tello client in ren-c

tello-client.reb

Rebol [
	date: 28-April-2018
	title: "simple tello client"
    author: "Graham"
]

attempt [close tello]

okbin: to binary! {OK}
commands: copy [2 "speed?" 2 "takeoff" 10 "land" 1 "quit"]

tello: open [
    scheme: 'udp
    host: 192.168.10.1
    port-id: 8889
    local-id: 9000

    awake: function [evt] [
        dump evt/type
        port: evt/port
        switch evt/type [
            wrote [
                print "wrote to tello, now reading response"
                read tello
            ]
            read [
                print "looking at port data"
                data: copy port/data
                clear port/data
                dump data
                attempt [print to string! data]
                either not empty? commands [
                    c: take commands
                    if integer? c [
                        print spaced ["sleeping" c "seconds"]
                        sleep c c: take commands
                    ]
                    if c = "quit" [
                        print "Has Quit command so quitting."
                        close port 
                        return true
                    ]
                    write port to binary! c
                ][
                    close port
                    return true
                ]
            ]
            error [
                close port
                return true
            ]
        ]
        false
    ]
]

open tello
read tello

print "send command"
write tello to binary! "command"
wait tello