1. Introduction
The Gauselink GL-R01 is a compact and lightweight Time Of Flight (ToF) Mini LiDAR Laser Ranging Sensor Module designed for precise distance and liquid level measurements. It offers multiple output types including UART Automatic, UART Controlled, and IIC, making it versatile for various applications with microcontrollers like Arduino. This manual provides essential information for the proper setup, operation, and maintenance of your GL-R01 sensor.
Figure 1: Gauselink GL-R01 ToF Sensor Module
The Time-of-Flight principle, on which this sensor operates, measures the time difference between the emission of photons and their reception after being reflected by a target. This allows for highly accurate distance measurements in millimeters.
Figure 2: Basic principle of a ToF sensor, showing emitted invisible laser light and reflected light used to calculate distance.
Video 1: Demonstration of the GL-R01 sensor's mini size, ultra-light weight (2.4g), Modbus protocol communication, and distance measurement capabilities with various objects (flat, glass, polybag, PVC tube) and against a wall, highlighting its small detection angle.
2. Specifications
2.1 Product Parameters
- Serial No.: GL-R01
- Type: Laser Ranging Sensor Module
- Light Source: 940nm infrared light (invisible)
- Blind Zone: 0 ~ 2cm (0~0.8")
- Output Types: UART Automatic, UART Controlled, Switch, IIC
- Output Connector: MX1.25 (4-Pin)
- Working Temperature: -15°C ~ 60°C
- Working Voltage: 3.3 ~ 5V DC
- Baud Rate: 115200 bits/second (default)
- Protection Level: IP67
- Net Weight: 2.4 grams
- Electrostatic Protection: Conforms to EMC Directive EN61000-6-1, IEC61000-4-2 standard.
2.2 Detailed Parameters for Different Outputs
Figure 3: Detailed parameters for UART Automatic, UART Controlled, Switch, and IIC output types.
Remarks:
(a) When the sensor doesn't receive any command and stays idle.
(b) Working cycle 100ms, Voltage 5V, Temperature 25°C, Humidity 65%RH.
(c) Temperature 25°C, Humidity 65%RH, Light Intensity <=700Lux. Object: White Paper Board Size 100cm*10cm. S is the distance measured.
(d) Outdoor Temperature 25°C, Humidity 65%RH, Natural Light, Object with Size 1m*1m and Reflection rate >=88%.
(e) Detectable angle if the object is Dia. 7.5*100cm White PVC Tube at distance 100cm.
2.3 Product Dimensions
The sensor is mini-sized and ultra-light, with a main diameter smaller than a 1 Euro cent coin and a weight of approximately 2.4 grams.
Figure 4: GL-R01 sensor size comparison with a 1 Euro Cent coin and its weight (2.4 grams).
Detailed dimensions are provided below (Unit: mm). The standard cable length is 150mm (5.9").
Figure 5: Detailed dimensional drawing of the GL-R01 sensor module and its MX1.25 connector.
2.4 ToF vs. Ultrasonic Sensor Comparison
The GL-R01 optical ToF sensor offers different characteristics compared to traditional ultrasonic sensors. Refer to the table below for a comparison of their performance in various environments and with different object characteristics.
Figure 6: Comparison of ToF and Ultrasonic sensor reliability in different environments and with various object characteristics. (⭐⭐⭐⭐⭐ - Excellent Performance, ⭐ - Poor Performance)
Note: It is not recommended to use the GL-R01 in sunny or excessively bright environments, as the maximum measurable distance may significantly decrease.
3. Setup and Installation
3.1 Package Contents
Each GL-R01 SKU includes:
- Laser Ranging Sensor x 1 Piece
- MX1.25 Connector with Cable x 1 Piece
Figure 7: GL-R01 sensor module and its MX1.25 connector cable.
