FreeBasic and Arduino communication

[BasicCoder2]

Came across this which gave an Arduino example I needed to use with MrSwiss's terminal program.

http://forums.trossenrobotics.com/tutor ... rial-3300/

Now I work need to work through MrSwiss's terminal program to get it clear in my mind what is happening on the FreeBASIC side of the communication and how to write my own stuff. I haven't used the COM OPEN thingy before. It appears to be like writing/reading a file.

Running MrSwiss's terminal program and the Arduino code below I could type in a number (I assume a string) and it was returned as expected.

Code: Select all

int serialData = 0;

void setup()
{
  Serial.begin(9600);  'start serial connection at 9600 baud rate
}

void loop()
{
  if (Serial.available() > 0)    'check if serial port available
  {
    serialData = Serial.read();  'read any data
    Serial.println(serialData);  'send it back to sender
  }  
}

[caseih]

Oh good. Yes was the kind of thing I had in mind. Yes serial is just like normal input and output, nearly at least. Basic has always been good at that sort of thing.

[D.J.Peters]

@BasicCoder2 you don't have to reinvent the wheel again I wrote it 10 years ago.
Event driven RS232 class (windows)

Joshy

[BasicCoder2]

@Joshy,

Thanks. Over the next few weeks I hope to get my head around this FreeBasic and Arduino serial port communication well enough to use it with the Arduino. I have never really looked at it before as up to now I was happy using the k8055 to connect the pc to motors and sensors. For some Arduino projects wireless connections to a FreeBASIC program might also be useful. Of course I should just learn Python and be done with it but I just didn't warm to that language after a few attempts at learning it.
.

[MrSwiss]

... type in a number (I assume a string) ...

You are assuming wrong, it gets sent Byte by Byte.
REASON: my Ardino-Sketch is using a Short (16bit Integer) to store incoming stuff.
A String would 'blow' that ...

In order for you to check FB-Terminal's Code in an easier Way:

• I've simplified it to be Windows only (a lot less Code)
  better contrast (the Eyes are not any longer, what they used to be)
  no more conditional compiling Directives etc. etc. see comments

FB-Terminal.bas:

Code: Select all

' FB-Terminal.bas
' FB-Terminal.exe - Windows only
' original code by: dasyar, FreeBASIC-Forum
'
' =================================================
' MrSwiss changes: 2016-02-18 / 24
' - renamed from FBterm.bas to FB-Terminal.bas
' - Windows only (deleted all Linux related stuff)
' - NO more conditional compiling directives
' - reformated code for "readability"
' - rewritten Printing Routine ( colrPrtPos() )
' - changed colors for more contrast
' - changed Button Positions (better distribution)
' - converted If Then Else EndIf to single Line IF
'   (where it makes sense)
' - added comments (where needed)
' - replaced Integer(s) with Long(s), for FBC x64
' - deleted all unneccessary "$" on keywords
' =================================================

Screen	12
Width	80, 30
Locate	,, 1

' Globals
Dim Shared As Double	t
Dim Shared As Long		column, row, pos1, pos2, row1, column1
Dim Shared As String	Key, buffer, numtosend
Dim Shared As UByte		numtosend2
' Locals
Dim As Long		b=4, p=2, e=1	' prefered startup: "9600", "COM3:", "On"
Dim As Boolean	flag			' typical use of Boolean(s)
Dim As String	baud(0 To 7) = {"1200","2400","4800","9600","19200","38400","57600","115200"}
Dim As String	port(0 To 9) = {"COM1:","COM2:","COM3:","COM4:","COM5:","COM6:","COM7:","COM8:","COM9:","COM10:"}
Dim As String	echo(0 To 1) = {"Off"," On"}
Dim As String	Escape = Chr(27)
Dim As Long		res, x, y, buttons

