DIY hardware interface for simple data collection and robot control?

[h4tt3n]

Do you know of an economic, software controllable piece of hardware that will allow us to flip a series of pins on/off or do measurements on them?

Yes, have a look at Arduino, or any of the many Clones: "Open Source HW", as well as
plenty possible add on Modules (for many specific tasks, such as Network, Robotics etc.).
Controlled by itself, autonomous mode (external control via VCP, serial communication).

Price here, for a Uno/Clone: 15 - 25 US$/piece (completely assembled/soldered board).
There are even special sets available, for educational purposes.

Thanks, noted! :-)

[h4tt3n]

Apart from the hardware, do you have practical (automation) ideas that the students would interest?

Yes. Most of it is pretty straight-forward. For the input part, I want to measure if a certain switch is on or off. I'd also like to measure frequency / rotations per second when comparing different pendulums / wind turbines / steam engines / DIY electromotors etc. I would also like to measure voltage as a means of comparing temperature / light / sound / generator output. For the output part, I would simply like to be able to turn stuff on and off, like a LED, relay, or thyristor.

With these basic building blocks, some scrap metal and bit of duct tape we can make almost everything.

[Gunslinger]

A lot of arduino starter kit are easy to find.
https://nl.aliexpress.com/store/1738188 ... autifyAB=5

[h4tt3n]

Hello again,

I've been looking into things and have decided on the Arduino. I have ordered an Arduino Uno and Mega and some extra shields for sensor input and motor control. The programming ide is very straight forward to use for anyone with basic programming skills, and when the mailman arrives I'll already have several test programs ready to install.
As a side note, growing up with the Commodore and Amiga computers, the lack of direct hardware access in modern pc's have become increasingly frustrating, and simply beeing able to read and write directly to a pin without having to install any libraries, drivers or bypass abstraction layers or safety measures really feels like beeing "home" again :-)

I'll keep you updated, Cheers Mike

[grindstone]

I found an interesting site:
http://vusb.wikidot.com/start

[MrSwiss]

I'll keep you updated, Cheers Mike

Well, how far is your current progress? Just curious ...

[h4tt3n]

I'll keep you updated, Cheers Mike

Well, how far is your current progress? Just curious ...

I ended up trying Arduino and wasn't disappointed. It's basically like an old Commodore 64 in a matchbox :-) For a very few quid, and spending a very little time, you've got LED's blinking and stepper motors humming about. Throw in a few rubber bands, some duct tape, scrap wood, and LEGO bricks, and you're away inventing stuff.

Cheers, Mike

[TJF]

Hi h4tt3n!

Arduino is a good choise, since newcommers can get a system running in a short time. They don't have to study lots of configuration stuff.

But it's limited when it comes to big memory or fast CPU requirements, ie. video or network tasks. And you cannot follow your initial plan

... I am planning on using FB as an integral part of my education.

Unfortunatelly nobody pointed you to the Beaglebone hardware yet. That are modern check card computers in a cost range starting at Arduino level, but running a modern CPU under LINUX. Several hardware flovours are availabe, ie.

• Pocket Beagle (headless, cheap and small)
• Green (headless with original headers)
• Green wireless (WLAN, headless with original headers)
• Black (hdmi output)
• Blue (prepared for roboting tasks)

Due to special co-processors (PRU = Programable Realtime Unit, two are available) they do not only have the same realtime capabilities as an Arduino, they are much better even when running under a non-realtime OS.

Unlike other LINUX systems the hardware configuration is as easy as on the Arduino. No setup in any system files. Instead everything gets controlled in single source from your code, when you use a special library called libpruio.

And finally this library is a FreeBASIC project. You can also use FreeBASIC for you project code, and therefor follow your original planning. (Further languages: currently C and Python.)

Do not hasitate to ask if you need further information.

Regards

[h4tt3n]

Hi TJF,

That looks really cool! :) So far I'm going to stick with Arduino because I don't really need a lot of cpu power or memory, but I really, really need it to be simple, and I need the very easy I/O functionality that allows you to add sensors, led's, motors and so on.

