Reland Sun Load Cell and HX711 AD Converter Module User Manual

1. Introduction

The Reland Sun Load Cell and HX711 AD Converter Module is designed for precise weight and pressure measurement in various applications. This system combines a high-accuracy load cell with an HX711 analog-to-digital converter module, providing a reliable solution for electronic weighing scales, industrial control, and other measurement projects. This manual provides essential information for the proper setup, operation, and maintenance of your device.

2. Safety Information

• Handle electronic components with care to avoid damage from static discharge.
• Ensure correct wiring to prevent short circuits or component damage.
• Do not exceed specified voltage and current ratings for the HX711 module or the load cell.
• Keep the components dry and away from conductive materials.

3. Package Contents

Please verify that all items listed below are included in your package:

• 1 x Load Cell (e.g., 5kg capacity)
• 1 x HX711 AD Converter Module
• 1 x Pin Header (for HX711 module)

Figure 1: The complete set including a silver-colored bar-type load cell with four colored wires (red, black, white, green) connected, and a small green HX711 module with a black integrated circuit and a separate pin header.

4. Product Features

• High-precision 24-bit Analog-to-Digital (A/D) converter.
• Selectable gain of 32, 64, or 128 for different input ranges.
• Two selectable differential input channels.
• On-chip active low noise Programmable Gain Amplifier (PGA).
• On-chip power supply regulator for load-cell and ADC analog power supply.
• Simple digital control and serial interface for easy integration with microcontrollers.
• Load cell capacities available: 1kg, 5kg, 10kg, 20kg.

5. Specifications

6. Setup

6.1 HX711 Module Assembly

Solder the provided pin header to the HX711 AD converter module. Ensure proper orientation and secure connections.

Figure 2: Close-up of the green HX711 AD converter module, showing the integrated circuit, various surface-mount components, and the pin header next to it. The pins are labeled VCC, GND, DT, SCK, E+, E-, A+, A-, B+, B-.

6.2 Wiring the Load Cell to HX711 Module

Connect the load cell wires to the HX711 module according to the following standard color code for a full-bridge load cell:

• Red: E+ (Excitation +)
• Black: E- (Excitation -)
• White: A- (Output -)
• Green: A+ (Output +)

Note: Some load cells may use different color codes. Always refer to the load cell's specific documentation if available.

6.3 Connecting HX711 to a Microcontroller (e.g., Arduino)

The HX711 module requires four connections to a microcontroller:

• VCC: Connect to 5V or 3.3V power supply from the microcontroller.
• GND: Connect to ground (GND) of the microcontroller.
• DT (Data): Connect to a digital input pin on the microcontroller.
• SCK (Clock): Connect to a digital output pin on the microcontroller.

Ensure that the power supply voltage matches the operating voltage range of the HX711 module (2.6V - 5.5V).

7. Operating Instructions

7.1 Initializing the HX711 Module

To operate the HX711, you will typically use a microcontroller and a compatible library (e.g., HX711 library for Arduino). The library handles the communication protocol.

7.2 Calibration

Calibration is crucial for accurate weight measurements. The general steps are:

1. Tare: With no weight on the load cell, read the sensor value and set it as the zero point (tare).
2. Apply Known Weight: Place a known weight (calibration weight) on the load cell.
3. Calculate Scale Factor: Read the sensor value with the known weight. The difference between this reading and the tare reading, divided by the known weight, gives you the scale factor (e.g., counts per gram).
4. Save Calibration: Store the tare value and scale factor in your microcontroller's memory for future use.

7.3 Reading Weight

After calibration, you can read the current sensor value, subtract the tare value, and divide by the scale factor to get the measured weight.

8. Maintenance

• Keep the load cell and HX711 module clean and free from dust and moisture.
• Avoid applying excessive force or shock to the load cell, as this can damage its internal structure and affect accuracy.
• Periodically re-calibrate the system if you notice inconsistencies in readings or if the environment changes significantly.
• Ensure all wiring connections remain secure.

9. Troubleshooting

9.1 No Readings or Erratic Data

• Check Wiring: Verify all connections between the load cell, HX711 module, and microcontroller are correct and secure. Pay close attention to power (VCC, GND) and data (DT, SCK) lines.
• Power Supply: Ensure the HX711 module is receiving adequate power within its specified voltage range (2.6V - 5.5V).
• Microcontroller Code/Library: Confirm that your microcontroller code is correctly initializing the HX711 library and reading data. Ensure the correct pins are defined.
• Load Cell Integrity: Inspect the load cell for any visible damage or signs of stress.

9.2 Inaccurate Readings

• Recalibration: Perform a full calibration procedure as described in Section 7.2.
• Mechanical Interference: Ensure the load cell is mounted correctly and that there is no mechanical interference preventing it from accurately sensing weight. The object being weighed should only apply force to the load cell.
• Environmental Factors: Temperature fluctuations can affect load cell readings. Ensure a stable environment if high precision is required.
• Noise: Electrical noise can affect readings. Keep signal wires away from power lines and motors.

10. Warranty and Support

Information regarding warranty and specific support contacts for the Reland Sun Load Cell and HX711 AD Converter Module is not available in the provided product data. For details concerning warranty coverage, technical support, or replacement parts, please refer to your original purchase documentation or contact the seller directly through the platform where the product was acquired.