HX711 Library

Table of Contents

• HX711 Library
  • Table of Contents
  • About
  • Getting Started
    • Installing
      • ESP-IDF
      • Platformio
  • Usage
  • Documentation
  • Todo

About

This library is for the hx711 modul to read weight load. It is build for esp-idf framework and written in C++!

Getting Started

Goal of this project is to provide an easy to use library for the hx711 modul written in C++!

The main featers are:

• Easy to use
• Reading value from hx711 modul in background task
• Create average value from x samples to get more accurate results
• Remove highest and lowest value to get more accurate results

Installing

ESP-IDF

The library contains a idf_compent.yml file. So you can install it with the esp-idf packagemanager to be aviable in your project.

To integerate it to your project create a file named idf_compent.yml and put following lines in it.

dependencies:
  idf: ">=4.4"

  hx711:
    git: https://github.com/avjui/hx711.git

📁 The file was also aviable in the example folder main dirctory.

After this installation is complete and you can build your project with th hx711 library.

Platformio

To use this library in platformio you can add lib_deps to your configuration file platformio.ini

lib_deps = 
    git+https://github.com/avjui/hx711

⚠️ Because platformio not regiester the Kconfig by him self you have to add Kconfig with editing CMakeLists.txt, or add the config variables to platfomrio.ini.

• First option is to add following lines to CMakeLists.txt in the root directory.

get_filename_component(configName "${CMAKE_BINARY_DIR}" NAME)
list(APPEND kconfigs "${CMAKE_SOURCE_DIR}/.pio/libdeps/${configName}/hx711/Kconfig")

• An other option is to add the config to platformio.ini.

[hx711]
; Build flags for hx711 library
build_flags=
    -D CONFIG_HX711_PIN_PDSCK=26 ; clock pin
    -D CONFIG_HX711_PIN_PDOUT=25 ; out pin
    -D CONFIG_HX711_SCALE=491    ; scale factor
    -D CONFIG_HX711_TARETIME=20  ; samples we use for tare       
    -D CONFIG_HX711_SAMPLES=10   ; samples we use for avarge value
    -D CONFIG_HX711_WAIT_TIME=2  ; time to wait when toggle pins
    -D CONFIG_HX711_GAIN=1       ; Gain channel A 128=1, 32=3, channel B 64=2 

    [env:...]
    ....

    build_flags = 
        ${hx711.build_flags}

Usage

Add notes about how to use the system.

#include <hx711.h>

After the we declare it

HX711 load();

Then we can tare the weight scale

load.tare()

Then we can start the background task and read the value

load.startTask();
for(;;) 
{
    ESP_LOGI("MAIN", "Weight : %.2f g", load.getLoad());
    vTaskDelay(2000/portTICK_PERIOD_MS);
}

You can find an example in the example folder

Documentation

For more information you can have a look at the documentation.

Todo

• add function to set scale factor