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Serial Port Reader

Code to drive a serial port. Trivial application to read a paper tape to a file from a GNT4604 paper tape reader attached to serial port COM3:

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#light

// Program to read a paper tape to a file from a GNT4604 paper tape reader
// attached to serial port COM3:

module ReadTape
    
    open System.IO

    exception NoTape  // used to force exit when no further tape to read

    // Open serial port 
    let OpenPort () =
        let port = new System.IO.Ports.SerialPort ("COM3", 4800, Ports.Parity.None, 8, Ports.StopBits.One)
        port.Open ()
        port.DtrEnable   <- true
        port.RtsEnable   <- true
        port.ReadTimeout <- 1000
        port 

    let port = OpenPort ()                   

    let ReadRaw f =
        let buffer: byte[] = Array.zeroCreate (250*60*30) // 15 minutes of paper tape reading 
        let rec GetBytes i = 
            try 
                    buffer.[i] <- byte (port.ReadByte ()) 
                    GetBytes (i+1)
            with 
            _   ->  i // finish on timeout    
        printfn "Reading tape to %s" f
        printf "Load tape and type hit any key..."
        System.Console.ReadLine () |> ignore
        let count = (GetBytes 30)+30 // force 3 inches of leader and trailer)
        printfn "%d bytes input" (count-60)
        let rec TrimLeft i =
            if   i = count
            then printfn "Empty tape"
                 0
            elif buffer.[i] = 0uy 
            then TrimLeft (i+1) 
            else i
        let rec TrimRight i =
            if   i = 0
            then printfn "Empty Tape"
                 count
            elif buffer.[i] = 0uy 
            then TrimRight (i-1) 
            else i
        let start  = max 30 ((TrimLeft 0)-30)
        let finish = min (count-30) ((TrimRight count)+30)       
        let trimmed = buffer.[start..finish]
        printfn "%d bytes output" trimmed.Length
        try File.WriteAllBytes (f, trimmed) with
        e   -> System.Console.WriteLine f


    let  cmdLine = System.Environment.GetCommandLineArgs()
    if   cmdLine.Length < 2
    then System.Console.WriteLine "Error: READTAPE file"
    else ReadRaw cmdLine.[1]

module ReadTape

namespace System

namespace System.IO

exception NoTape

Full name: ReadTape.NoTape

val OpenPort : unit -> Ports.SerialPort

Full name: ReadTape.OpenPort

val port : Ports.SerialPort

namespace System.IO.Ports

Multiple items
type SerialPort =
  inherit Component
  new : unit -> SerialPort + 6 overloads
  member BaseStream : Stream
  member BaudRate : int with get, set
  member BreakState : bool with get, set
  member BytesToRead : int
  member BytesToWrite : int
  member CDHolding : bool
  member Close : unit -> unit
  member CtsHolding : bool
  member DataBits : int with get, set
  ...

Full name: System.IO.Ports.SerialPort

--------------------
Ports.SerialPort() : unit
Ports.SerialPort(container: System.ComponentModel.IContainer) : unit
Ports.SerialPort(portName: string) : unit
Ports.SerialPort(portName: string, baudRate: int) : unit
Ports.SerialPort(portName: string, baudRate: int, parity: Ports.Parity) : unit
Ports.SerialPort(portName: string, baudRate: int, parity: Ports.Parity, dataBits: int) : unit
Ports.SerialPort(portName: string, baudRate: int, parity: Ports.Parity, dataBits: int, stopBits: Ports.StopBits) : unit

field Ports.Parity.None = 0

type StopBits =
  | None = 0
  | One = 1
  | Two = 2
  | OnePointFive = 3

Full name: System.IO.Ports.StopBits

field Ports.StopBits.One = 1

Ports.SerialPort.Open() : unit

property Ports.SerialPort.DtrEnable: bool

property Ports.SerialPort.RtsEnable: bool

property Ports.SerialPort.ReadTimeout: int

val port : Ports.SerialPort

Full name: ReadTape.port

val ReadRaw : f:string -> unit

Full name: ReadTape.ReadRaw

val f : string

val buffer : byte []

Multiple items
val byte : value:'T -> byte (requires member op_Explicit)

