Capacitive Soil Moisture Sensor

I am trying to use a capacitive soil moisture sensor with a nodemcu but I'm only getting 2 values, 1023 when dry or 0 when wet. How do I get this to read in the middle?

Sensor: https://www.diymore.cc/products/2pcs-capacitive-soil-moisture-sensor-v1-2-analog-corrosion-resistant-dc-3-3-5-5v

Sketch:

void setup() {
  Serial.begin(115200);
}
void loop() {
  int val;
  val = analogRead(D1);
  Serial.println(val);
  delay(500);
}

I have Vcc to Vcc. Gnd to Gnd. Analog out to D0,

You can only use amalogRead() on the analog pin of your board.

pert:
You can only use amalogRead() on the analog pin of your board.

I can’t believe I did that.

So now I get actual analog data however I am having trouble getting it to my mqtt server

/*
 Basic ESP8266 MQTT publish client example for a moisture sensor
*/
#include <ESP8266WiFi.h>
#include <PubSubClient.h>

// Update these with values suitable for your network.
const char* ssid = "REMOVED";
const char* password = "REMOVED";
const char* mqtt_server = "REMOVED";

WiFiClient espClient;
PubSubClient client(espClient);

void setup_wifi() {
  // Connecting to a WiFi network
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  // Loop until we're reconnected
  Serial.println("In reconnect...");
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect("Arduino_Moisture")) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
}

void loop() {
  char msg[10];
    
  if (!client.connected()) {
    reconnect();
  }

  float maxv=1023;
  
  int val=analogRead(A0);  
  Serial.print("analog value: ");
  Serial.println(val);
  
  float SoilMoisture=val/maxv*100;
  Serial.print("Percentage: ");
  Serial.println(SoilMoisture);
  
  sprintf(msg,"%i",SoilMoisture);  //if I replace "SoilMoisture" with "val" I get actual readings
  client.publish("Sensor", msg);
  delay(500);
}

Through serial I am getting good results:

analog value: 818
Percentage: 79.96
analog value: 821
Percentage: 80.25

However when it is sent though mqtt i am getting out a random gargle of numbers:

1610612736
-2147483648
1073741824
1610612736
-536870912
0
0
1610612736
536870912
-2147483648

If I replace “SoilMoisture” with “val”, the mqtt messages are actual readings just not in the format that I need:

814
814
814
816
816
816

sprintf's %i specifier is for use with a signed integer type, but you're passing it a float. Try casting SoilMoisture to the int type:

sprintf(msg,"%i",(int)SoilMoisture);

Any one knows where to find the graph : moist level (%) to output voltage (V or mV) for this sensor ?

tanx in advance ! :)

The moist level (%) to output voltage (V or mV) will be different from one sensor model/manufacturer to another. This kind of information is available in the manufacturer datasheet of that particular sensor that you have. You can find the datasheet by doing a google search or, most of the time, directly on the distributor website where you got that sensor.