Grove - ADC for Load Cell (HX711)

The Grove - ADC for Load Cell (HX711) is a 24-bit A/D converter designed specifically for the load cell. It contains an on-chip low noise programmable amplifier with an optional gain of 32, 64 and 128. The HX711 chip integrates a regulated power supply, an on-chip clock oscillator, and other peripheral circuits, which have the advantages of high integration, fast response, and strong anti-interference.

note

With the Grove connector and 4-pin screw terminal, it becomes quite easy to connect the load cell and microcontroller, no soldering required. You can build your own Arduino weigh sensor system in just a few simple steps.

Specifications

Item	Value
Battery	Exclude
Working voltage	2.6V--5.5V
Working current	Less than 1.5A
Detection accuracy	24 bits
Output date rate	10SPS or 80SPS
Optional gain	32 for Channel B/ 64 and 128 for Channel A

Application

Electronic scales
Price computing scales
Electronic platform scales
Digital scales
Parcel post scales

Hardware Overview

Platforms Supported

Arduino	Raspberry Pi

caution

The platforms mentioned above as supported is/are an indication of the module's software or theoritical compatibility. We only provide software library or code examples for Arduino platform in most cases. It is not possible to provide software library / demo code for all possible MCU platforms. Hence, users have to write their own software library.

Getting Started

In this part, we will use a Arduino UNO R4 WiFi as a controller,show how to use a Grove - ADC for Load Cell (HX711) and a Weight Sensor (Load Cell) 0-500g make a weight measuring module.

Hardaware Preparation

Step 1. Material preparation

Arduino UNO R4 WIFi	Grove - ADC for Load Cell (HX711)	Weight Sensor (Load Cell) 0-500g

Get One Now 🖱️	Get One Now 🖱️	Get One Now 🖱️

note

Weight sensor output 0V when the load less than 150g, it not directly measure the load .So it suggests using a 200g local avoid measure blind spot.Read the analog data of 200g weight as no-load(0g),read the analog data of 700g weight as full load(500g).
ADC for Load Cell (HX711) uses channel A by default, if you want to use other channels, it will require you to weld it yourself.

And the Grove - ADC for Load Cell (HX711) is also suitable for our XIAO development board.

Seeed Studio XIAO SAMD21	Seeed Studio XIAO RP2040	Seeed Studio XIAO nRF52840 (Sense)	Seeed Studio XIAO ESP32C3	Seeed Studio XIAO ESP32S3 (Sense)

Get One Now 🖱️	Get One Now 🖱️	Get One Now 🖱️	Get One Now 🖱️	Get One Now 🖱️

Step 2. Hardware Connection

Connect the Grove Gesture Sensor to the IIC port of Arduino UNO R4 WiFi, connect the Arduino to PC via a USB cable, and the connection bettewn Grove - ADC for Load Cell (HX711) and Weight Sensor (Load Cell) 0-500g is show below:

Grove - ADC for Load Cell (HX711)	Weight Sensor (Load Cell) 0-500
E+	Red
E-	Black
INA-	White
INA+	Green/Blue

tip

Using Grove Base Shield, you can directly connect HX711 module to Arduino UNO R4 WiFi as below.

Software Preparation

The recommended programming tool is the Arduino IDE, and you need to configure the Arduino environment for the XIAO and add the on-board package.

tip

If this is your first time using Arduino, we highly recommend you to refer to Getting Started with Arduino.

Step 1. Launch the Arduino application.

Download Arduino IDE

Step 2. Select your development board model and add it to the Arduino IDE.

If you want to use Seeed Studio XIAO SAMD21 for the later routines, please refer to this tutorial to finish adding.
If you want to use Seeed Studio XIAO RP2040 for the later routines, please refer to this tutorial to finish adding.
If you want to use Seeed Studio XIAO nRF52840 for the later routines, please refer to this tutorial to finish adding.
If you want to use Seeed Studio XIAO ESP32C3 for the later routines, please refer to this tutorial to finish adding.
If you want to use Seeed Studio XIAO ESP32S3 for the later routines, please refer to this tutorial to finish adding.
If you want to use Seeeduino V4.3 for the later routines, please refer to this tutorial to finish adding.
If you want to use Arduino UNO R4 WiFi for the later routines, please click Tools-> Board-> Boards Manager..., print keyword "UNO R4 WiFi" in the searching blank and install the latest version (or the version you want to use).

HX711 Arduino Library Overview

Function

Before we get started developing a sketch, let's look at the available functions.