Cheers, and happy holidays,
Mike

[TJF]

It does not only look cool :-)

Sure, it takes a lot off effort starting a new educational job. Everything has to be prepared well, in order not to fail in the classroom. You don't need much CPU power and memory. But your students may need in future. And when you have your head free, starting to think about their needs, I hope you'll remember my proposal.

All the best for your job!

[fridlund]

Hi Ms. Swiss,
Re: the below, can you share any FB code you've written to use your LabJack U12? This looks like a simple DAQ that could work for my own lab applicaion as well. I just need the code to achieve A/D conversion of 4 channels, possibly some Digital I/O to 2 or 3 outputs. I see your application is commercial. Mine is not, but for my private university lab, and I'd be happy to sign any necessary NDA's
Many thanks,
Alan

I prefer a LabJack U12, any day (which I use for my commercial environmental Monitoring-SW).[list]

[MrSwiss]

Hi Ms. Swiss, <-- MrSwiss please (I'm not Miss Switzerland ;-) )
Re: the below, can you share any FB code you've written to use your LabJack U12?

Sorry, but no (commercial), it's also far too complex for simple use.

For simple Lab-Applications I'd use a "graphical coding environment" which most likely contains
the necessary "building-block" to access the HW. This is far simpler, than coding that sort of
thing yourself. (You'll have to link to a in C written DLL, e.t.c.)

In the LabJackU12's driver kit, there is one of them included ... (trial version, IIRC).
There are of course others like LabView(TM), to which you might already have access to, if
you're working at a University (no additional cost).

[MrSwiss]

It is also from the FBC 32 bit, only days ...
Therefore, I've tested it (q & d -- hack) if it still works, in principle.

Just as a demo, how to load the DLL and access one single Function within.
(I'd never use it that way. I'd split it into a static Lib, which the .exe loads.)

LabJack_U12-first.bas:

Code: Select all

' LabJack_U12-first.bas -- (c) 2019-10-16, MrSwiss
'
' just a quick & dirty hack to show minimal use
'

Dim As Any Ptr  LJ_lib                  ' the DLL's base address

#Ifdef __FB_64BIT__
LJ_lib = DylibLoad("C:\Windows\System32\ljackuw.dll")   ' FBC 64
#Else
LJ_lib = DylibLoad("C:\Windows\SysWOW64\ljackuw.dll")   ' FBC 32
#EndIf

If LJ_lib = 0 Then
    Print "ERROR: 'ljackuw.dll' load failed!"
    Beep : Sleep : End 1
End If

Dim LJ_AISample As Function( _          ' Declaration of Function
    ByVal idnum       As Long   Ptr, _  ' @I32
    ByVal demo        As Long,       _  ' I32
    ByVal stateIO     As Long   Ptr, _
    ByVal updateIO    As Long,       _
    ByVal ledOn       As Long,       _
    ByVal numChannels As Long,       _
    ByVal channels    As Long   Ptr, _
    ByVal gains       As Long   Ptr, _
    ByVal disableCal  As Long,       _
    ByVal overVoltage As Long   Ptr, _
    ByVal voltages    As Single Ptr  _  ' float (binary32)
    ) As Long
LJ_AISample = DylibSymbol(LJ_lib, "AISample")   ' Function Ptr

If LJ_AISample = 0 Then
    Print "ERROR: 'LJ_AISample' load failed!"
    Beep : Sleep : End 2
End If

' the whole data to be sent/aquired must be pre-allocated (dimmed)
Dim As Long     LJ_idnum = -1, _        ' use @LJ_id in call (pointer)
                LJ_demo = 0, _          ' straight use (not a pointer) real (not demo)
                LJ_stateIO(0 To 3), _   ' digital pin's: 0 .. 3 (lo = 0, hi > 0)
                LJ_updateIO = 0, _      ' default: don't update digital IO's (output)
                LJ_ledOn = 1, _         ' default: ON
                LJ_numChannels = 4, _   ' get 4 analog channels (max.)
                LJ_channels(0 To 7) = { 0, 1, 2, 3, 4, 5, 6, 7 }, _ ' SE channels (2 call's needed!)
                LJ_gains(0 To 3), _     ' not used on SE channels only differential channels
                LJ_disableCal = 0, _    ' typically: OFF
                LJ_overVoltage(0 To 7), _   ' per call only 4 needed
                LJ_idx = 0              ' helper for channels selection (0 or 4)
Dim As Single   LJ_voltages(0 To 7)     ' either @LJ_voltages(0) or @LJ_voltages(4)


