proper ventilation

Precautions

• Only use TF cards recommended by the manufacturer
• Do not remove the TF card during engraving
• Confirm the machine’s working area before starting
• Keep fingers and other objects away from the laser head during operation
• Follow official machine specifications or instructions

Step-by-Step Tutorial

Step 1: Prepare Engraving File

Action: Save the engraving file in GCode format (.gc or .nc) to the TF card. Users can design patterns using LightBurn and export the GCode file directly to the TF card.
Expected Result: The TF card contains a ready-to-use engraving file.
Important Notes: Ensure the design dimensions fit the material and the machine’s working area.

Step 2: Start Offline Engraving

Action: Insert the TF card into the Ray5 control box and press File to access the TF card file list. Select the imported GCode file.

Expected Result: The file loads on the machine, ready for engraving.

Action: Enter the engraving preparation interface and click Frame to verify the engraving boundary.

Expected Result: The machine outlines the engraving area, confirming placement and size.

Action: After confirming the working area, press Start Engraving to begin the process.

Expected Result: The Ray5 laser engraves the selected design offline.

Important Notes: Interface layouts differ between old and new Ray5 models. Ensure you are following instructions corresponding to your version.

Model Version Differences

• Old Version Ray5: No air pump interface above the touchscreen

• New Version Ray5: Air pump interface located above the touchscreen

Understanding these differences helps ensure you navigate the interface correctly and avoid misconfigurations.

Common Problems and Solutions

Tips for Better Results

• Always use clean, properly formatted TF cards
• Secure material flat on the work area to prevent shifting
• Test engravings on scrap material before finalizing
• Keep lenses, mirrors, and the workspace clean
• Use adequate ventilation to minimize smoke residue

Frequently Asked Questions

Q1: Can I use any TF card with Ray5 Series?
A: Only use cards recommended by the manufacturer to prevent errors or device damage.

Q2: Do old and new Ray5 models operate the same offline?
A: Core steps are identical, but interface layouts and air pump placement differ.

Q3: What GCode formats are supported?
A: .gc and .nc files are supported for offline engraving.

Q4: How do I ensure the engraving fits the material?
A: Use Frame mode to preview the boundary before starting.

Q5: Can I pause offline engraving?
A: Yes, but never remove the TF card during operation.

Q6: Why is my TF card not recognized?
A: Ensure it is formatted correctly and compatible with the Ray5 Series.

Q7: Can I edit files on the machine?
A: Follow official machine specifications or instructions—editing on the device is not supported.

Final Thoughts

The Ray5 Series supports reliable offline engraving using a TF card. Properly preparing GCode files, verifying the engraving boundary, and understanding model differences ensures stable, professional-quality results. This method allows you to operate efficiently, minimize errors, and achieve consistent outcomes, making it ideal for hobbyists and small-scale production.

Video Tutorial

The Longer Laser Engravers are equipped with a powerful ESP32-based mainboard, which can offer high computing speeds and advanced features such as WiFi, Touchscreen Display, microSD slot and so on. In particular, Longer Ray5 has an MKS LTS mainboard, which offers excellent engraving speeds with precise adjustment of the laser module's power.

One of the main risks for the mainboard of Longer Laser Engravers is to manually move the motor axes. This action, in fact, generates a current that goes from the motors to the mainboard, damaging the stepper drivers irreparably. When this happens, the mainboard can no longer move the axle motors, and must be replaced. However, as mentioned before, the mainboard is based on ESP32, and therefore even if it is no longer suitable for use with Longer Ray5, it can still be useful for other projects.

The fact that the heart of the system is an ESP32 completely changes the perspective in the event of a driver failure. In a traditional mainboard, damage to the stepper drivers would mean total death of the component. With ESP32, on the other hand, we are faced with an open and versatile architecture that keeps its computational value intact. So even though the power section of the MKS LTS is compromised and can no longer handle PWM signals for the Longer Ray5 motors, the onboard microcontroller remains an amazing asset.

As with Arduino, ESP32 can also be programmed according to what you need most; it is possible, for example, to create an RF receiving station, a home automation control system, an anti-theft system, and so on. The only thing you need is writing proper C++ code.

