Serial port UDF / COM port UDF

[MazeM]

Hi

here's another UDF for the serial port. It is very similar to CommAPI using kernel32.dll, but all code is packed into a single file without any dependencies, not even using WinAPI.au3. It differs from existing UDF that it doesn't allow a timeout when reading, instead it always returns immediately, either with the requested amount ob bytes read or with a failure status. And of course there is a function provided to query the amount of available bytes in the receive buffer. The reason behind this design decision: You can do 1000 other things in the main loop while checking from time to time if enough data bytes arrived. There's no point to block the program waiting for the serial port.

It is currently a work-in-progress, as I didn't test all functions yet. The code was developed and tested on Windows 7 64 bit.  The ComUDF-Tests.au3 shows some tests and basic usage of the UDF. Maybe there's no reason to use this UDF, given the existence of the others UDFs, but I did it to get to know DllCall better - I use structs no only to pass but also to get data back (I don't use the array returned by DllCall to read that data, unless required). You're welcome to test it on older and newer Windows versions.

Here's a list of the implemented functions:

; _ComListPorts
; _ComOpenPort
; _ComSetTimeouts
; _ComClosePort
;
; _ComSetBreak
; _ComClearBreak
; _ComGetInputcount
; _ComGetOutputcount
; _ComClearOutputBuffer
; _ComClearInputBuffer
;
; _ComSendByte
; _ComReadByte
; _ComSendBinary
; _ComReadBinary
;
; _ComSendChar
; _ComReadChar
; _ComSendCharArray
; _ComReadCharArray
; _ComSendString
; _ComReadString
;
; __ComClearCommError
; __PurgeComm

Maze

 

ComUDF.au3

ComUDF-Tests.au3

Edited July 1, 2017 by MazeM
Cleaned up some comments in ComUDF.au3 and updated ComUDF-Tests.au3

[itagashu]

Hello MazeM,

Thank you for your contribution! I've discovered a couple of issues with ComUDF at the moment:

1) The following code fails to properly recognize 2 and 3-digit COM ports on both 1x Win7 64-bit PC and 5x Win10 64-bit laptops. Anything past the first digit is simply ignored (odd because the code seems fine to me...).

;extract $comPort from $defs
   $comPort = StringLeft($def, 4)      ;"com1".."com9" (com plus 1st digit)
   If IsNumber(StringMid($def, 5)) Then ;"com10".."com99" (2nd digit)
      $comPort &= StringMid($def, 5)
      If IsNumber(StringMid($def, 6)) Then ;"com100".."com256" (3rd digit)
         $comPort &= StringMid($def, 6)
      EndIf
   EndIf

2) Windows uses UNC paths for anything above COM9 (https://support.microsoft.com/en-us/help/115831/howto-specify-serial-ports-larger-than-com9), so any 2 and 3-digit strings generated by the code above would be invalid. It is recommended to append "\\.\" to every COM port number.

 

Fortunately, the following code was tested on the above systems and will remedy the issues above completely by a) utilizing StringIsDigit/StringTrimLeft instead of IsNumber/StringMid and  appending a prefix of "\\.\" to any COM port between 1 and 256.

;extract $comPort from $defs
   $comPort = "\\.\" & StringLeft($def, 4)      ;"com1".."com9" (com plus 1st digit)
   If StringIsDigit(StringLeft(StringTrimLeft($def, 4), 1)) Then ;"com10".."com99" (2nd digit)
      $comPort &= StringLeft(StringTrimLeft($def, 4), 1)
      If StringIsDigit(StringLeft(StringTrimLeft($def, 5), 1)) Then ;"com100".."com256" (3rd digit)
         $comPort &= StringLeft(StringTrimLeft($def, 5), 1)
      EndIf
   EndIf

itagashu

[x2norm]

I would appreciate some help. When i try to use  _ComListPorts() to get a list of  com ports in an array it always comes up blank. What am i doing wrong? In fact the Array display does not even open up a window. The script end without an error. 

#include <Array.au3>
#include <comUDF.au3>

Local $ports = _ComListPorts()
_ArrayDisplay($ports)

 Can anyone help? 

[itagashu]

x2norm,

What do you see under the Ports (COM & LPT) section of device manager?

itagashu

[Ara]

Hi There,

I'm trying to read from my Com port but I can't.

I'm able to send it successfully and i know that my com port gets the characters (tried it with TeraTerm) but when i try to read the COM port with Auto it it just gives me 0.