If LJ_AISample(@LJ_idnum, LJ_demo, @LJ_stateIO(0), LJ_updateIO, LJ_ledOn, _
               LJ_numChannels, @LJ_channels(LJ_idx), @LJ_gains(0), LJ_disableCal, _
               @LJ_overVoltage(LJ_idx), @LJ_voltages(LJ_idx)) > 0 Then
    Print "ERROR: 'LJ_AISample' call failed!"
    Beep : Sleep : End 3
Else
    Print "AI0: "; LJ_voltages(0)
    Print "AI1: "; LJ_voltages(1)
    Print "AI2: "; LJ_voltages(2)
    Print "AI3: "; LJ_voltages(3)
    Print
    Print "D-I/O 0: "; LJ_channels(0)
    Print "D-I/O 1: "; LJ_channels(1)
    Print "D-I/O 2: "; LJ_channels(2)
    Print "D-I/O 3: "; LJ_channels(3)
End If

Sleep
' clean up: release loaded DLL
DylibFree(LJ_lib)

NOTE: it assumes a 64 bit Windows, may fail on 32 bits!

[fridlund]

Dear MrSwiss,
Thank you so much for the help. I'll give your sample code a go.
All the best,
Alan

[fridlund]

Hi MrSwiss,
It's been several weeks since you uploaded the U12 code, and I'm indebted to you sir. I managed to get it running and, folllowing your lead, some of the other U12 functions as well. I needed a scrolling plot of 4 A/D inputs with some Digital I/O for my application and so I thought I'd upload it here (below - I'll ask your forgiveness for the unprofessional coding in advance...).
Two Q's:
1. Would you mind if I uploaded this with attribution to you to the LabJack forum as well? They have almost no FB code for the U12.
2. Have you by chance done any coding for the U3-HV? I'm having some problems setting up some of the U3 functions and wonder if you have some public code available as you did for the U12.
Again, many thanks!
Alan

Code: Select all

' LabJack_U12-first.bas -- (c) 2019-10-16, MrSwiss
'
' just a quick & dirty hack to show minimal use
'
' LabJackTest for LabJack U12.
'
' Code amended with scrolling plot -- 2019-11-25, Alan J. Fridlund,
' with much thanks to MrSwiss.

SCREENRES 640,480                            ' Set up VGA resolution.
Dim As Any Ptr LJ_lib                          ' To store the U12 DLL's base address.
Dim FileNam as String
Dim I As Integer
Dim as Integer GraphCol, LeftGraphCol
Dim As Integer MaxScans, NumChan, NumScans
Dim As Integer EOState0, EOState1, EIState2, EIState3
Dim As Single LJ_Plot(4), LJ_Voltages(4), VoltTemp
Dim As String S

# Ifdef __FB_64BIT__
 LJ_lib = DylibLoad("C:\Windows\System32\ljackuw.dll")      ' FBC 64
# Else
 LJ_lib = DylibLoad("C:\Windows\SysWOW64\ljackuw.dll")   ' FBC 32
# EndIf
If LJ_lib = 0 Then
    Print "ERROR: 'ljackuw.dll' load failed!"
    Beep : Sleep : End 1
End If

Dim LJ_AISample As Function( _          ' Declaration of A/D Input Function
    ByVal idnum       As Long   Ptr, _  ' @I32
    ByVal demo        As Long,       _  ' I32
    ByVal stateIO     As Long   Ptr, _
    ByVal updateIO    As Long,       _
    ByVal ledOn       As Long,       _
    ByVal numChannels As Long,       _
    ByVal channels    As Long   Ptr, _
    ByVal gains       As Long   Ptr, _
    ByVal disableCal  As Long,       _
    ByVal overVoltage As Long   Ptr, _
    ByVal voltages    As Single Ptr  _  ' float (binary32)
    ) As Long
LJ_AISample = DylibSymbol(LJ_lib, "AISample")   ' Function Ptr
If LJ_AISample = 0 Then
    Print "ERROR: 'LJ_AISample' load failed!"
    Beep : Sleep : End 2
End If

