User manual

LED on and off accordingly. Feedback to the transmitter is transmitted as well. If
another command is sent, the serial monitor reports "Wrong UDP Command". The
same message is also submitted to the transmitter via the network. In the source
code, we will first look at a line in the function configUDP() again:
success &= sendCom("AT+CIPSTART=\"UDP\",\"192.168.4,255
\",90,91", "OK");
The IP has changed now. This IP should look strange to you, since it is not the IP
of your computer. How can the data arrive at all? This IP works because it is a
special IP. This is called a broadcast-IP. The word broadcast is also used, e.g., for
radio channels. Just like radio channels, these broadcast data can be received by
all participants who are in the same subnet. Address 255 at the end of the IP al-
ways means a broadcast address. Now you can start the program Packet Sender,
e.g., on another computer, and listen to all sent messages and also send com-
mands. Communication is no longer limited to two participants.
001
void loop() {
002
if (esp8266.available())
003
{
004
if (esp8266.find("+IPD,"))
005
{
006
if (esp8266.find("led")) {
007
int setLed = esp8266.parseInt();
008
digitalWrite(LED, setLed);
009
010
debug("LED=" + String(setLed));
011
if (sendCom("AT+CIPSEND=7", ">"))
012
{
013
sendCom("LED=" + String(setLed), "OK");
014
}
015
}
016
017
else {