Following is my code to read the Com port

Func    FUNC_021_Read_From_Com($i_com_num)

   Local $ports = _ComListPorts()
   Local $ports_arry = _ComListPorts()          ;an array with com ports
   Local $s_ComPort='COM' & $i_com_num          ;a com port, e.g. COM1
   Local $s_Def='baud=57600 data=8 parity=n stop=1' 
   Local $h_ComPort ;serial port handle
   Local $s_Info = 'cbOutQue'
   Local $i_num_chars = 16
   Local $b_rtn
   Local $i_Length
   Local $i_comp
   Local $s_Readstr


   $h_ComPort = _ComOpenPort($s_ComPort & $s_Def)

   if ($h_ComPort <> 0) Then

      __PurgeComm($h_ComPort, '0x000F')
      __ComClearCommError($h_ComPort,$s_Info)


      Sleep(5000)
      $s_Readstr = _ComReadString($h_ComPort, 26, 2)    
      MsgBox($MB_OK," Programming Serial Number!"," This is What I Get: " & $s_Readstr) ; I Get 0

      _ComClosePort($h_ComPort)
   
   EndIf

EndFunc

Any suggestion is appreciated

Thank you

[mLipok]

Just found this UDF.
Thanks for sharing.

Added to UDF List on WIKI:
https://www.autoitscript.com/wiki/User_Defined_Functions#Hardware

[Ara]

Thank you @mLipok my problem was timing, I was reading it too late

[mLipok]

Refactored version:

ComUDF.au3.zip

Edited September 21, 2020 by mLipok

[mLipok]

new version of UDF V2.92
and Improved Example:

 

ComUDF.zip

Edited September 23, 2020 by mLipok

[Chuckero]

I'm doing a small update over the V2.92 based on the @itagashu comments. I couldn't use COM10 under Windows 10 64bits.
ComUDF V2.93:

- COM port numbers above 9;

- Keeping two examples.
 

 

ComUDF_V293.zip

[mLipok]

I think this will be moved..... as I and @Danyfirex are working on update....

Quote

   V2.93
   Danyfirex 23/09/2020
        * Change variables naming to fit AutoIt convention
        * Fixed DllCall return check
        * changed function name __PurgeComm >> __COM_Purge
        * fixed many function to start it works
   V2.94
   Danyfirex 25/09/2020
        * small fixes
   V2.95
   Danyfirex 28/09/2020
        * modified function _COM_SendString - now it use _COM_SendBinary instead _COM_SendCharArray
   V2.96
   mLipok 28/09/2020
        * small refactoring/cleaning
 

But as so far we not publish our modified version so your mod will be about V2.97 if you do not have any objections.
I hope we post this in next few days toogether with your fix.

EDIT 1:
As I said we not publish our modified version, because we are working on some other project which is realted to this UDF.
I hope this other project will also be published here but it need times.

 

Edited September 30, 2020 by mLipok

[mLipok]

I comunicate with @Danyfirex as to his problem with power and Internet we comunicate mostly by WhatsApp, in our project this is more accurate.
He said that he aleady fixed that, yeasterday with regexp.

I attach current version

Quote

   V2.91
   21/09/2020
        * refactoring  + AU3Check compiliance - mLipok
   V2.92
   23/09/2020
        * small changes - mLipok
        * better error/extended reporting - mLipok
        * better example - mLipok
   V2.93
   23/09/2020
        * Change variables naming to fit AutoIt convention - Danyfirex
        * Fixed DllCall return check - Danyfirex
        * changed function name __PurgeComm >> __COM_Purge - Danyfirex
        * fixed many function to start it works - Danyfirex
   V2.94
   Danyfirex 25/09/2020
        * small fixes - Danyfirex
   V2.95
   28/09/2020
        * modified function _COM_SendString - now it use _COM_SendBinary instead _COM_SendCharArray - Danyfirex
   V2.96
   28/09/2020
        * small refactoring/cleaning -  mLipok
   V2.97
   29/09/2020
        * fixed function _COM_OpenPort() - open port above 9 (the same issue which @Chuckero posted to the forum in 30/09/2020 as V2.93) - Danyfirex

 

ComUDF.au3

Edited October 7, 2020 by mLipok

[Chuckero]

54 minutes ago, mLipok said:

I comunicate with @Danyfirex as to his problem with power and Internet we comunicate mostly by WhatsApp, in our projtect this is more accurate.
He said that he aleady fixed that, yeasterday with regexp.

I attach current version

Cool! Great job!

[mLipok]

Related content:

 

[mLipok]

On 9/30/2020 at 10:20 PM, mLipok said:

As I said we not publish our modified version, because we are working on some other project which is realted to this UDF.
I hope this other project will also be published here but it need times.

Here we post our work:

 

and here is support topic:

 

 

[mLipok]

btw.
In ATCmd.au3 there is newer version of ComUDF.au3 UDF:

Quote

V2.98
01/10/2020
    * added function _COM_ListPortDevices - List Port Devices 2DArray - Danyfirex

 

[Filipp_G]

Unlimited thanks to creator of this UDF and other who took part in this!!!