'--------------------------------------
' Set up of these remaining functions following code by MrSwiss - AJF.
'--------------------------------------

Dim LJ_DigitalIO As Function( _          ' Declaration of Function
    ByVal Digidnum    As Long   Ptr, _  ' @I32
    ByVal demo        As Long,       _  ' I32
    ByVal trisIO      As Long,       _
    ByVal stateD      As Long   Ptr, _
    ByVal stateIO     As Long   Ptr, _
    ByVal updateDig   As Long,       _
    ByVal OutputD     As Long   Ptr  _
    ) As Long
LJ_DigitalIO = DylibSymbol(LJ_lib, "DigitalIO")   ' Function Ptr
If LJ_DigitalIO = 0 Then
    Print "ERROR: 'LJ_DigitalIO' load failed!"
    Beep : Sleep : End 2
End If

'--------------------------------------

Dim LJ_EIDigitalIn As Function( _          ' Declaration of Function
    ByVal LJ_EIidnum       As Long   Ptr, _  ' @I32
    ByVal LJ_EIdemo        As Long,       _  ' I32
    ByVal LJ_EIchannel     As Long,       _
    ByVal LJ_EIread        As Long,       _
    ByVal LJ_EIstate       As Long   Ptr  _   
    ) As Long
LJ_EIDigitalIn = DylibSymbol(LJ_lib, "EDigitalIn")   ' Function Ptr
If LJ_EIDigitalIn = 0 Then
    Print "ERROR: 'LJ_EDigitalIn' load failed!"
    Beep : Sleep : End 2
End If

'--------------------------------------

Dim LJ_EODigitalOut As Function( _          ' Declaration of Function
    ByVal LJ_EOidnum       As Long   Ptr, _  ' @I32
    ByVal LJ_EOdemo        As Long,       _  ' I32
    ByVal LJ_EOchannel     As Long,       _
    ByVal LJ_EOwriteD      As Long,       _
    ByVal LJ_EOstate       As Long        _   
    ) As Long
LJ_EODigitalOut = DylibSymbol(LJ_lib, "EDigitalOut")   ' Function Ptr
If LJ_EODigitalOut = 0 Then
    Print "ERROR: 'LJ_EODigitalOut0' load failed!"
    Beep : Sleep : End 2
End If

'--------------------------------------

' Nothing done with AOUpdate in the scrolling plot. - AJF
Dim LJ_AOUpdate As Function( _          ' Declaration of Function
    ByVal AOidnum     As Long   Ptr, _  ' @I32
    ByVal trisd       As Long,       _  ' I32
    ByVal trisIO      As Long,       _  ' I32
    ByVal stateD      As Long   Ptr, _
    ByVal stateIO     As Long   Ptr, _
    ByVal updateDig   As Long,       _
    ByVal lngResCntr  As Long,       _
    ByVal count       As Long   Ptr, _
    ByVal gains       As Long   Ptr, _
    ByVal disableCal  As Long,       _
    ByVal AnalogOut0  As Single Ptr, _  ' float (binary32)
    ByVal AnalogOut1  As Single Ptr  _  ' float (binary32)
    ) As Long
LJ_AOUpdate = DylibSymbol(LJ_lib, "AOUpdate")   ' Function Ptr
If LJ_AOUpdate = 0 Then
    Print "ERROR: 'AOUpdate' load failed!"
    Beep : Sleep : End 2
End If

'--------------------------------------
'Start of Scrolling Plot routine.

Screen 640,480                                                         ' Set VGA screen mode, 8 bit color.
Color 0, 0                                                                 ' Set up dark screen for scrolling plot.
CLS
FileNam = "TestFile.dat"  ' Just a test file name to write plotted data values.
LeftGraphCol = 20
GraphCol = LeftGraphCol + 1
Line (LeftGraphCol - 1,470) - (630,470),12                 ' Set out plot abcissa and ordinate.
Line (LeftGraphCol - 1,10) - (LeftGraphCol - 1,470),12

NumChan = 4                                                            ' To sample 4 A/D channels.
For I = 0 to NumChan - 1                                           ' Channels go from 0-3.
Locate I*14+8,1: Color 5-I,0                                      ' Color-code A/D Inputs 0-3.
Print "Ch": Print i                                                      ' Print A/D Channel labels on screen.
Next
If FileNam <> "" THEN                                               ' Print data file name on screen.
    LOCATE 60, 3: Color 7,0: Print " Recording to ";
    color 14,0: Print Filenam; " ";
EndIf
If Filenam <>"" Then OPEN Filenam for output as #1    ' Open the file for writing.