''''''''' Headers for Functions and Subroutines '''''''''''
Declare Sub InfoBar	()
Declare Sub InfoBar2()
Declare Sub ColrPrtPos(	ByVal row As Long, ByVal col As Long, ByVal Stg As String, _
						ByVal CFG As ULong=&hFF000000, ByVal CBG As ULong=&hFFFFFFFF )
Declare Sub TextCursor(	ByRef flag As Boolean )	' hand flag over, instead of 'Shared' declaration
Declare Sub sendnum	()

''''''''' Start of Program ''''''''''''
Cls
begin:
InfoBar()

ColrPrtPos(2,24,port(p),15,9)
ColrPrtPos(2,41,baud(b),15,9)
''''''''' Main Screen '''''''''''''''''
Do
	res = GetMouse (x, y, , buttons)
	Key = InKey
	If Key = Escape Then Exit Do
	''''''''''' Mouse over Quit '''''''''''
	If x > 1 And x <= 32 And y > 16 And y < 31 And buttons And 1 Then GoTo Cend
	'''''''''' Mouse over Connect '''''''''
	If x > 49 And x <= 112 And y > 16 And y < 31 And buttons And 1 Then
		Sleep 200,1
		Exit Do
	End If
	'''''''''' Mouse over port ''''''''''''
	If x > 144 And x <= 176 And y > 16 And y < 31 And buttons And 1 Then
		p += 1
		If p = 10 Then p = 0
		ColrPrtPos(2,24,space(10),,9)
		ColrPrtPos(2,24,port(p),15,9)
		Sleep 200,1
	End If
	'''''''''' Mouse over baud ''''''''''''
	If x > 280 And x <= 312 And y > 16 And y < 31 And buttons And 1 Then
		b += 1
		If b = 8 Then b = 0
		ColrPrtPos(2,41,space(8),,9)
		ColrPrtPos(2,41,baud(b),15,9)
		Sleep 200,1
	End If
Loop
''''''''' End of Main Screen ''''''''''

''''''''' Live Terminal '''''''''''''''
InfoBar2()
View Print 1 To HiWord(Width)
ColrPrtPos(2,54,echo(e),15,9)
View Print 3 To HiWord(Width)
Color 7, 0 : cls

Open Com port(p) & baud(b) & ",n,8,1,cs0,ds0,cd0,rs" as #1
'' Open Com "COM1:115200,n,8,1,cs0,ds0,cd0,rs" As #1
If Err <> 0 Then
	ColrPrtPos(3,1,"Error opening " & port(p),14,0)
	Sleep 2000,1 : Cls : GoTo begin
End If


Do

	res = GetMouse (x, y, , buttons)
	Key = InKey
	TextCursor(flag)
	'''''''''' Mouse over Disconnect '''''''''
	If x > 49 And x <= 128 And y > 16 And y < 31 And buttons And 1 Then
		Close #1 : Color 7, 0 : Cls
		Sleep 200,1 : GoTo begin
	End If
	''''''''' Mouse over echo '''''''''''''
	If x > 384 And x <= 416 And y > 16 And y < 31 And buttons And 1 Then
		e += 1 : If e > 1 Then e = 0
		View Print 1 To HiWord(Width)
		ColrPrtPos(2,54,space(4),,9)
		ColrPrtPos(2,54,echo(e),15,9)
		View Print 3 To HiWord(Width)
		Color 7,0 : Cls : Sleep 200,1
	End If
	''''''''' Mouse over Send Number ''''''
	If x > 500 And x <= 582 And y > 16 And y < 31 And buttons And 1 Then sendnum()
	''''''''' Mouse over Cls ''''''''''''''
	If x > 600 And x <= 624 And y > 16 And y < 31 And buttons And 1 Then
		View Print 3 To HiWord(Width)
		Color 7, 0 : Cls : Sleep 200,1
	End If
	'''''''''' Terminal Screen ''''''''''''
	Color 7, 0
	If Key <> "" Then
		If Key = Chr(13) Then	' Check for CR
			Print #1, Chr(13);	' Send CR
		Else
			Print #1,Key;
			If echo(e) <> "Off" Then Print Key + " ";	' add a space after command
		End If
	End If