Can I asked question and also suggest one thing (in case of positive answer on this question)?:
Does this UDF involves that you can connect to several COM ports in one application? If it does, there is a little problem. Let me explain more detaily:
For example, I have two COM ports (COM1 and COM2) in my system and I want to use them both at one time in my application. So I do next:
1) open COM1 port using function and according definition:     $hCom1Open = _COM_OpenPort("COM1 baud=9600 parity=N data=8 stop=1")
2) open COM2 port using:     $hCom2Open =  _COM_OpenPort("COM2 baud=9600 parity=N data=8 stop=1")
3) then I can use both my handles of opened ports as I need (receive and send data)
4) now I need to close one port (for example COM2). I do it successfully with function _COM_ClosePort($hCom2Open)
5) and now I can do nothing with opened port $hCom1Open, including receiving, send data and also it is impossible to close the handle:     _COM_ClosePort($hCom1Open) returns -1
As I see, this all because of global variable $__g_hCOMUDF_Kernel32 which is get its value during DllCall when opening port:     $__g_hCOMUDF_Kernel32 = DllOpen('kernel32.dll').
When you close port, the common handle ( $__g_hCOMUDF_Kernel32) of DllCall also terminated. This seen from function _COM_ClosePort():     DllClose($__g_hCOMUDF_Kernel32).
 

So my suggestion is to add a handles counter of each opened port. For example, to do it this way:
1) add a variable near global variables definition:     Global $__g_hCOMUDF_Kernel32, $i_h_Count = 0
2) in _COM_OpenPort replace line of __g_hCOMUDF_Kernel32 defiinition:     If $i_h_Count = 0 Then $__g_hCOMUDF_Kernel32 = DllOpen('kernel32.dll')
3) before the last line (Return value) in _COM_OpenPort function add this line:     $i_h_Count = $i_h_Count + 1
4) in function _COM_ClosePort replace line of DllClose by two lines:
$i_h_Count = $i_h_Count - 1
If i_h_Count = 0 Then DllClose($__g_hCOMUDF_Kernel32)

After those steps (as I tried to do in my app) you can open several COM ports and work with them without any problems even if one or more will be closed later.

Please, I will be very appreciated if you will comment my question and my suggestion. As for me, understanding calls of CreateFile is not so easy. That's why I'm not sure if I correctly using this UDF and work with serial ports at all. Especially due to never worked in C++. My experience in programming started and continues only in AutoIt.

[Chuckero]

Hello @Filipp_G, I'm using this library pretty often, it is really helpful. I just want to say, if you already solved the problem, why not share what you have? Just increase the version number, put your comments on the beginning of the file and upload it. This way anyone can improve it.

[Filipp_G]

4 hours ago, Chuckero said:

Hello @Filipp_G, I'm using this library pretty often, it is really helpful. I just want to say, if you already solved the problem, why not share what you have? Just increase the version number, put your comments on the beginning of the file and upload it. This way anyone can improve it.

Hello, @Chuckero! Thanks for reply. Yes, it's not a problem to do this. But just one thing to ask: does everyone mind if I delete the Note section from _COM_SendString function description, which is under the spoiler?:

Spoiler

; ===============================================================================================================================
; Function Name:       _COM_SendString($hComPort, $string, $encoding=1)
; Description:        Sends data
; Parameters:         $hComPort - serial port handle (as returned by _COM_OpenPort)
;                    $string   - the string to write
;                    $encoding - 1=ANSI (default), 2=UTF-8
; Returns:          on success returns the number of bytes written
;                   on error returns -1 and sets @error to 1
; Note:
; If there are less bytes than requested in the input buffer it returns 0
; ===============================================================================================================================

As I think, this comment is not suitable for this function, because the send operation is not depend of input buffer.

[Chuckero]

On 4/8/2021 at 4:27 PM, Filipp_G said:

Hello, @Chuckero! Thanks for reply. Yes, it's not a problem to do this. But just one thing to ask: does everyone mind if I delete the Note section from _COM_SendString function description, which is under the spoiler?:

  Hide contents

; ===============================================================================================================================
; Function Name:       _COM_SendString($hComPort, $string, $encoding=1)
; Description:        Sends data
; Parameters:         $hComPort - serial port handle (as returned by _COM_OpenPort)
;                    $string   - the string to write
;                    $encoding - 1=ANSI (default), 2=UTF-8
; Returns:          on success returns the number of bytes written
;                   on error returns -1 and sets @error to 1
; Note:
; If there are less bytes than requested in the input buffer it returns 0
; ===============================================================================================================================

As I think, this comment is not suitable for this function, because the send operation is not depend of input buffer.

Yes, that comment doesn't seem to make sense.