Locate 60,58:Color 7,0                                              ' Display the labels for Dig inputs and outputs on screen.
Print "O0:   O1:   I2:   I3:"

MaxScans = 1500                                                       ' Max # of scans of A/D inputs and I/O ports before auto-termination.
NumScans = 0                                                            ' In-loop counter for # of scans of A/D inputs and I/O ports.

Do                                                                            ' First acquire A/D inputs in array of size NumChannels (4 here).
Dim As Long     LJ_idnum = -1, _        ' use @LJ_id in call (pointer)
                LJ_demo = 0, _          ' straight use (not a pointer) real (not demo)
                LJ_stateIO(0 To 3), _   ' digital pin's: 0 .. 3 (lo = 0, hi > 0)
                LJ_updateIO = 0, _      ' default: don't update digital IO's (output)
                LJ_ledOn = -1, _         ' default: ON
                LJ_numChannels = 4, _   ' get 4 analog channels (max.)
                LJ_channels(0 To 7) = { 0, 1, 2, 3, 4, 5, 6, 7 }, _ ' SE channels (2 call's needed!)
                LJ_gains(0 To 3), _     ' not used on SE channels only differential channels
                LJ_disableCal = 0, _    ' typically: OFF
                LJ_overVoltage(0 To 7), _   ' per call only 4 needed
                LJ_idx = 0              ' helper for channels selection (0 or 4)
Dim As Single   LJ_voltages(0 to 7)     ' either @LJ_voltages(0) or @LJ_voltages(4)
If LJ_AISample(@LJ_idnum, LJ_demo, @LJ_stateIO(1), LJ_updateIO, LJ_ledOn, _
               LJ_numChannels, @LJ_channels(LJ_idx), @LJ_gains(0), LJ_disableCal, _
               @LJ_overVoltage(LJ_idx), @LJ_voltages(LJ_idx)) > 0 Then
    Print "ERROR: 'LJ_AISample' call failed!"
    Beep : Sleep : End
Else                                                                        ' Call not failing means successful sampling.
    NumScans = NumScans + 1                                   ' Increment # of scans of A/D and Dig I/O ports.
    Locate 59, 33: Color 7,0: Print "Scans:";: Color 14,0: Print Numscans;  ' Print NumScans on screen.
    Color 7,0: Print " of:";: Color 14,0: Print MaxScans;
End If

Dim as Long LJ_EIidnum          = -1, _                        ' To read Digital Ports IO2 and IO3.
            LJ_EIdemo           = 0,  _
            LJ_EIchannel        = 2,  _
            LJ_EIread           = 0,  _
            LJ_EIstate          = 0
If LJ_EIDigitalIn(@LJ_EIidnum, LJ_EIdemo, LJ_EIchannel, LJ_EIread, @LJ_EIstate) > 0 Then
    Print "ERROR: 'LJ_EDigitalInCh2' load failed!"
    Beep : Sleep : End
End If
EIState2 = LJ_EIState
LJ_EIChannel = 3
If LJ_EIDigitalIn(@LJ_EIidnum, LJ_EIdemo, LJ_EIchannel, LJ_EIread, @LJ_EIstate) > 0 Then
    Print "ERROR: 'LJ_EDigitalInCh3' load failed!"
    Beep : Sleep : End
End If
EIState3 = LJ_EIState