	While LOC(1) > 0
		buffer = Input(LOC(1),#1)
		Print buffer;
	Wend

	Sleep 1
Loop
''''''''' End of Live Terminal ''''''''
Cend:
Close
End
''''''''' End of Program ''''''''''''''

''''''''' Functions and Subroutines '''
Sub InfoBar()
	Cls
	Locate 1,1
	View Print 1 To HiWord(Width)
	ColrPrtPos(2, 1,Space(80),15,9)
	ColrPrtPos(1, 1,Space(80),15,9)
	ColrPrtPos(1,36,"FB-Terminal",15,9)
	ColrPrtPos(2, 1,"Quit",15,4)
	ColrPrtPos(2, 7,"Connect",15,4)
	ColrPrtPos(2,19,"Port",15,4)
	ColrPrtPos(2,36,"Baud",15,4)
	Color 7, 0
End Sub

Sub InfoBar2()
	View Print 1 To HiWord(Width)
	ColrPrtPos(2, 1,Space(80),15,9)
	ColrPrtPos(2, 7,"Disconnect",15,4)
	ColrPrtPos(2,49,"Echo",15,4)
	ColrPrtPos(2,54,"Off",15,9)
	ColrPrtPos(2,63,"Send Number",15,4)
	ColrPrtPos(2,76,"Cls",15,4)
	View Print 3 To HiWord(Width)
	Color 7, 0
End Sub

Sub ColrPrtPos(	ByVal row As Long, _
				ByVal col As Long, _
				ByVal Stg As String, _
				ByVal CFG As ULong = &hFF000000, _
				ByVal CBG As ULong = &hFFFFFFFF )
	If CFG <> &hFF000000 OrElse CBG <> &hFFFFFFFF Then Color(CFG, CBG)
	Locate row, col : Print Stg;	' NO LF invoked!
End Sub

Sub TextCursor(ByRef flag As Boolean)	' recoded MrSwiss
	column = Pos
	row = CsrLin
	If Timer - t > .5 Then
		flag = Not(flag)
		If flag Then Print "_" Else Print " ";
		Locate row,column
		t = Timer
	End If
End Sub

Sub sendnum()
	Input "Enter a number to send (0 - 255) space delimited";numtosend
	pos1 = InStr(numtosend, " ")
	If pos1 = 0 And Len(numtosend) > 0 Then
		Print #1, Chr(Val(numtosend));
		Print Chr(Val(numtosend));
	Else
		numtosend2 = Val(Left(numtosend,pos1))
		Print #1, Chr(numtosend2);
		Print Chr(numtosend2);
		Do While pos1 > 0
			pos2 = pos1
			pos1 = InStr(pos1+1, numtosend, " ")
			numtosend2 = Val(Mid(numtosend,pos2+1,pos1-pos2))
			Print #1, Chr(numtosend2);
			Print Chr(numtosend2);
		Loop
	End If
	''''''''' Get rid of garbage char '''''
	row1 = CsrLin ' Get row position
	column1 = Pos ' Get column position
	Locate row1,(column1-1)
	Print " " ' Get rid of garbage char
	Locate row1,(column1-1)
End Sub

[BasicCoder2]

@MrSwiss,

I had already stripped your code example to it's bare bones :)

FreeBasic code:

Code: Select all

Dim Shared As String   Key, buffer

Cls

Open Com "COM9:9600,n,8,1,cs0,ds0,cd0,rs" As #1
If Err <> 0 Then
   Print "Error opening COM9"
   Sleep 2000,1
   Cls
   end
End If

Do
   Key = InKey

   If Key <> "" Then
      If Key = Chr(13) Then   ' Check for CR
         Print #1, Chr(13);   ' Send CR
      Else
         Print #1,Key;
      End If
   End If

   ' When used with a serial device, LOC returns the number of bytes
   ' waiting to be read from the serial device's input buffer.
   While LOC(1) > 0
      buffer = Input(LOC(1),#1)
      Print buffer;
   Wend

   Sleep 1
Loop until Key=chr(27)


Close #1

sleep

This is the Arduino test code which turns the pin13 LED on with an 'a' key and off if you enter a 'b' key.

