Original GroundStudio Product

Downloads:

Schematic and Layout

Product Description:

The HX711 integrated circuit module can be used to communicate with two load cells. Load cells are used to weigh objects in both industrial applications and for smaller weights.

The module is a high-precision, 24-bit device that communicates with Arduino development boards via a two-wire protocol (clock and data lines).

With two of these modules and four load cells, you can build your own scale.

The presence of power supply voltage is indicated by the "PWR" LED located on the module.

For applications requiring minimal power consumption, the "PWR" LED can be disabled using the "Disable PWR LED" jumper on the back of the PCB.

On the back of the PCB, there is also a "Sample rate" jumper that controls the data output transfer frequency. The jumper is closed by default (10Hz) and can be opened with a cutter (changing the frequency to 80Hz).

*The HX711 datasheet is available in PDF format in the Downloads section.

Technical Specifications:

Power supply voltage: 2.7V - 5.5V;

Current: 10mA;

ADC resolution: 24-bit;

2 channels;

Differential input.

Pinout:

• VCC = Main power supply (2.7V - 5.5V).
• VDD = Connected directly to VCC.
• DAT = Data transfer pin connection
• CLK = Clock signal pin connection.
• GND = Ground connection.
• YLW/SHIELD = Shield connection (if available, this pin is internally connected to GND).
• GRN/A+ = Positive analog input for channel A
• WHT/A- = Negative analog input for channel A
• BLK/E- = Ground connection for the load cell.
• RED/E+ = Analog power supply for the load cell.
• B+ = Positive analog input for channel B.
• B- = Negative analog input for channel B.

Arduino IDE Connection Example:

For this example, you will need the following:

1x HX711 GroundStudio weight sensor reading module | Reference IEYOLZ_AAA

1x Weight sensor | Reference DIXSZE_load-cell-1kg

1x GroundStudio Jade U1 development board | Reference RZUJBN_AAA

1x 1000-gram weight for calibration (should match the sensor's maximum capacity for accurate calibration).
Various wires for electrical connections and fixtures for the load cell/sensor (screws, support, and scale surface).

Step 1 - Diagram for establishing physical connections.

The load cell/sensor should be mounted as shown below:

Step 2 - Download Arduino IDE

Arduino IDE

Before connecting the board, download Arduino IDE 1.8.x from the link above, depending on your preferences and operating system.

Step 3 - Connect Jade U1 to your computer

After the initial connection via a USB-C cable, your computer will attempt to locate a compatible driver. The Jade U1 will connect directly to Windows via the HT42B534-2 chip, as its drivers are installed automatically.

Step 4 - Set up Arduino IDE.

To select the board, go to the "Tools" menu, click on the board option, and ensure Arduino Uno is selected.

Next, specify the Arduino IDE serial port to which Jade U1 is connected. Go to "Tools" again, hover over Serial Port, and select the COM port for Jade U1.

If multiple ports are available and you're unsure which one is Jade U1, temporarily disconnect the board and check which port disappears from the menu.

Step 5 - Install the necessary library for the HX711 module.

For the following code, install the HX711 library by Rob Tillaart.

This library can be installed directly in Arduino IDE by navigating to Tools -> Manage Libraries... and searching for "hx711".

Step 6 - Upload an example code.

After installing the library, go to File -> Examples -> HX711 and open "HX_kitchen_scale".

In this example, we used a 1000-gram weight. If using a sensor with a different capacity, use a weight equal to the sensor's maximum value for calibration. Modify line 43 in the code accordingly (you can also optionally change the string on line 39 to display "Put X gram in the scale, press a key to continue"):

Open the serial monitor, set the baud rate to 115200, and press the reset button on the development board.

The current sensor reading will be displayed:

UNITS: value
Empty the scale, press a key to continue

Ensure the scale is empty, then press the ENTER key in the "Message" section of the serial monitor (top).

The current sensor reading will display:

Put 1000 gram in the scale, press a key to continue

Place the 1000-gram weight on the sensor, then press ENTER again in the "Message" section of the serial monitor.

Package Contents:

1x HX711 GroundStudio weight sensor reading module

2x 1*5 male pin headers

1x 1*2 male pin header

NOTE: The included pin headers are not soldered, and soldering services are not provided for these.

Certifications:

Open Source Hardware Association