Dim As Long     LJ_EOidnum  = -1, _                           ' To write Digital ports IO0 and IO1
                LJ_EOdemo   = 0,  _
                LJ_EOchannel= 0,  _
                LJ_EOwriteD = 0,  _
                LJ_EOstate  = 0     
If GraphCol = 300 THEN                                              ' Just for giggles, at middle of plot set Dig Output IO0 to 0, IO1 to 1     
     LJ_EOChannel = 0
     LJ_EOstate  = 0     
     If LJ_EODigitalOut(@LJ_EOidnum, LJ_EOdemo, LJ_EOchannel, LJ_EOwriteD, LJ_EOstate) > 0 Then
        Print "ERROR: 'LJ_EODigitalOutCh0' call failed!": Beep 
        Else EOState0 = 0
     End If 
     LJ_EOChannel = 1
     LJ_EOstate  = 1
     If LJ_EODigitalOut(@LJ_EOidnum, LJ_EOdemo, LJ_EOchannel, LJ_EOwriteD, LJ_EOstate) > 0 Then
        Print "ERROR: 'LJ_EODigitalOutCh1' call failed!": Beep 
        Else EOState1 = 1
     End If 
End IF
If GraphCol = 21 THEN                                                'Just for giggles, switch IO ports at left of plot so Dig Output IO0 is 1, IO1 is 0                   
    LJ_EOChannel = 0
    LJ_EOstate  = 1     
    If LJ_EODigitalOut(@LJ_EOidnum, LJ_EOdemo, LJ_EOchannel, LJ_EOwriteD, LJ_EOstate) > 0 Then
        Print "ERROR: 'LJ_EODigitalOut3' call failed!": Beep
    Else EOState0 = 1
    EndIf
    LJ_EOChannel  = 1     
    LJ_EOstate  = 0     
    If LJ_EODigitalOut(@LJ_EOidnum, LJ_EOdemo, LJ_EOchannel, LJ_EOwriteD, LJ_EOstate) > 0 Then
        Print "ERROR: 'LJ_EODigitalOut3' call failed!": Beep
    Else EOState1 = 0
    EndIf
End If 

' Now graph Scrolling Plot.
Line (Graphcol+1, 461) - (GraphCol+1, 10), 0            ' Black line wipes across plot one step ahead of new data.
If Filenam <>"" THEN
    If NumScans = 1 Then                                          ' On first scan, write a file header describing data.
        Print #1, "  Time    Scan#   AD0    AD1    AD2    AD3  O0 O1 I2 I3"
    End If   
    Print #1, Time$;
    Print #1, Using "#######"; NumScans;
EndIf

For I = 0 To NumChan - 1
    Locate I*14+9,4: Color 5-I
    Print Using "+##.##";LJ_Voltages(I)                      ' Print A/D input voltages on screen and write them to data file.
    If FileNam <> "" THEN Print #1, Using "+##.###"; LJ_Voltages(I);   
    LJ_Plot (I) = LJ_Voltages(I) *275 - i*112 + 2          ' Gain/offset #'s are fudged for plot placement; will need changing for diff voltage ranges.
    VoltTemp =  LJ_Plot(I)
    If VoltTemp < 11 Then VoltTemp = 11                    ' Confine displayed points to plot area.
    If VoltTemp > 461 Then VoltTemp = 461
    line (Graphcol, VoltTemp) - (GraphCol, VoltTemp-2), i+2         ' Draw data points with height*2 for thickness.   
Next I

Color 14, 0
locate 59,61: Print Str(EOState0);                            ' Print Digital I/O values at bottom right of plot.
locate 59,67: Print Str(EOState1);
locate 59,73: Print Str(EIState2);
Locate 59,79: Print Str(EIState3);

If FileNam <> "" Then                                              ' Write Digital I/O values to data file.
    Print #1, Using "###"; EOState0;
    Print #1, Using "###"; EOState1;
    Print #1, Using "###"; EIState2;
    Print #1, Using "###"; EIState3
EndIf

GraphCol = GraphCol + 1: If GraphCol >629 then GraphCol = LeftGraphCol + 1        ' Plot at right end of abcissa; reset to plot left.

S = Inkey
Loop Until NumScans >= MaxScans or S = chr(27)      ' Keep scanning until MaxScans or Esc keypress.

Locate 57, 28                                                         ' Prompt on screen to end program.
Color 7,0: Print "Press <";
Color 12,0: Print "Enter";
Color 7,0: Print "> to End Program."

Do                                                                        ' <Enter> keypress to end proggie.
S= inkey   
Loop Until S = CHR(13)

Close #1                                                               ' Close data file and release loaded DLL.
DylibFree(LJ_lib)
End