Arduino code:

Code: Select all

int serialData = 0;

void setup()
{
  Serial.begin(9600); 
  pinMode(13,OUTPUT); 
}

void loop()
{
  if (Serial.available() > 0)
  {
    serialData = Serial.read();
    if (serialData == 97)
       digitalWrite(13,HIGH);

    if (serialData == 98)
       digitalWrite(13,LOW);
        
    Serial.println(serialData);  // return data
  }  
}

[MrSwiss]

@BasicCoder2,

you seem to get "into it" :-)

I've had a look at the Python stuff you've mentioned recently (only the Sketch), Servo-Control.
It proofed to be "full of Beans", e.g. missing bracketing and so on, so I've given it a work-over:

Code: Select all

#include <Servo.h>          // include the Servo-Library

Servo myservo;              // define a Servo-Object 
int angle = 0;              // a Short in FB (16bit)
int newAngle = 0;           // dito
const byte MaxChars = 4;    // a Const Byte in FB (8bit)
char strValue[MaxChars+1];  // a fixed size 'ZString * 5' in FB (4 + Terminator)
byte index = 0;             // a Byte in FB (8bit)

void setup() {
  Serial.begin(9600);       // set serial speed (in Baud)
  myservo.attach(10);       // define the servo's Pin
  angle = 90;               // define start position of servo (Center)
}                           // the working range of the servo is: 0 to 180

void loop() {
  // do: nothing
}

void serialEvent() {  
  while(Serial.available()) {
    char ch = Serial.read();
      // if negative, the remaining positive is set! (on next run)
      // therefore, the 'controlling program' MUST prevent that!
      if(index < MaxChars && isDigit(ch)) {
        strValue[index++] = ch;
      } else {
        strValue[index] = 0;
        newAngle = atoi(strValue);
        if(newAngle < 181) {    // 180 is a valid input! fixed!
          if(newAngle < angle) {
            for(; angle > newAngle; angle -= 1) {   // step size = -1
              myservo.write(angle);
              // maybe a small 'delay(2);' or similar needed
            }
          } else {
            for(; angle < newAngle; angle += 1) {   // step size = +1
              myservo.write(angle);
              // maybe a small 'delay(2);' or similar needed
            }
          } 
        } else {
          Serial.write(64);     // indicate 'above max. value' prepend "@"
        }
        Serial.write(strValue); // return new Angle setting (if any)
        // Serial.write(10);       // append a LF (line feed) to show 'finished'
        index = 0;
        angle = newAngle;
      }
   }
}

The corresponding FB-Code, call it 'Servo.bas' if you like:

Code: Select all

' Servo.bas -- (c) 2016, MrSwiss
' tested: FBC for WIN64 ver. 1.05.0 + Arduno AVR 168 / 16 KHz

ReDim As String		inpLine(1 To 1)	' dynamic string array (stores Servo.txt)
Const As String		inFile = "Servo.txt"
Dim As Long 		inFileNo, LineCnt = 0
Dim As Boolean		ErrExit

inFileNo = FreeFile
Color 15, 4 : Cls

If Open (ExePath+"\"+inFile For Input As #inFileNo) Then	' "Servo.txt" must be in EXE-DIR!
	Cls : Locate 2, 2
	Print "ERROR: opening file "+ExePath+"\"+inFile+", aborting ..."
	ErrExit = TRUE
Else
	Locate 2,2 : Print "OPEN: '"+inFile+"' success!"
End If
If ErrExit Then Close inFileNo : Sleep : End	' on "Open File"-Error quit prog.

