ADC for pressure sensor

Hello everybody,
hope you can help me with my problem . I’m using an Arduino 1 to read a pressure sensore but I use the an ADC 16 bit too to make it readable . I’ve included the proper library for my ADC (adafruit) and I’ve connected the circuit as shown on the website
link : Convertitore a ADC 16Bit ADS1115 su Arduino- pagina 1 - Arduino
and I wrote this code :

#include “Wire.h”
#include<Adafruit_ADS1015.h>
Adafruit_ADS1115 ads;

void setup() {
// put your setup code here, to run once:

Serial.begin(9600);
ads.begin();

}

void loop() {
int16_t adc0;// int16 per indicare la lettura di una variabile a 16 bit

adc0 = ads.readADC_SingleEnded(0); //è il pin A0 del Adc
Serial.print("CHANNEL 0: "); Serial.println(adc0);

}

it does not work totally, the only output printed is -1 … -1 … can you tell me why?

if the question looks pathetic I apologize , I’m new …

thank you everyone will spend a second to read my post and maybe suggest me something

regards

Saffo:
I'm using an Arduino 1 to read a pressure sensore...

Which one.
Post a link to the sensor.

Saffo:
but I use the an ADC 16 bit too to make it readable.

Only sensors with a voltage or current output can be used with an ADS1115.
Ratiometric sensors will give instability and zeroing problems.
Leo..

Why?
Maybe your wires are not connected properly.
Maybe you forgot to solder all connections properly.
Maybe you connected it to a different input than 0.
Maybe your chip is set to a different I2C address.
What is the voltage you measure at the pin of the ADC chip itself?

-1 indicates a total communication failure: do you see the chip's I2C address when running an I2C scanner? Does it match the address where the library expects to find it? (if not, tell the library the correct address - see documentation).