Sample code for BLE ADC Continuous Data Send

int sent_flag=0;
void ub0_interrupt()
{
sent_flag=1;
}
void setup()
{
Serial2.begin(115200);
pinMode(PIN_ESP_IO0, OUTPUT);
pinMode(PIN_ESP_EN, OUTPUT);
digitalWrite(PIN_ESP_IO0, HIGH);
digitalWrite(PIN_ESP_EN, LOW);
delay(10);
digitalWrite(PIN_ESP_EN, HIGH);
pinMode(PIN_SW0, INPUT);
attachInterrupt(4, ub0_interrupt, FALLING);
delay(6000);
Serial.begin(9600);
while(Serial.available()>0)
{
Serial.write(Serial2.read());
}
setup_ble();
Serial.println("bluetooth initialised");
delay(1000);
}
void loop()
{
int analog_value=0;
while(1)
{
analog_value=analogRead(A0);
delay(1000);
if(sent_flag)
{
sent_value(analog_value);
}
}
}

void sent_value(int value)
{
int l=len(value);
Serial2.print("AT+BLEGATTSNTFY=0,1,6,");Serial2.print(l);
send_with_response("",">",500);
Serial2.println(value);

}
int len(int value)
{
if(value!=0)
{
int nDigits=floor(log10(abs(value)))+1;
return nDigits;
}
return 0;
}

void setup_ble()
{

if(send_with_response("AT+BLEINIT=2","OK",1000))
{
Serial.println("bleinit");
}
if(send_with_response("AT+BLEGATTSSRVCRE","OK",1000))
{
Serial.println("gattcre");
}
if(send_with_response("AT+BLEGATTSSRVSTART","OK",1000))
{
Serial.println("gattstart");
}
if(send_with_response("AT+BLEADVSTART","OK",1000))
{
Serial.println("advstart");
}
}

int send_with_response(char* data_to_send,char* expected_data,int wait_time)
{
char recieved_data[200];
long cur,prev;
int x=0;
Serial2.println(data_to_send);
cur=millis();
prev=millis();
while((cur-prev)<wait_time)
{
cur=millis();
if(Serial2.available()>0)
{
recieved_data[x]=Serial2.read();
Serial.print(recieved_data[x]);
x++;
}
}
recieved_data[x]='\0';
Serial.print(recieved_data);
if(strstr(recieved_data,expected_data)!=NULL)
{
return 1;
}
return 0;
}