Do Until Eof(inFileNo)		' read whole file, line by line until EOF OR preset max-len
	LineCnt += 1			' starts at 1 (0 + 1 = 1, see inpLine()/LineCnt declarations)
	Line Input #inFileNo, inpLine(LineCnt)	' read one line into string array
	ReDim Preserve inpLine(1 To LineCnt+1)	' append a new string to array, keep content
	If LineCnt > 2500 Then	' set array-max. to 2500 strings
		LineCnt = 2500		' adjust array line counter (-1), important !
		Exit Do				' get out of do/loop NOW !!!
	EndIf
Loop
ReDim Preserve inpLine(1 To LineCnt)	' throw away 'empty' string !
Close inFileNo							' always close opened file, if no longer required
Dim As Const Long maxLine = LineCnt		' remember the max. LineCnt

' ====================================================================== '
' Serial Communication starts here:
' ---------------------------------------------------------------------- '
' Contrary to FB-Terminal:
' ~~~~~~~~~~~~~~~~~~~~~~~~
' Send / Receive works with short Strings (ZString * 5 for sending),
' receiving String Lenght varies, see Explanation on LOC().
' ====================================================================== '

inFileNo = FreeFile			' re-use of declared var.

Open Com "COM3:9600,N,8,1,cs0,ds0,cd0,rs" As inFileNo	' change as needed!
If Err Then
	Locate 2,2 : Print "OPEN: 'COM3:9600,N,8,1' failed!"
	Sleep : Close inFileNo : End
Else
	Locate 2,42 : Print "OPEN: 'COM3:9600,N,8,1' success!"
EndIf

View Print 4 To 25			' Console setup ...
Color 14, 1 : Cls
Sleep 2000, 1				' give some Time to establish Connect ...

' below: NOT to be confused with OS-/HW-Buffers (they can't be controlled from here!)
Dim As ZString * 5 	sendStr = ""	' TX-Buffer (transmit/send)
Dim As String 		buffer  = ""	' RX-Buffer (receive)


Do
	LineCnt	= 1				' re-use of declared var.

	While LineCnt < maxLine+1		' run until the End of String Array
		sendStr = inpLine(LineCnt)	' get TX-Buffer (Cmd_Line from StringArray (max. 4 Byte))
		If CLng(sendStr) < 0 Then sendStr = ""	' don't allow negative values, see Sketch!
		Print "FB: " + sendStr;		' suppress LF (we want Arduino's Response on the same Line!)
		Print #inFileNo, sendStr	' send Command String to Arduino
		LineCnt += 1		' prepare array index for next run
		Sleep 300, 1		' give Arduino Time to answer ...
		If LOC(inFileNo) > 0 Then	' LOC() returns Number of Bytes to read
			buffer = Input(LOC(inFileNo), #inFileNo)	' read Serial-Buffer (into our own)
			Print " A: " + buffer	' show the Response from Arduino
		Else
			Print " A: ???"	' if we didn't get anything from Arduino, _
		End If				' this may happen at Communication Start!
		buffer = ""			' clear RX-Buffer for next run
	
		Sleep 700, 1		' run approx. once a Second (a new Command)
	Wend

	Print "~~~~~~~~~~~~~~~~~~~~~~~"	' indicate end of Data reached ... restart	

	Sleep 2000, 1			' wait 2 Seconds before re-Start
Loop Until InKey() = Chr(255) + "k"	' click the X to quit Program

Close inFileNo				' always close opened COM-PORT, if no longer required
View Print 1 To 25			' reset Console to default
Color 7, 0 : Cls			' Color dito
End							' quit

Below the 'Servo.txt' File needed by 'Servo.exe':

Code: Select all

120;
90;
180;
140;
110;
70;
30;
0;
90;

The values (and their Number) can be changed any Time, just for Test's.

Explanations:

• Servo.txt is read (in full) into Memory and thereafter released.
  It contains what could be called: Aduino-Commands (Servo Position).
  This Example is sending/receiving String (unlike the other Examples posted before).
  I've written detailed Comments in the respective Code-Files

If there are still Questions, just ask ...

[BasicCoder2]

@MrSwiss,

Something amiss as all the servo does is twitch with each change except for a big move clockwise at the start and a big move anticlockwise (back to start position I assume) with the program exit.

