Question

Can you write an arduino code to learn Hx711 and two Strain gauge value with Half wheatstone bridge?

Answer 1

To write strain gauge in an arduino code which is given below as :

#include <TFT.h>  // Arduino LCD library
#include <SPI.h>

// pin definition for the MICRO
#define cs   7 
#define dc   0
#define rst  1 

TFT TFTscreen = TFT(cs, dc, rst);

// char array to print to the screen
char strainPrint[4];
char thermoPrint[4];

void setup() {

  // Put this line at the beginning of every sketch that uses the GLCD:
  TFTscreen.begin();

  // clear the screen with a white background
  TFTscreen.background(255, 255, 255);

  // write the static text to the screen
  // set the header font color to black
  TFTscreen.stroke(0, 0, 0);
  // set the font size
  TFTscreen.setTextSize(2);
  // write the text to the top left corner of the screen
  TFTscreen.text("Sensor Values :\n ", 0, 0);
  // ste the font size very large for the loop
  TFTscreen.setTextSize(4);
}

void loop() {

  // Read the value of the strain sensor on A0
  String strainVal = String(analogRead(A0));
  // Read the value of the thermo sensor on A1
  String thermoVal = String(analogRead(A1));

  // convert the readings to char arrays
  strainVal.toCharArray(strainPrint, 4);
  thermoVal.toCharArray(thermoPrint, 4);

  // set the font color for strain output to blue
  TFTscreen.stroke(255, 0, 0);
  // print the strain sensor value
  TFTscreen.text(strainPrint, 0, 20);
  // set the font color for thermo output to red
  TFTscreen.stroke(0, 0, 255);
  // print the thermo sensor value
  TFTscreen.text(thermoPrint, 0, 60);
  // wait for a moment
  delay(250);
  // clear screen
  TFTscreen.stroke(255, 255, 255);
  TFTscreen.text(strainPrint, 0, 20);
  TFTscreen.text(thermoPrint, 0, 60);
}

The Hx711 uses SPI interface to communiacate to the Arduino. Scale manufacturers use specifically designed ICs to convert the analog voltage reading to digital, the HX711 is one such specialized instrument amplifier that is commonly used inside many consumer scales. The HX711 is powered from 2.7 to 5V and uses a 2 wire digital interface (Clock and Data).