Unlike a ready-to-use ESP32 board, on MKS LTS the pins are not directly indicated and ready to use, but must be identified among the various pins of the mainboard, as they are connected to the different functions in the design phase. For individuals, just use a function like:

int pins[] = {2, 4, 5, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 25, 26, 27, 32, 33};

int numPins = sizeof(pins) / sizeof(int);

 

void setup() {

  Serial.begin(115200);

  delay(1000);

  Serial.println("--- ACTIVE INVESTIGATOR MODE ---");

  Serial.println("Connect a wire to GND and tap the pins one at a time.");

 

  for (int i = 0; i < numPins; i++) {

    // We use INPUT_PULLUP for pins that support it

    // Note: 34, 35, 36, 39 don't have internal pullups, we will test them too

    if (pins[i] < 34) {

      pinMode(pins[i], INPUT_PULLUP);

    }

  }

}

 

void loop() {

  for (int i = 0; i < numPins; i++) {

    // If the pin reads LOW, you are touching it with GND

    if (digitalRead(pins[i]) == LOW) {

      Serial.print("FOUND! The pin you're tapping is the GPIO: ");

      Serial.println(pins[i]);

      

      // Wait for the wire to disconnect so as not to clog the serial

      while(digitalRead(pins[i]) == LOW) { delay(10); }

      Serial.println("---------------------------------------");

    }

  }

}

At this point, simply connect the respective pins to GND via a 10k pull-down resistor for safety, and the pin-detected will appear on consoles.

However, at the end of the detection procedure (which will take several hours) the available result pins are only these shown in the figure:

That is, the pins are available:

GPIO Main Function Usage notes

2 I/O Connected to Probe.

4 ADC2_CH0 / Touch General Purpose. Great for CSN - SPI communication.

18 VSPI SCK Great for SPI communication.

19 VSPI MISO Great for SPI communication.

23 VSPI MOSI Great for SPI communication.

33 ADC1_CH5 / Touch 8 General Purpose. Great for GDO0.

34 ADC1_CH6 Hardware pull-ups. Input only. 3.3V always present.

35 ADC1_CH7 Hardware pull-ups. Input only. 3.3V always present.

36 ADC1_CH0 Hardware pull-ups. Input only. 3.3V always present.

13 ADC2_CH4 HSPI communication connected to microSD.

14 ADC2_CH6 HSPI communication connected to microSD.

15 ADC2_CH3 / Strapping HSPI communication connected to microSD.

39 Solo Input Great for ADC1 but connected to microSD.

The GPIOs available are some of the best in ESP32, as you can use the SPI protocol with them, which allows you to do many useful things, such as using a CC1101 RF chip.

With the well-known GPIO pins, even a damaged MKS LTS becomes a valuable resource, to be used in a thousand different ways and just as many fun projects.

The Longer Laser Engravers are equipped with a powerful ESP32-based mainboard, which can offer high computing speeds and advanced features such as WiFi, Touchscreen Display, microSD slot and so on. In particular, Longer Ray5 has an MKS LTS mainboard, which offers excellent engraving speeds with precise adjustment of the laser module's power.

One of the main risks for the mainboard of Longer Laser Engravers is to manually move the motor axes. This action, in fact, generates a current that goes from the motors to the mainboard, damaging the stepper drivers irreparably. When this happens, the mainboard can no longer move the axle motors and must be replaced. However, as mentioned before, the mainboard is based on ESP32, and therefore even if it is no longer suitable for use with Longer Ray5, it can still be useful for other projects.

As seen in the previous article, once you understand that the Longer Ray5 mainboard is to all intents and purposes a powerful ESP32-based development board, and after identifying the location of the various GPIOs, the next step is to make it operational. To do this, the reference software is Arduino IDE, the environment that allows you to write and run C++ code on ATMEGA and ESP32 boards.

The first step is to download the latest stable version of the Arduino IDE from the official website (arduino.cc). By default, the Arduino IDE is configured for classic Arduino boards, so in order to see the ESP32 of MKS LTS you need to add the definitions of the Espressif boards.

In the Boards Manager, search for "ESP32" and click Install for the Espressif Systems package.

