I've been trying to mount a custom protocol over the TCP module on the NodeMCU platform. However, the protocol I try to embed inside the TCP data segment is binary, not ASCII-based(like HTTP for example), so sometimes it contains a NULL char (byte 0x00) ending the C string inside the TCP module implementation, causing that part of the message inside the packet get lost.
-- server listens on 80, if data received, print data to console and send "hello world" back to caller
-- 30s time out for a inactive client
sv = net.createServer(net.TCP, 30)
function receiver(sck, data)
print(data)
sck:close()
end
if sv then
sv:listen(80, function(conn)
conn:on("receive", receiver)
conn:send("hello world")
end)
end
*This is a simple example which, as you can see, the 'receiver' variable is a callback function which prints the data from the TCP segment retrieved by the listener.
How can this be fixed? is there a way to circumvent this using the NodeMCU library? Or do I have to implement another TCP module or modify the current one's implementation to support arrays or tables as a return value instead of using strings?
Any suggestion is appreciated.