Hi Paul,
Yes it is communicating over WiFi using TCP.
Here's the receiving (motors) and below this is the sending (client):
#include <ESP8266WiFi.h>
char ssid[] = "Linksys59517"; // SSID of home WiFi
WiFiServer server(80);
WiFiClient client = server.available();
IPAddress ip(192,168,1,213); // name the IP address of the ESP
IPAddress gateway(192,168,1,1); // gateway of your network netstat -nr | grep default
IPAddress subnet(255,255,255,0); // subnet mask of your network
float batteryV;
int highBandLimit = 2500;
int lowBandLimit = 1400;
int slowStartLimit = 3600;
int slowStopLimit = 500;
int upDownInt;
int upDownInt2;
int val3Int;
int val4Int;
int motorValue;
int pwmVal0;
int pwmVal2;
String start;
String upDown;
String upDowna;
String upDownb;
String upDownc;
String upDownd;
String upDown2;
String upDown2a;
String upDown2b;
String upDown2c;
String upDown2d;
String val3;
String val3a;
String val3b;
String val3c;
String val3d;
String val4;
String val4a;
String val4b;
String val4c;
String val4d;
void setup() {
//Serial.begin(115200); // only for debug
WiFi.config(ip, gateway, subnet); // forces fixed IP
WiFi.begin(ssid, pass); // connects to the WiFi router
while (WiFi.status() != WL_CONNECTED) {
Serial.println(".");
delay(50);
}
Serial.println("Connected to wifi");
server.begin();
pinMode(0, OUTPUT);
pinMode(2, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(12, OUTPUT);
pinMode(13, OUTPUT);
pinMode(14, OUTPUT);
pinMode(16, OUTPUT);
digitalWrite(4, LOW);
digitalWrite(5, LOW);
digitalWrite(12, LOW);
digitalWrite(13, LOW);
digitalWrite(14, LOW);
digitalWrite(16, LOW);
}
void loop () {
WiFiClient client = server.available();
Serial.println("Not connected");
//batteryV = analogRead(A0);
if (client) {
server.begin();
while (client.connected()){
if (!client.connected()) {
digitalWrite(2, HIGH);
delay(100);
digitalWrite(2, LOW);
delay(100);
Serial.println();
Serial.println("disconnecting.");
client.stop();
server.available();
}
if(client.available()){
String request = client.readStringUntil('y');
upDowna = request.charAt(0); //upDown
upDownb = request.charAt(1);
upDownc = request.charAt(2);
upDownd = request.charAt(3);
upDown = upDowna + upDownb + upDownc + upDownd;
upDown2a = request.charAt(4); //upDown2
upDown2b = request.charAt(5);
upDown2c = request.charAt(6);
upDown2d = request.charAt(7);
upDown2 = upDown2a + upDown2b + upDown2c + upDown2d;
val3a = request.charAt(8); //val3
val3b = request.charAt(9);
val3c = request.charAt(10);
val3d = request.charAt(11);
val3 = val3a + val3b + val3c + val3d;
val4a = request.charAt(12); //val4
val4b = request.charAt(13);
val4c = request.charAt(14);
val4d = request.charAt(15);
val4 = val4a + val4b + val4c + val4d;
upDownInt = upDown.toInt();
upDownInt2 = upDown2.toInt();
val3Int = val3.toInt();
val4Int = val4.toInt();
Serial.println("upDown is: " + upDown);
Serial.println("upDown2 is: " + upDown2);
Serial.println("val3 is: " + val3);
Serial.println("val4 is: "+ val4);
if (val3Int > highBandLimit && val4Int < highBandLimit
&& val4Int > lowBandLimit){ // move forward, both motors CCW
digitalWrite(5, LOW);
digitalWrite(4, HIGH);
digitalWrite(12, LOW);
digitalWrite(13, HIGH);
if(val3Int > highBandLimit && val3Int < slowStartLimit) {
for(int motorValue = highBandLimit ; motorValue <= slowStartLimit; motorValue += 10){
//motorValue = min(motorValue, 3000);
analogWrite(0, motorValue);
analogWrite(2, motorValue);
delay(1);
}
}
}
else if (val3Int < lowBandLimit && val4Int < highBandLimit
&& val4Int > lowBandLimit){ // move backward, both motors CW
digitalWrite(5, HIGH);
digitalWrite(4, LOW);
digitalWrite(13, LOW);
digitalWrite(12, HIGH);
if(val3Int > slowStopLimit && val3Int < lowBandLimit) {
for(motorValue = lowBandLimit; motorValue >= 10; motorValue -= 10){
//min(motorValue, 3000);
analogWrite(0, (4095-motorValue));
analogWrite(2, (4095-motorValue));
delay(1);
}
}
}
else if (val4Int < lowBandLimit && val3Int < highBandLimit
&& val3Int > lowBandLimit){ // move right, val4 only
digitalWrite(12, HIGH);
digitalWrite(13, LOW);
digitalWrite(4, LOW);
digitalWrite(5, LOW);
Serial.println("right");
analogWrite(0, (4095-motorValue));
}
else if (val4Int > highBandLimit && val3Int < highBandLimit
&& val3Int > lowBandLimit){ // move LEFT, val3 only
digitalWrite(12, LOW);
digitalWrite(13, LOW);
digitalWrite(4, HIGH);
digitalWrite(5, LOW);
Serial.println("left");
analogWrite(0, (4095-motorValue));
}
else if (upDownInt < 2000){ // go down
digitalWrite(16, HIGH);
digitalWrite(14, LOW);
Serial.println("down");
}
else if (upDownInt2 < 2000){ // go up
digitalWrite(14, HIGH);
digitalWrite(16, LOW);
Serial.println("up");
}
else if (upDownInt >= 2000 && val3Int > lowBandLimit && val3Int < highBandLimit
&& val4Int > lowBandLimit && val4Int < highBandLimit){
digitalWrite(4, LOW);
digitalWrite(5, LOW);
digitalWrite(12, LOW);
digitalWrite(13, LOW);
digitalWrite(14, LOW);
digitalWrite(16, LOW);
Serial.print("ALL OFF ");
}
}
}
}
}
I see the word "interrupt" in a topic and odds on it is going to be entirely inappropriate. 