Once this has been done successfully, unlike a commercial board, MKS LTS does not appear with its specific name in the list. However, since it is based on a standard module, the correct configuration to select is "ESP32 Dev Module, with the following configuration:

Board: ESP32 Dev Module

Flash Mode: DIO

Flash Frequency: 80MHz

Upload Speed: 921600

At this point, power MKS LTS with 12V DC, and connect the mainboard to the PC via the USB cable. Select the COM port for the CH340 serial chip, and then run a test sketch. Once you click on Upload, keep an eye on the console: if the upload reaches 100%, the MKS LTS is officially reborn as a development board.

Keep in mind that in order to use the console, it is always necessary to set a delay of 5 seconds in each sketch, as shown in the figure:

Having the environment configured correctly is the only real barrier between a corrupted board and a working project. With the Arduino IDE ready and the GPIO pins already mapped, the limit is no longer the hardware that no longer moves the motors but only the complexity of the code you decide to write on it.

Introduction

When connecting your device to the LaserBurn software via USB, connection failures may occasionally occur due to cable issues, driver conflicts, power management settings, or system compatibility problems.

This guide provides a structured, step-by-step troubleshooting process—starting from simple physical checks to advanced system diagnostics—to help you quickly identify the root cause and restore a stable USB connection.

Stage 1: Quick Check and Basic Troubleshooting

These steps are the simplest and most often overlooked, but they often resolve the issue.

1. Reseat the USB cable:

Unplug the USB cable, wait a few seconds, then reseat it, ensuring it is fully inserted.

Purpose: Eliminate a momentary poor contact or software handshake failure.

2. Try a different USB port:

Unplug the USB cable from the current computer port and try another one (for example, from the front panel to the back panel).

Purpose: Eliminate a single USB port failure or insufficient power.

3. Restart the device and computer:

Shut down and restart both the device and computer.

Purpose: Clears temporary system caches and driver errors, a universal solution for various esoteric issues.

4. Check the physical connection:

Check the USB cable for visible damage or bends.

Check the device's USB port for loose connections, foreign objects, or damage.

Purpose: Eliminate the most basic physical layer issues.

5. Check if the USB port is occupied.

Stage 2: Software and Driver Troubleshooting

If basic troubleshooting doesn't work, the problem may lie with the software or driver.

1. Check the Device Manager:

On Windows, right-click "This PC" -> "Manage" -> "Device Manager."

Check for devices with a yellow exclamation mark (!) or question mark (?), especially under "Universal Serial Bus controllers" and "Other devices."

Action: If you see an unknown device or your device with an exclamation mark, right-click it and select "Update driver" -> "Search automatically for driver." If that doesn't work, try "Uninstall device" and then restart your computer to allow the system to automatically re-identify and install the driver.

2. Disable the USB selective suspend setting:

This is a power-saving feature that can sometimes cause unstable connections.

Path: Control Panel -> Hardware and Sound -> Power Options -> Change plan settings -> Change advanced power settings -> Find "USB settings" -> "USB selective suspend setting" -> Set it to "Disabled."

3. Check power management:

In Device Manager, expand Universal Serial Bus controllers, right-click each USB root hub, select Properties -> Power Management, and uncheck "Allow the computer to turn off this device to save power." Repeat this step for all USB root hubs.

Stage 3: In-depth hardware and system troubleshooting

If all of the above steps fail, you may need to consider more complex issues.

1. Replace the USB cable:

This is a very common problem! Many USB cables only charge, not transfer data. Be sure to use the original cable that came with your device or a high-quality USB cable that's proven to transfer data properly.

2. Test on another computer:

Connect your device to another working computer.

Result Interpretation:

If it works on the other computer: The problem lies with your original computer (driver, system, hardware port).

If it doesn't work on the other computer: The problem is most likely with your device or the USB cable.

3. Check the system log (Windows):

Right-click "This PC" -> "Manage" -> "Event Viewer" -> "Windows Logs" -> "System."

Check for error or warning logs around the time you plugged in the USB device; these logs will provide more specific error codes.

4. Update the motherboard chipset and USB controller drivers:

Go to the official website of your computer brand or motherboard manufacturer to download and install the latest chipset drivers. This can fundamentally resolve USB compatibility issues.