transporter.fs

open System
let L  = 14. // Space between wheels || Your values might be quite different
let R  = 2.7 // Wheel's radius       ||
let ticksPerRotation = 12000. // ~ amount of ticks is taken by one full rotation 
let desiredAngle = int ((L/R/4.) * ticksPerRotation) // Math routine to calculate how many ticks is taken to turn

type Direction = Forward | Backward | Left | Right


// <Twitter boilerplate part> 
let direction = new Trik.Notifier<_>()
let dir (key: ConsoleKey) = 
    match key with
    | ConsoleKey.UpArrow -> Forward
    | ConsoleKey.DownArrow -> Backward
    | ConsoleKey.LeftArrow -> Left
    | ConsoleKey.RightArrow -> Right
    | _ -> Forward

let loop() = 
    while true do
        let curr = dir <| Console.ReadKey().Key
        //printfn "%A" curr
        direction.OnNext curr

let twitter = direction.Publish
// </Twitter boilerplate part> 


let model = new Trik.Model()
let encoderL = model.Encoder.["B4"]
let encoderR = model.Encoder.["B1"]
let encoderRead() = (encoderL.Read(), encoderR.Read())
let first = encoderRead()

let setWheels (l,r) = model.Motor.["M4"].SetPower l; model.Motor.["M1"].SetPower r

twitter.Subscribe(fun x -> printfn "%A" x
                           match x with
                           | Forward -> setWheels (100,100)
                           | Backward -> setWheels (-100,-100)
                           | Left -> 
                               setWheels (0,100)
                               encoderR.Reset()
                               let angle = desiredAngle - 65536
                               while -encoderR.Read() < angle do
                                     System.Threading.Thread.Sleep 100
                               setWheels (100,100)
                           | Right -> 
                               setWheels (100,0)
                               encoderL.Reset()
                               while encoderL.Read() < desiredAngle do
                                     System.Threading.Thread.Sleep 100
                               setWheels (100,100)
                  ) |> ignore
printfn "Ready"

loop() //Press arrow keys to manipulate robot