ESP8266 Developer Zone

Re: Can UDP socket support multicast using AT commands?

2017-06-06T04:00:16+08:00

The problem I see is that if you do not know the netmask then you cannot know the broadcast address.
(The examples above only work when the netask is 0xFFFFFF00.)
I do not see any way to get the netmask with the AT commands. Is there a way?

Statistics: Posted by RogerFL — Tue Jun 06, 2017 4:00 am

Re: Can UDP socket support multicast using AT commands?

2016-11-09T17:13:12+08:00

Hi,

I need to receive broadcast UDP datagrams with AT commands but it does not work.
Using the following command

AT+CIPSTART=4,"UDP","0",0,1300,2

the 8266 only receive datagrams directed to its own IP and does not receive broadcasts.

Someone can help?

Statistics: Posted by lucio.macellari.mac — Wed Nov 09, 2016 5:13 pm

Re: Can UDP socket support multicast using AT commands?

2016-08-08T13:48:54+08:00

Hi akouz,

Thanks for your information. It basically works.
A minor feedback of this "AT+CIPSTART=4,"UDP","192.168.1.255",1300,1300,2 - command to module: open connection 4, UDP, broadcast address, port 1300, time-out 2 sec", 2 is not time-out for UDP, but it is for TCP. For UPD transmission, it is UDP mode.

One more question, for UDP broadcasting, how should we know where is the message received from? To implement recvfrom function, we need to know the client's IP address and port number. Can you suggest which API in the SDK can be used? Thanks.

Statistics: Posted by ftdiyun — Mon Aug 08, 2016 1:48 pm

Re: Can UDP socket support multicast using AT commands?

2016-07-22T11:38:14+08:00

AT+CIPSTART=4,"UDP","192.168.1.255",1300,1300,2 - command to module: open connection 4, UDP, broadcast address, port 1300, time-out 2 sec
4,CONNECT
OK - module replies
AT+CIPSEND=4,16 - command to module: connection 4, 16 bytes to send
OK
> - module is ready to read data
send 16 bytes of data
Recv 16 bytes
SEND OK - module replies
AT+CIPCLOSE=4 - command to module: close connection 4
4,CLOSED
OK - module replies

Statistics: Posted by akouz — Fri Jul 22, 2016 11:38 am

Re: Can UDP socket support multicast using AT commands?

2016-07-22T11:23:24+08:00

Hi Pratik,
Thanks for your reply. Can you share an example using the AT commands for UDP multicast? Thanks.

Statistics: Posted by ftdiyun — Fri Jul 22, 2016 11:23 am

Re: Can UDP socket support multicast using AT commands?

2016-07-21T12:19:04+08:00

Yes, it does.
If you have many devices listening to the same post, you can send a packet to the UDP broadcast address (instead of a particular device), which will be broadcast to all the other devices that are listening.
The broadcast address is the last host address within the range defined by the subnet mask.

Statistics: Posted by Guest — Thu Jul 21, 2016 12:19 pm

Can UDP socket support multicast using AT commands?

2016-07-20T14:35:31+08:00

Thanks

Statistics: Posted by ftdiyun — Wed Jul 20, 2016 2:35 pm