Error in serial communication or uploading of node mcu

[ubaid12ur]

I have a problem.
I connected my NANO with Node MCU 0.9 (esp8266). via rx and tx and gnd.
And I use thingspeak library .
Then I put voltage sensor in node mcu
now ,
temperature1 = field 1.
temperature2 = field 2.
temperature3 = field 3.
voltage = field 4.

here's code for node mcu.

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ThingSpeak.h>

#define ANALOG_IN_PIN A0

const char *ssid = "************";
const char *password = "****************";
const char *thingSpeakApiKey = "47JIN--------IOA";
const unsigned long myChannelNumber = 2535942;

float R1 = 30000.0;
float R2 = 7500.0;
float ref_voltage = 5.0;

WiFiClient client;

void setup() {
  Serial.begin(9600);
  WiFi.begin(ssid, password);

  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" Connected!");

  ThingSpeak.begin(client);
}

void loop() {
  if (WiFi.status() == WL_CONNECTED) {
    float temperature1, temperature2, temperature3, voltage;

  if (Serial.available() >= 16) { 
    temperature1 = Serial.parseFloat();
    temperature2 = Serial.parseFloat();
    temperature3 = Serial.parseFloat();
    

    while (Serial.available() > 0) {
      Serial.read();
    }

    int adc_value = analogRead(ANALOG_IN_PIN);
    float adc_voltage = (adc_value * ref_voltage) / 1024.0;
    float in_voltage = adc_voltage * ((R1 + R2) / R2);

    Serial.print("Input Voltage = ");
    Serial.println(in_voltage, 2);
        Serial.println("Updating ThingSpeak fields");

    ThingSpeak.setField(1, temperature1);
    ThingSpeak.setField(2, temperature2);
    ThingSpeak.setField(3, temperature3);
    ThingSpeak.setField(4, in_voltage);

    int response = ThingSpeak.writeFields(myChannelNumber, thingSpeakApiKey);
    if (response == 200) {
      Serial.println("Data sent to ThingSpeak successfully");
    } else {
      Serial.println("Failed to send data to ThingSpeak");
    }
  } else {
    Serial.println("WiFi not connected, Retrying...");
    WiFi.begin(ssid, password);
  }

  delay(2000); 
}}

The nano tells correct reading

but node mcu on thingspeak have errors

I moved your topic to an appropriate forum category @ubaid12ur.

In the future, please take some time to pick the forum category that best suits the subject of your topic. There is an "About the _____ category" topic at the top of each category that explains its purpose.

This is an important part of responsible forum usage, as explained in the "How to get the best out of this forum" guide. The guide contains a lot of other useful information. Please read it.

Thanks in advance for your cooperation.

[ubaid12ur]

Thanks but I couldn't find my category there so I chose using Arduino

You chose the Uncategorized category, which is clearly marked "DO NOT USE". This shows you did not take the time to read the information about the purpose of the category.

This is the fourth time you have done that. I have politely asked you to select an appropriate category for your topics multiple times already, yet you continue to use the completely inappropriate category.

Since it seems that asking nicely isn't working with you, I'm going to give you a short account suspension in hopes that will convince you to start being more responsible and respectful in how you use our forum.