How to send broadcast message to all iOT device in android?

Question

I have some iOT devices , currently i am creating tcp socket connection one by one to all of the device, all devices are connected to my local wifi.

Is it possible to send one command to all devices at a time, like a broadcast pattern? Is it possible to send and receive broadcast message in android?

Answer 1

Yes you can send broadcast message to all your device connected on to your network. But for that you need to understand broadcast IP address of your subnet / net. Which is something like 255.255.255.255.So get your subnet mask first and your ip address. Once you have both find your NETWORK Address. Do a search how to calculate network address from IP address and Mask. Once you have Network address do a search about how to get broadcast address. Now when you have broadcast address you need to create DATAGRAM socket (UDP) with the broadcast address. All your IOT devices must be listening on that UDP socket. So once you send your data to this UDP socket all your devices on the network will receive that message.

Check here for java based implementation Check here for how to get broadcast address from ip and subnet mask