HX711 bodge library with display shield 1602 - issues reading a0

Hi all, I am relatively new to arduino programing and have a following issue:

I have an arduino uno with a display shield 1602 connected to it. Additionally I have an HX711 A/D connected over display shield in a way that A1 is connected to CK/TX and A3 is connected to DO/RX. If I try to read the A0 (meaning the keys on display shield) with analogRead(A0) everything reads ok until I try to initialize the HX711 library (with HX711 scale(A3, A1); line ) once this is added to my code the analogRead(A0) always returns number 7.

The example code that can be used to replicate is like

#include <HX711.h>
#include <LiquidCrystal.h>

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
HX711 scale(A3, A1);	

void setup() {
  // set up the LCD's number of columns and rows:

  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("LCD Key Shield");
  lcd.print("Press Key:");

void loop() {
  int x;
  x = analogRead (0);
  if (x < 60) {
    lcd.print ("Right ");
  else if (x < 200) {
    lcd.print ("Up    ");
  else if (x < 400){
    lcd.print ("Down  ");
  else if (x < 600){
    lcd.print ("Left  ");
  else if (x < 800){
    lcd.print ("Select");

If the line with HX711 scale(A3, A1); is removed then the keys are read correctly. But once I add that line I always get 'Press Key: Right' (since analogRead(A0) is always 7).

Could anyone point me to what I am doing wrong? Is there any restriction for usage of analog pins over display shield?

Thanks for any help,


Try swapping A0..A3.