3.2 Wiring Diagram and Interface Definition
The sensor uses an MX1.25 4-Pin connector. The interface definitions are as follows:
| Color | Pin No. | Name | Definition |
|---|---|---|---|
| Red | 1 | VCC | Connects to + of Power (3.3V-5V DC) |
| Black | 2 | GND | Connects to - of Power (Ground) |
| Yellow | 3 | RX | Connects to TX of Controller (MCU) |
| Green | 4 | TX | Connects to RX of Controller (MCU) |
Figure 8: Pinout and wiring diagram for the GL-R01 sensor.
3.3 IIC Output Specific Wiring
For IIC output, the SDA (green) and SCK (yellow) terminals must be separately connected to pull-up resistors. A resistance of 3kΩ to 10kΩ is recommended, with 3.9kΩ suggested for initial testing. These resistors are not included with the sensor.
Figure 9: IIC wiring diagram showing the connection of pull-up resistors to SDA and SCK lines.
3.4 Installation Hole Dimensions
The recommended distance between the two installation holes is 19mm.
Figure 10: Diagram illustrating the recommended dimensions for mounting holes (Unit: mm).
4. Operating Instructions
The GL-R01 sensor supports various output modes. Please refer to the specific subsection for your chosen output type.
4.1 UART Automatic Output
In UART Automatic mode, the sensor performs measurements autonomously without requiring a triggering signal. The TX terminal outputs distance data every 100ms by default. The cycle time can be adjusted via Modbus commands (refer to Section 4.3).
- If the RX terminal connects to a low level (GND), the response time is 100ms (default).
- If the RX terminal is suspended or connects to a high level, the sensor outputs a more stable, processed value. The response time in this case is 1 to 3 times the cycle time (i.e., 100-300ms).
Notes:
- When the output cycle time is set to 1000ms or more, the output will be a real-time value.
- The RX terminal detects the current level only within 800ms after power-on. After this initial period, no further detection occurs.
UART Output Data Format
Figure 11: Table detailing the UART output data format, including frame header, data bytes, and checksum calculation.
4.2 UART Controlled Output
In UART Controlled mode, the sensor requires a Modbus command as a triggering signal via its RX terminal. After receiving the command, the sensor performs a measurement, and the TX terminal outputs the data. The Modbus Protocol details are provided in Section 4.3.
Timing Diagram:
- T₁ > T₂ + 8ms
- T₂ = 19~38ms (for real-time value)
- T₂ = 170~260ms (for processed value)
- Recommendation: T₁ ≥ 50ms for real-time value (register 0x0101).
Figure 12: Timing diagram for UART Controlled output, illustrating the relationship between RX (Modbus command) and TX (data output) signals.
Communication Example
Figure 13: Example of UART Controlled communication, showing Modbus command (TX) and sensor response (RX) with calculated distance.
4.3 Modbus Protocol
RS485 Communication Parameters
- Data bit: 8
- Stop bit: 1
- Parity Check: None
- Default Baud Rate: 115200bps
Modbus Protocol Details
- Protocol: Modbus-RTU
- Verification: CRC-16
- Sensor Address: 0x01 by default (can be changed)
- Read Code: 0x03
- Write Code: 0x06
Figure 14: Modbus Protocol structure for Host (TX) and Sensor (Slave) Replies for Read and Write operations.
Modbus Registers
Figure 15: Table of Modbus registers, including read/write status, address, function, data type, and explanation.
Modbus Communication Examples
- To read processed value:
Host (TX):01 03 01 00 00 01 85 F6
Client (RX):01 03 02 02 F2 38 A1
Explanation: Sensor address is 0x01. Processed distance value is 0x02F2, which is 754mm in decimal. - To read real-time value:
Host (TX):01 03 01 01 00 01 D4 36
Client (RX):01 03 02 02 EF F8 A8
Explanation: Sensor address is 0x01. Real-time distance value is 0x02EF, which is 751mm in decimal. - To change client address:
Host (TX):01 06 02 00 00 05 48 71
Client (RX):01 06 02 00 00 05 48 71
Explanation: Sensor address is changed from 0x01 to 0x05. - To check sensor address (if forgotten, with only 1 sensor connected):
Host (TX):FF 03 02 00 00 01 90 6C
The sensor replies:
(RX):01 03 02 00 01 79 84
Explanation: This indicates the sensor address is 0x01. 0xFF is the broadcast address.
