why i get the same value that i send the last

Projects Programming
1

why i get the same value that i send the last to thingspeak

#include <SoftwareSerial.h>
#include <string.h>
#include <stdlib.h>

#define esp8266 Serial1

#define SSID "test"    // put here the name of your wifi network
#define PASS "lolman123"    
#define IP "184.106.153.149"

int counter = 100;
int resetpoint = 100;
String keep;
String valuetosend;

const int resetPin = 3;
const int resetPoint = 3;

String GET = "GET /update?key=FYPW04TOYR3FX2QH&";    // put here your thingspeak key
String GET1 = "field1=";

const byte numChars = 32;
char receivedChars[numChars];

boolean newData = false;

String readGET1 = "GET https://api.thingspeak.com/channels/864152/fields/1/last";

int ex_int = 10;
int ex_int_keep;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  esp8266.begin(115200);
  Serial.println("Resetting...");
  esp8266.println("AT");
  delay(2000);
  if(esp8266.find("OK")){
    connectWiFi();
    Serial.println("WIFI CONNECTED");
  }
  pinMode(7, INPUT_PULLUP);
  pinMode(8, INPUT_PULLUP);
  pinMode(resetPoint, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  int readBtn = digitalRead(7);
  int readSend = digitalRead(8);
  int readResetPoint = digitalRead(resetPoint);
  
  if (readBtn == 0)
  {
    ReadLastEntryThingSpeak();
  }

  if (readSend == 0)
  {
    WriteThingSpeak();
  }
}

boolean connectWiFi(){
  esp8266.println("AT+CWMODE=3");
  delay(2000);
  String cmd="AT+CWJAP=\"";
  cmd+=SSID;
  cmd+="\",\"";
  cmd+=PASS;
  cmd+="\"";
  esp8266.println(cmd);
  delay(5000);
  if(esp8266.find("OK")){
    Serial.println("OK");
    return true;
  }else{
    Serial.println("KO");
    return false;
  }
}

void updateFunction(String valuetosend){
  String cmd = "AT+CIPSTART=\"TCP\",\"";
  cmd += IP;
  cmd += "\",80";
  esp8266.println(cmd);
  delay(2000);
  if(esp8266.find("Error")){
    Serial.print("Error1");
    return;
  }
  cmd = GET + GET1;
  cmd += valuetosend;
  cmd += "\r\n";
  Serial.print(cmd);
  esp8266.print("AT+CIPSEND=");
  esp8266.println(cmd.length());
  if(esp8266.find(">")){
    esp8266.print(cmd);
  }else{
    esp8266.println("AT+CIPCLOSE");
  }
  delay(2000);
  ResetEverything ();
}

void ReadLastEntryThingSpeak()
{
  String cmd = "AT+CIPSTART=\"TCP\",\"";
  cmd += IP;
  cmd += "\",80";
  esp8266.println(cmd);
  delay(2000);
  if(esp8266.find("Error")){
    Serial.print("Error1");
    return;
  }
  cmd = readGET1;
  cmd += "\r\n";
  Serial.print(cmd);
  esp8266.print("AT+CIPSEND="); 
  esp8266.println(cmd.length());
  if(esp8266.find(">")){
    esp8266.print(cmd);
  }else{
    esp8266.println("AT+CIPCLOSE");
  }
  delay(5000);
  if (esp8266.find("+IPD,"))
  {
    recvWithStartEndMarkers();
    Serial.print("The last value of field 1 is ");
    Serial.println(receivedChars);
    ex_int_keep = (receivedChars[0] - '0') * 100; //Convert char to int
    ex_int_keep += (receivedChars[1] - '0') * 10;
    ex_int_keep += receivedChars[2] - '0';
    Serial.print("The value of ex_int_keep is ");
    Serial.println(ex_int_keep);
  }  
}

void WriteThingSpeak ()
{
    int sum = counter + ex_int_keep;
    String valuetosend = String(sum);
    updateFunction(valuetosend);
}

void ResetEverything ()
{
  esp8266.println("AT+RST");
  delay(2000);
  ex_int_keep = 0;
  Serial.println("Ready to use!");
}

void recvWithStartEndMarkers() {
    static boolean recvInProgress = false;
    static byte ndx = 0;
    char startMarker = ':';
    char endMarker = 'C';
    char rc;
 
    while (esp8266.available() > 0 && newData == false) {
        rc = esp8266.read();

        if (recvInProgress == true) {
            if (rc != endMarker) {
                receivedChars[ndx] = rc;
                ndx++;
                if (ndx >= numChars) {
                    ndx = numChars - 1;
                }
            }
            else {
                receivedChars[ndx] = '\0'; // terminate the string
                recvInProgress = false;
                ndx = 0;
                newData = true;
            }
        }

        else if (rc == startMarker) {
            recvInProgress = true;
        }
    }
}

when i press read button to get the last data to keep in ex_int_keep and then i press send button to modify it by plus with 100 and sent it back to thingspeak
the problem is here. after i press send button, i press read button to get the last data, but i got the same value that i get from the begin

From Serial Monitor

Resetting...
OK
WIFI CONNECTED
GET https://api.thingspeak.com/channels/864152/fields/1/last
The last value of field 1 is 400
The value of ex_int_keep is 400
GET /update?key=FYPW04TOYR3FX2QH&field1=500 //the value that i send
Ready to use!
GET https://api.thingspeak.com/channels/864152/fields/1/last
GET https://api.thingspeak.com/channels/864152/fields/1/last
The last value of field 1 is 400 //the actual result is 500
The value of ex_int_keep is 400 //the actual result is 500

to make the result correct, i must reset arduino. but it has a better way to do that without resetting?

2

Pff that is why i never use the AT commands, i can hardly read what is going on,
first of all, does esp8266.println(cmd.length());terminate with \r\n ? or should it be

esp8266.print(cmd.length());
esp8266.print("\r\n");

?

My suspicion is you have not received newdata, so here:

{
    recvWithStartEndMarkers();

    if (!newData) Serial.println("No new Data Received");

    Serial.print("The last value of field 1 is ");
    Serial.println(receivedChars);
    ex_int_keep = (receivedChars[0] - '0') * 100; //Convert char to int
    ex_int_keep += (receivedChars[1] - '0') * 10;
    ex_int_keep += receivedChars[2] - '0';
    Serial.print("The value of ex_int_keep is ");
    Serial.println(ex_int_keep);
  }

to confirm that.
If that is the case, receive may still be in progress, and the buffer is still holding the data from the first time around. Probably your endmarker never shows up.