Setting sampling rate for crossbow and vibration analysis using labview

[simplyedwin]

Hi people!

I am currently working on condition monitoring using crossbow wireless sensor motes. I have some inquiry which i needs help. They are as follow:

(1)

I am using the example given and did some amendment. I am getting vibration reading every second which means that i might have lost some information between 0 to 1 sec. Hence, i need to change the sampling rate. Is there any way that i can change via the VI like data points?

(2)

I encounter a very weird error code: 8001 every time I stop my application using the conditional terminal for the while loop. 

(3)

I am plotting my graph chart using  each element extracted out instead of the array of data from the data VI. Is it correct ?

(4)

Why is there 2D array used in the example? I am thinking is that since the packet is just an array so 1D array should be fine.

(5)

Lastly, how do i use spectral vi to monitor the frequency of the vibration which the mote sensed ? 

The attached file is my VI. 

Regards,

Edwin

Message Edited by simplyedwin on 03-06-2010 03:34 AM

[simplyedwin]

Hi there,

I have attached the wrong file before this message. The file attached here is the correct one. Btw, I have removed the health.vi as it is making my application to respond very slow, about 2 min per reading.

Regards,

Edwin 

Message Edited by simplyedwin on 03-06-2010 03:59 AM

[simplyedwin]

Hi there,

For the error code in the 1st message that i have posted, The following error message is what i received when i remove the new while loop or press the stop at the while loop conditional terminal: 

"Error 8001 occurred at Generic Read.vi

Possible reason(s):

Some or all of the samples were not available for some of the nodes specified"

Regards,

Edwin 

[Roop]

Hi,

I am also working on one such project. I am trying to change sampling rate of the node by using drivers VIs available. Though the program is not showing any error but the rate is also not updated.

In case you have found soluion o your problem ,pl le me known.

regards

Roop

[simplyedwin]

Hi Roop,

I have finished the project about a year ago. So i have forgotten most of the stuff. And I could not solve the sampling issue in the end. LOL!

Nonetheless, i did figure out in the end after some reading and helps from my friends, though the project was already finished. From what i know, you can't change much of the setting in the VIs to control the sampling rate. The only way that you could do that is to write a TinyOS program to make use of the EPPROM on the  crossbow mote so that you keep transfer more than 1 reading in a packet e.g. 8 readings in a packet. You can find the guides and tutorial on how to write a simple program to make use of the memory cell.

So once you are able to write the script, you will then need to figure out how to extract out and display those data. For this, I couldn't help you much as i didn't really try it out. But I believe experts at NI could help you out.

Anyway, hope that this response could give you a better direction in doing your project.

Good luck and take care Dude !

Regards,

Edwin

p.s: You need to love programming using nesC otherwise you won't get the sampling rate you want d^_^b ! 

[Roop]

Hi Edwin,

Thanks for the information.

I am aware of TinyOS program. On mote how to change sampling rate is clear to me.

I am interested to change rate from gateway node PC using Crossbow XWSN drivers for labVIEW (generic read.VI) , but the problem is drivers are not working.

If some one can provide information on the drivers for downsream communicaion , it will be of grate help.

Regards

Roop.

[Roop]

Hi Edwin,

Thanks for the information.

I am aware of TinyOS program. On mote how to change sampling rate is clear to me.

I am interested to change rate from gateway node PC using Crossbow XWSN drivers for labVIEW (generic read.VI) , but the problem is drivers are not working.

If some one can provide information on the drivers for downsream communicaion , it will be of grate help.

Regards

Roop.

[tjDude]

Hello @Roop,

Have you found the solution for updating refresh rate through LabVIEW?? I'm working on a similar project which requires me to transmit information from the Base Mote to the others in the WSN to change their LED states etc..

Any help will be grateful..

Thanks