pH probe>>pH stamp >>arduino>>LabView

[chup90]

Hi guys

I have constructed a pH meter using a pH stamp and Duemilanove arduino. I want to send those pH readings to Labview. it is in serial rite? I havent seen any pH interface in Labview. so how do i do this?

I have installed all the required arduino Labview interface toolkit and i even tried th simple LED example. i got that......But what do i do next???

[hrh1818]

Because the PH Stamp has a RS232 interface you can not use the LIFA tool kit with it.  See:

<http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Biometric/pHStampdatasheet341.pdf>

But what you can do is use your Duemilanove as a USB to RS232 converter and the serial interface capability of Labview to interface your Duemilanove to your PC.  I suggest you use the "Advanced Serial Write and Read.VI" that comes with Labview as a starting point for building a Labview program to work with your PH Stamp. 

There is one hidded gotcha.  When you iniially connect Labview to your Duemilanove it resets the Duemilanove and the Duemilanove for approximately 2 seconds ignors all commnds sent to it.  This mens afer you start your VI running you need to wait 2 seconds before yousend a command to the Duemilanove.

hrh1818

[chup90]

thanks man.

i got it working. but like u said i got some 1 or 2 second delay. my reading on the LCD is 2 second slower than on the labview. Is that normal? what should i do?

another thing is that, how do i change that interface into graph? can it be done?

http://imageshack.us/photo/my-images/812/advancedserialvisetting.jpg/

[hrh1818]

Yes, you can either add a chart or repalce the text box with a chart. Get a Waveform Chart from the following location.  Controls Palette > Modern > Graph > Waveform Chart and place it on your front panel.  You will also need a "fract/Exp - String to Number" block to convert an Ascii string to a double for use with the chart.

Get it here > Functions Palette > Programming > String > String/Number Conversions > fract/Exp - String to number

The 1 to 2 second LCD display delay you are seeing is different than what I was referring to.   I would need to see your swketch before I could trouble shoot that question.

hrh1818

[chup90]

I am just starting to use Labview. can i simply modify the VI file that i attached? so that i can put on the graphs and other stuff. Or is there any other simpler VI that i can work with?

sorry I dunno how to attach stuff, but here's the links

VI file : http://www.filedropper.com/202309

picture: http://www.filedropper.com/advancedserialvisettinganderrors

pH meter sketch: http://www.filedropper.com/phmetersketch

[hrh1818]

Atttached is a version of Advanced Serial Write and Read showing how easy it is to add a Waveform Chart.  So yes you can add other goodies to the Advanced Serial Write and Read.VI,  I will try to answer the question about he LCD display delay this weekend.

hrh1818