(+ newLISP Windows RS232)

[Fritz]

I need to communicate with standart rs-232 serial port on PC.



Is it possible to write on newLISP something like (read-port "COM1" 20)?

[itistoday]

Couldn't you use the "import" function to import the necessary C functions from some windows DLL?

[Fritz]

Couldn't you use the "import" function to import the necessary C functions from some windows DLL?

Well, I'll try. I'm not too familiar with C, but it is a good reason to learn it closer.

[Robert Gorenc]

Hi Fritz,

do you have same success in writing to serial port?

I also would like to talk to uC with forth on board via serial port from Linux.

I didn't jet try, maybe this weekend....

[Fritz]

do you have same success in writing to serial port?

Yep. Here is a part of working code (Windows PC):

Code Select Expand

; Initialization
(define (scales-init)
  (exec "mode COM1 BAUD=9600 PARITY=N DATA=8 STOP=1"))

; Getting data from COM-port
(define (scales-weight-up)
  (local (hndl buff)
    (set 'hndl (open "COM1" "r"))
    (read hndl buff 40 (char 0x0D))
    (close hndl)
    (int (-12 5 buff))))

(scales-init)

; Measuring
(if (catch (scales-weight-up) 'result)
  (println "Weight: " result)
  (println "No link."))

[Robert Gorenc]

thanx,

something similar was my idea, but I need read and write access, so my doubt is open two pipes, one for reading and one for writing, or one with r/w......

something like:

(set 'hin (open "/dev/ttyUSB0" "r"))

    (read hin buff 40)

    (close hin)

and

(set 'hout (open "/dev/ttyUSB0" "w"))

    (write-buffer hin buff )

    (close hout)



or

(set 'hndl (open "/dev/ttyUSB0" "u"))

    (write-buffer hndl buff)

    (read hndl buff 40)

    (close hndl))



I will try what is better working for me.

(exit)

[electrifiedspam]

My ultimate goal is to write a modbus module for newlisp.

My immeadiate goal is to find the comport. I know that I have com1, yet I can't find it.



I found "this" code:

-----------------------------------------------------------------

Return TRUE if the COM exists, FALSE if the COM does not exist

Public Function COMAvailable(COMNum As Integer) As Boolean

    Dim hCOM As Long

    Dim ret As Long

    Dim sec As SECURITY_ATTRIBUTES



    'try to open the COM port

    hCOM = CreateFile("COM" & COMNum & "", 0, FILE_SHARE_READ + FILE_SHARE_WRITE, sec, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0)

    If hCOM = -1 Then

        COMAvailable = False

    Else

        COMAvailable = True

        'close the COM port

        ret = CloseHandle(hCOM)

    End If

End Function

--------------------------------------------------------------------------------

Which is C and I tried to convert it to this code:



(define FILE_SHARE_READ 0x00000001)

(define FILE_SHARE_WRITE 0x00000002)

(define OPEN_EXISTING 3)

(define FILE_ATTRIBUTE_NORMAL 0x80)

(import "kernel32.dll" "CreateFileA")

(import "kernel32.dll" "CloseHandle")

(setq test1 (CreateFileA "COM1" 0 (+ FILE_SHARE_READ FILE_SHARE_WRITE) sec OPEN_EXISTING FILE_ATTRIBUTE_NORMAL 0))

(if (> test1 -1) ((println "Who's you daddy " test1) (CloseHandle test1)))



Which always returns a -1 indicating that com1 does not exist.



This leads me to believe that I am not packing my variables right. Any pointers?

[electrifiedspam]

I think I found the problem.



The 'sec' in the CreateFile attribute was allowed to be null so I packed it as a null character like this:



(constant 'sec (pack "nn" nill))



Below is the code that detected COM1.



(constant 'FILE_SHARE_READ 0x00000001)

(constant 'FILE_SHARE_WRITE 0x00000002)   

(constant 'OPEN_EXISTING 3)



(constant 'sec (pack "nn" nill))



(constant 'FILE_ATTRIBUTE_NORMAL 0x80)

(import "kernel32.dll" "CreateFileA")

(import "kernel32.dll" "CloseHandle")

(setq test1 (CreateFileA "COM1" 0 (+ FILE_SHARE_WRITE FILE_SHARE_READ) sec OPEN_EXISTING FILE_ATTRIBUTE_NORMAL 0))

(cond ((> test1 -1) (println "COM1 is present " test1) (CloseHandle test1))

         (true (println "sorry Charley"))

)



This could easily be modified to detect all available com ports. I hope this is of help to someone. Now I am on to actually reading from the comport.