We are looking to use one of the single relay wifi connection boards for an access control system. Have a couple of questions:
Our wifi can not have static IP’s. Can the startup process of the board, once it has connected to a wifi network with dhcp, be to make a rest call to our server with its mac address and its new IP? This way as it connects at different points and has different IP’s we could dynamically update those on our server for when we do a rest call to turn the relay on/off? Also if for whatever reason its IP is changed via dhcp, it could do the same call?
If using http get to turn the relay on/off, can you get feedback either from the get or from the relay itself to know if the command was received and implemented?
How is the board itself secured on the wifi network so that only our server on the network can command it to open/close the relay?
When the relay controller boots up it will send out a UDP broadcast on interval using port 13000 and 55555 that contains its connection information. It will broadcast this message across the network. If the server you want to connect from is on a different network then you would have to configure the router to forward the broadcast.
A simpler solution is to configure the WiFi module to connect to your server using TCP/IP. This will tell the wifi module to attempt to open a socket to your server on boot and you can communicate this way.
When the relay controller receives a relay control command it will respond with an 85. It will respond with this over HTTP, TCP, or Web Socket.
There is not a way to secure the wifi module on the network. If a TCP socket is open to the board nothing else can connect to that TCP socket, but the Web Socket API will still function if another device attempts to control it.