What you're wanting to do is dereference the pointer - but before we get to that there is a problem
node is a pointer to a char array, and while you 'could' dereference it fine (assuming you want to get the first value in the array) it's not a good practice to do so.
What you will want to do is use an index to get the byte vale you are wanting.
Can you give an example of what you are expecting val to be when you send it? It looks as if you are really trying to send a string as a byte, which won't work. (for example, sending I looks to be trying to fit "KEY_I" into a byte)