void begin(byte dout, byte pd_sck, byte gain ) —— Initialize library with data output pin, clock input pin and gain factor.Channel selection is made by passing the appropriate gain, the library default is "128" (Channel A).
- Input Parameters:
  - byte dout： Passed as dout (converted to byte) HX711 circuit wiring.
  - byte pd_sck： Passed as pd_sck (converted to byte) HX711 circuit wiring.
  - byte gain = 128：
    - With a gain factor of 64 or 128, channel A is selected.
    - With a gain factor of 32, channel B is selected.
bool is_ready() —— Check if HX711 is ready. From the datasheet: When output data is not ready for retrieval, digital output pin DOUT is high. Serial clock input PD_SCK should be low. When DOUT goes to low, it indicates data is ready for retrieva.
void wait_ready(unsigned long delay_ms = 0); —— Wait for the chip to become ready.
bool wait_ready_retry(int retries = 3, unsigned long delay_ms = 0) —— Wait for the chip to become ready by retrying for a specified amount of attempts.
bool wait_ready_timeout(unsigned long timeout = 1000, unsigned long delay_ms = 0) —— Wait for the chip to become ready until timeout.
void set_gain(byte gain = 128) —— set the gain factor; takes effect only after a call to read().
- Input Parameters:
  - byte gain = 128： Channel A can be set for a 128 or 64 gain; channel B has a fixed 32 gain.
long read() —— waits for the chip to be ready and returns a reading
long read_average(byte times = 10) —— returns an average reading.
- Input Parameters:
  - byte times = 10: times = how many times to read.
double get_value(byte times = 1) —— returns (read_average() - OFFSET), that is the current value without the tare weight.
- Input Parameters:
  - byte times = 1: times = how many readings to do.
float get_units(byte times = 1) —— returns get_value() divided by SCALE, that is the raw value divided by a value obtained via calibration.
- Input Parameters:
  - byte times = 1: times = how many readings to do.
void tare(byte times = 10) —— set the OFFSET value for tare weight.
- Input Parameters:
  - byte times = 10: times = how many times to read the tare value.
void set_scale(float scale = 1.f) —— set the SCALE value; this value is used to convert the raw data to "human readable" data (measure units)
float get_scale() —— get the current SCALE
void set_offset(long offset = 0) —— set OFFSET, the value that's subtracted from the actual reading (tare weight)
long get_offset() —— get the current OFFSET
void power_down() —— puts the chip into power down mode
void power_up() —— wakes up the chip after power down mode

Installation

Download the Library

Since you have downloaded the zip Library, open your Arduino IDE, click on Sketch > Include Library > Add .ZIP Library. Choose the zip file you just downloaded，and if the library install correct, you will see Library added to your libraries in the notice window. Which means the library is installed successfull.

Example Demo

Step 1. Before the Grove - ADC for Load Cell (HX711) measuring, the PD_SCK should be pulled down to make it ready for work and the load cell should be calibrated.The Grove_ADC_for_Load_Cell_(HX711) example code is as follow:

#include "HX711.h"

// HX711 circuit wiring
const int LOADCELL_DOUT_PIN = 3;  //Set your I2C pin
const int LOADCELL_SCK_PIN = 2;


HX711 scale;

void setup() {
  Serial.begin(9600);
  Serial.println("HX711 Demo");

  Serial.println("Initializing the scale");

  // Initialize library with data output pin, clock input pin and gain factor.
  // Channel selection is made by passing the appropriate gain:
  // - With a gain factor of 64 or 128, channel A is selected
  // - With a gain factor of 32, channel B is selected
  // By omitting the gain factor parameter, the library
  // default "128" (Channel A) is used here.
  
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);

  Serial.println("Before setting up the scale:");
    if (scale.wait_ready_timeout(1000)) {
    long reading = scale.read();
    Serial.print("HX711 reading: ");
    Serial.println(reading);
  } else {
    Serial.println("HX711 not found.");
  }   // print a raw reading from the ADC

  Serial.print("read average: \t\t");
  Serial.println(scale.read_average(20));   // print the average of 20 readings from the ADC

  Serial.print("get value: \t\t");
  Serial.println(scale.get_value(5));       // print the average of 5 readings from the ADC minus the tare weight (not set yet)

  Serial.print("get units: \t\t");
  Serial.println(scale.get_units(5), 1);    // print the average of 5 readings from the ADC minus tare weight (not set) divided
                        // by the SCALE parameter (not set yet)

  scale.set_scale(2280.f);                      // this value is obtained by calibrating the scale with known weights; see the README for details
  scale.tare();                     // reset the scale to 0

  Serial.println("After setting up the scale:");

  Serial.print("read: \t\t");
  Serial.println(scale.read());                 // print a raw reading from the ADC

  Serial.print("read average: \t\t");
  Serial.println(scale.read_average(20));       // print the average of 20 readings from the ADC

  Serial.print("get value: \t\t");
  Serial.println(scale.get_value(5));       // print the average of 5 readings from the ADC minus the tare weight, set with tare()

  Serial.print("get units: \t\t");
  Serial.println(scale.get_units(5), 1);        // print the average of 5 readings from the ADC minus tare weight, divided
                        // by the SCALE parameter set with set_scale

  Serial.println("Readings:");
}

void loop() {
  Serial.print("one reading:\t");
  Serial.print(scale.get_units(), 1);
  Serial.print("\t| average:\t");
  Serial.println(scale.get_units(10), 1);

  scale.power_down();                   // put the ADC in sleep mode
  delay(5000);
  scale.power_up();
}

Step 2. Please click the Board selection dropdown menu, and then click on "Select other board and port...".

Step 3. And then search and select "Arduino UNO R4 WiFi".

Step 4. Please click "upload" to flash the firmware on to Arduino.

Step 5. Open the Serial Monitor of Arduino IDE by click Tool-> Serial Monitor. When you see serial print "After setting up the scale:", wait a few seconds and apply force to Weight Sensor (Load Cell) 0-500g.

Step 6. The result should look like below.

Resource

[PDF]INA125 datasheet

[PDF]HX711-datacheet

[ZIP]Grove - ADC for load cell (HX711)-Schematic File

Tech Support & Product Discussion

Thank you for choosing our products! We are here to provide you with different support to ensure that your experience with our products is as smooth as possible. We offer several communication channels to cater to different preferences and needs.

Grove - ADC for Load Cell (HX711)

Specifications​

Application​

Hardware Overview​

Platforms Supported​

Getting Started​

Hardaware Preparation​

Software Preparation​

HX711 Arduino Library Overview​

Function​

Installation​

Example Demo​

Resource​

Tech Support & Product Discussion​