Problem at displaying sensor value in 2.8" TFT touchscreen mcufriend 0x4747

Other Hardware Displays
8

The Library Manager could not find an "official" HX711 library. So I was not able to reproduce your program exactly.

However, this example illustrates two ways of printing a varying number. I use a YELLOW background to highlight the printed characters.

#include <MCUFRIEND_kbv.h>
MCUFRIEND_kbv tft;

#define BLACK   0x0000
#define BLUE    0x001F
#define RED     0xF800
#define GREEN   0x07E0
#define CYAN    0x07FF
#define MAGENTA 0xF81F
#define YELLOW  0xFFE0
#define WHITE   0xFFFF

void setup()
{
    Serial.begin(9600);
    uint16_t identifier = tft.readID();
    tft.begin(identifier);
    Serial.print(identifier);
    tft.setRotation(1);
    tft.fillScreen(WHITE);
    tft.setTextSize(4);
    tft.setTextColor(BLACK, YELLOW);  //set back colour for rubout
}

void loop()
{
    float result = 0.01 * random(-10000, 30000); //-100.0 to +300.00
    Serial.println(result, 2);
    tft.setCursor(130, 100);
    tft.print(result, 2);            //2 decimals
    tft.print(" ");                  //rubs out old digit

    tft.setCursor(130, 140);
    char buf[10];
    dtostrf(result, 6, 2, buf);   //width=6, prec=2
    tft.print(buf);               //-99.99 to 299.99
    delay(1000);                  //wait between readings
}

Note that the "trailing space" method works with similar numbers but goes wrong when the result width varies.
Using dtostrf() gives you nice formatted output. You can even use it for integers if you use prec=0.

David.