Labview Drivers for Wireless Sensor Networks

[David_Pratt]

Hey Milky,

It would be easier to determine the scaled differences if both the Mote data and xls spreadsheet were taken at the same time so we have concurrent data for the same reading.

[MiLKy83]

David,

Attached is the data taken with both Moteview and Labview just now. I coudn't run both at the same time, so I run it concurrently. Looks like my humidity data is inaccurate as well. Please help...

Kim

[RavensFan]

Any chance you are losing a byte of information in your data?  Or the parsing routines are not aligning correctly on the data you are getting?  I don't have your subVI's to be able to look in them.

Your raw text data looks pretty consistent.  The .xls file sometimes shows data close to your raw data, but sometimes is way off, such as oddly negative temperature data.  That makes me think a byte is mismatched or missing in your data stream, and the conversion of the raw data stream to numeric values might have problems.

Any time it seems like your light column in Excel is only in the 10's instead of the 100's, the other data in the row after that seems to be odd as well.

Also, are you sure your headers match up with your data in the Excel spreadsheet?  In Excel, you have Intersema temperature as around 1003, but that is the pressure in your text file which makes more sense for mbar.

PS.  Concurrently means the same as simultaneously, ie. the same time.

Message Edited by Ravens Fan on 03-04-2009 11:46 PM

[MiLKy83]

Sorry David and Ravens... the previous xls file was labeled wrongly. I've attached the corrected one with correct header (Intersema pressure suppose to be intersema temperature and X-axis suppose to be Y Axis). I couldn't take the data at the same time but I take the data from Labview  then Moteview then Labview... one after another. I've added data collected just now in the afternoon. I have attached my VI file as well for you guys to have a look.

Please help me to make the readings correctly scaled in Labview.

[David_Pratt]

Will MoteView's manufacturer give you the algorithms used in their code to convert the raw data on the sensors to their engineering units?

[MiLKy83]

Hi David,

I have attached the Xserve manual provided by Crossbow. I was told that all the conversion from raw data to engineering units is used in Xserve. Appendix C shows the conversions of raw data to engineering unit used in Xserve. How can this help in correcting my LabView reading?

Please help.

Kim

[MiLKy83]

Hi David and all,

I still couldn't solve the problem that I posted earlier.  I tried to add delay as attached in the xls file and the results that I observed are as attached in the seperate sheets in Book1.xls. Does anyone know how to get all data within range? Please advice...

[David_Pratt]

Hey milky,

I found some discrepancies in the provided raw data formulas from the Crossbow document and the formulas being used in the Parse MDA400 subVI.  For example the Humidity calculation in the CrossBow manual multiplies by .00008 and the subVI uses .000008.  Other numeric differences were present but the only way to verify this is what's causing your scaling issue would be to make the formulas match by fixing them and then running your program to see what values come out.

[MiLKy83]

Hi David,

How can this be done? Can u pls show me an example?

[David_Pratt]

Open up the CrossBow document and look at the formula for Humidity.  Double-click on the MDA Parse.vi in your code and look in the top text node where that formula is defined. Verify the formulas match and then save everything.  I can't show you or do it for you, you'll have to figure it out.