4.4 IIC (I²C) Output
The GL-R01 sensor with IIC output functions as a slave device, allowing multiple sensors to be connected in parallel. The communication level is 3.3V, and the communication speed ranges from 10 to 100k bits/s. The broadcast address is 0x00, and the default address is 0xE8.
IIC Timing Diagram
Figure 16: IIC timing diagrams for reading 1 byte, reading 2 bytes, and writing 1 byte of data. Note: The signal above is from the slave/sensor, and the signal below is from the host.
IIC Registers
Figure 17: Table of IIC registers, including read/write status, address, function, data type, and explanation.
5. Maintenance and Care
- Do not use the product in corrosive environments.
- Avoid strong noise near the sensors, as it may interfere with the signal transmission.
- Replace the product if it is deformed, damaged, or fails to operate properly.
- The housing is air-tightly sealed by glue, providing IP67 protection. This helps protect the internal circuit and extends the sensor's lifespan.
Figure 18: Illustration of the GL-R01 sensor's IP67 waterproof protection.
6. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Inaccurate readings or no output. | Incorrect wiring, power supply issues, environmental interference, sensor damage. | Verify all wiring connections (VCC, GND, RX, TX). Ensure power supply is within 3.3-5V DC. Check for strong noise sources. Inspect sensor for physical damage. |
| Reduced measurement range in bright conditions. | High ambient light (e.g., direct sunlight). | ToF sensors are sensitive to strong light. Avoid using in direct sunlight or very bright environments. Consider shielding the sensor or using it indoors. |
| Communication errors with UART. | Incorrect baud rate, data format, or Modbus commands. | Ensure your controller's UART settings (baud rate 115200bps, 8 data bits, 1 stop bit, no parity) match the sensor. Double-check Modbus commands and CRC-16 verification. |
| IIC communication issues with multiple sensors. | Missing pull-up resistors, incorrect slave addresses. | Ensure 3k-10kΩ pull-up resistors are connected to SDA and SCK lines. For multiple sensors, ensure each has a unique IIC address. The GL-R01 ToF sensor does not support RS485 for multi-sensor setups, but IIC can be used with different IDs. |
7. User Tips
- Multi-Sensor Setup: If you plan to use multiple GL-R01 ToF sensors, consider using the IIC output option. The IIC interface allows for setting different IDs for each sensor, enabling them to work together on the same bus. Note that RS485 (Modbus) is not an available option for multi-sensor ToF setups with this model.
- Cable Customization: The sensor comes with a 150mm (5.9") cable by default. If your application requires a longer cable, contact Gauselink for customization options.
- Environmental Considerations: While the sensor has IP67 protection, its optical nature means performance can be affected by extreme light conditions. For optimal accuracy, especially over longer distances, use in controlled lighting environments.
8. Warranty and Support
The GL-R01 sensor is manufactured in an ISO9001 certified factory, ensuring high quality and reliability. Each product undergoes strict testing and features a unique traceability code.
Figure 19: ISO9001 certification and product traceability code.
For technical support, customization projects, or any inquiries, please contact Gauselink's sales assistant online or via email: gauselin@163.com.
Figure 20: Gauselink customer support for customization and inquiries.
Manufacturer: Shenzhen Gauselin Technology Co., Ltd.
Address: No. 333, Qianhai Road, Nanshan, Shenzhen, Guangdong, China
This product complies with CE and RoHS standards.
For detailed item guides and documents, including the user manual in PDF format, please refer to the official product page or contact support.