Full name: Microsoft.FSharp.Core.Operators.byte

--------------------
type byte = System.Byte

Full name: Microsoft.FSharp.Core.byte

module Array

from Microsoft.FSharp.Collections

val zeroCreate : count:int -> 'T []

Full name: Microsoft.FSharp.Collections.Array.zeroCreate

val GetBytes : (int -> int)

val i : int

Ports.SerialPort.ReadByte() : int

val printfn : format:Printf.TextWriterFormat<'T> -> 'T

Full name: Microsoft.FSharp.Core.ExtraTopLevelOperators.printfn

val printf : format:Printf.TextWriterFormat<'T> -> 'T

Full name: Microsoft.FSharp.Core.ExtraTopLevelOperators.printf

type Console =
  static member BackgroundColor : ConsoleColor with get, set
  static member Beep : unit -> unit + 1 overload
  static member BufferHeight : int with get, set
  static member BufferWidth : int with get, set
  static member CapsLock : bool
  static member Clear : unit -> unit
  static member CursorLeft : int with get, set
  static member CursorSize : int with get, set
  static member CursorTop : int with get, set
  static member CursorVisible : bool with get, set
  ...

Full name: System.Console

System.Console.ReadLine() : string

val ignore : value:'T -> unit

Full name: Microsoft.FSharp.Core.Operators.ignore

val count : int

val TrimLeft : (int -> int)

val TrimRight : (int -> int)

val start : int

val max : e1:'T -> e2:'T -> 'T (requires comparison)

Full name: Microsoft.FSharp.Core.Operators.max

val finish : int

val min : e1:'T -> e2:'T -> 'T (requires comparison)

Full name: Microsoft.FSharp.Core.Operators.min

val trimmed : byte []

property System.Array.Length: int

type File =
  static member AppendAllLines : path:string * contents:IEnumerable<string> -> unit + 1 overload
  static member AppendAllText : path:string * contents:string -> unit + 1 overload
  static member AppendText : path:string -> StreamWriter
  static member Copy : sourceFileName:string * destFileName:string -> unit + 1 overload
  static member Create : path:string -> FileStream + 3 overloads
  static member CreateText : path:string -> StreamWriter
  static member Decrypt : path:string -> unit
  static member Delete : path:string -> unit
  static member Encrypt : path:string -> unit
  static member Exists : path:string -> bool
  ...

Full name: System.IO.File

File.WriteAllBytes(path: string, bytes: byte []) : unit

val e : exn

System.Console.WriteLine() : unit
   (+0 other overloads)
System.Console.WriteLine(value: string) : unit
   (+0 other overloads)
System.Console.WriteLine(value: obj) : unit
   (+0 other overloads)
System.Console.WriteLine(value: uint64) : unit
   (+0 other overloads)
System.Console.WriteLine(value: int64) : unit
   (+0 other overloads)
System.Console.WriteLine(value: uint32) : unit
   (+0 other overloads)
System.Console.WriteLine(value: int) : unit
   (+0 other overloads)
System.Console.WriteLine(value: float32) : unit
   (+0 other overloads)
System.Console.WriteLine(value: float) : unit
   (+0 other overloads)
System.Console.WriteLine(value: decimal) : unit
   (+0 other overloads)

val cmdLine : string []

Full name: ReadTape.cmdLine

type Environment =
  static member CommandLine : string
  static member CurrentDirectory : string with get, set
  static member Exit : exitCode:int -> unit
  static member ExitCode : int with get, set
  static member ExpandEnvironmentVariables : name:string -> string
  static member FailFast : message:string -> unit + 1 overload
  static member GetCommandLineArgs : unit -> string[]
  static member GetEnvironmentVariable : variable:string -> string + 1 overload
  static member GetEnvironmentVariables : unit -> IDictionary + 1 overload
  static member GetFolderPath : folder:SpecialFolder -> string + 1 overload
  ...
  nested type SpecialFolder
  nested type SpecialFolderOption

Full name: System.Environment

System.Environment.GetCommandLineArgs() : string []

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More information

Link:	http://fssnip.net/9s
Posted:	12 years ago
Author:	Andrew Herbert
Tags:	ports , serial , paper tape