Send and receive UDP packet

Troubleshooting
1

Hello,

I am trying to send a character from a photon to another photon using UPD. The sending photon uses this code:

UDP Udp;
char buffer1[] = "a";
IPAddress remoteIP(192, 168, 1, 104);
int port = 8888;
void setup() {
   Udp.begin(8888);
   Serial.begin(9600);
}
void loop(){ 
 if (Udp.sendPacket(buffer1, sizeof(buffer1), remoteIP, port) < 0) {
    Serial.println("Error");
}

The receiving photon runs this code:

unsigned int port = 8888;
UDP Udp;
void setup() {
    Serial.begin(9600);
    Udp.begin(port);
}
void loop(){
    if (Udp.parsePacket() > 0)    {
        Serial.println("character received");
        int i = Udp.read();
        Serial.println(i);
        Udp.flush();
    }
}

I don’t get an error but the receiving photon doens’t seem to receive anything. I am sure that I using the correct IP-address. What could be wrong? I assume UPP is supported with the particle photon (photons were bought one month ago).

Thanks in advance,
Bart

2

Have you double checked your receivers IP? e.g. via WiFi.localIP()

3

Yep, even triple checked. I assume the photon supports UDP

4

It does - if it wasn’t it would not be in the docs :wink:
Does your router allow UDP?
Can you use UDP with your computer on that network?

5

That was the problem. It works now!

Thanks for your advice!

6

I got UDP working from Photon to Photon(s) (to a broadcast IP) and can offer my hard-won lessons if you are still struggling with this - where I ended up looks very similar to your code, though, so you’re definitely on the right track.

However, I have my own problem where it works great for a while, and then devices just stop picking up the broadcast packets. I am going to start my own thread on that.

Anyway, post again to let us know how it turned out!

7

Hello Patrick,

The problem was that my access point wasn’t enabled for UDP-packets. Now it is and it seems to work.

Thanks for the reply,
Bart

1 Like