Screen outputs.
FB: 120; A: 120; ' big move

FB: 90; A: 90; 'twitch

FB: 180; A: 180 'twitch

and so on ....

One problem I did have with another Arduino servo example was it would move back and forth a few times as it was programmed to do and then freeze. Giving the board its own power supply instead of using the USB power supply seemed to fix that.

.

[MrSwiss]

@BasicCoder2,

yes it is probably a Power issue, since the Guy who posted the original Sketch mentioned
using a Motor Driver Shield (which would take the Strain off the Arduino).
Alternative a powered USB-Hub, or as you mentioned, a separate Power Supply.

The Servo might also not support the 1° Steps. You'd have to check Doc. of Servo for min.
Step-Size and so on. With bigger Steps you might have to use a Delay (as in Comments).

[BasicCoder2]

@MrSwiss,

Inserting a delay(1) fixed the problem.

When I used delay(2) I got a strange result.

FB: 120; A: 120
FB: 90; A: 90
FB: 180; A: ???
FB: 140; A: 180140
FB: 110; A: 110
FB: 70; A: 70

And larger delays gave other strange results.

I find the need for a delay less than robust although I see it used that way in other example code.

Although there are lots of interesting stand alone projects for the Arduino my interest involves the power of a pc and the ease of using FreeBASIC.
The arduino is then just used as an intelligent usb interface for any FreeBASIC hardware project.

.

[caseih]

As it happens I've been writing some FB code today to read serial data from a device I'm working on. More or less equivalent to what you are doing. The device is an Atmel device, but it's not Arduino. I had to reverse engineer their protocol, which wasn't too difficult.

I'm using input(#sp,1) to read 1 byte at a time. I've found that input() blocks if there's no bytes forthcoming on the serial port, which is usually fine. I've discovered that a keystroke (at least in graphics mode; not sure about console mode) will cause input() to return an empty string, which works well for me because I can then check inkey to look at the keystroke. So my program can be more or less interactive. But I read that lof() should return the number of bytes waiting in the serial port buffer. However on my Linux machine this always returns 0. It would be nice if this worked, as I could then implement a timeout to do some background tasks like update the screen, and some other things.

Is this a bug perhaps, specific to Linux?

[MrSwiss]

@BasicCoder2,

the Output you've posted indicates that:

Sleep 300, 1 ' give Arduino Time to answer ... (in FB Prog.)

is probably set a bit to short [for: delay(2);], since it is something like, roughly:
(try [500, 1], + subtract added value from the second Sleep, before the 'Wend')

((singleStep + StepDelay) * StepNumbers) + "Margin"
Margin = Time for running Prog. + Communication Overhead + Delay

Communication Overhead: might be reduced by 'upping' the Baud-Rate, e.g. 19'200.
I've run my Arduino up to: 115'200 Baud ... (the Setting in Properties: COM-PORT).

You'd probably have to find out empirically, e.g. Trial & Error Method.


@caseih,

I'm using LOC() to get the Number of Bytes to read (from Serial Buffer "OS").
Don't know about LOF()? Isn't this more Keyboard-Buffer related? CR&LF/LF Stuff?
Since I'm on WIN, I've no (in Depth) Information about HW Treatment in UX/LX.

[caseih]

I'll try it out, MrSwiss. The docs indicate lof() is the proper call as it's supposed to return the number of bytes unread in the buffer. loc() returns the current read position in the file, with no mention of what it does with a serial port. I'll give it a shot. EDIT: Yes it seems to work as a trigger. loc() returns 0 when the buffer is empty, and when it's full, it counts up.

[MrSwiss]

... file, with no mention of what it does with a serial port.

@caseih, your Manual is probably outdated.

(from Manual 1.05.0) [LOC()] Description: When used with a serial device, LOC returns the number of bytes waiting to be read
from the serial device's input buffer.
It even has a Example with Serial ... Alternative: see Online-Doc (The most up-to-Date Version, in any Case).

[caseih]

Ahh yes. So it does. Lof()'s page says something similar, which is why I tried it first, but it doesn't work, at least under Linux.