smart automated window blind

[hafiz]

Dear forumers,

Good day,


i have problems on developing my project research. Is it possible to use labview for the project. Below are the project details.

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The title of my project is to develop a PC-based smart room using labview.
These are my details and my current findings of my projects.

The objective of the project is to build an automated window blind.Basically, the blind will be connected with 24VDC motor. This is to rotate the blind slat angle. Next the slat angle will only operated when there is signals from LDR/ Lux Meter. The amount of light in the room will control the angle of the blind slat.

The purpose of this project is to give a comfort in a room and conducive for doing work.

The idea used in the project is by:
using H-bridge DC motor controller as controlling the rotation( forward/reverse) of the motor.
lux meter.Basically is LDR which calculate amount of resistance and will be converted to voltage and connected as input of DAQ
DAQ NI-USB-6009
several comparator such as op-amp connected parallel to control the resistivity of the lux meter and give signals to motor.

[Jochen]

Hi hafiz,

this sounds like a nice project and it's absolutely doable with LabVIEW. Still I have to give you the same answer as I did in many cases in this forum before: The USB-6009 is definitely the least fitting NI product for motion control applications. I think you have seen some of my posts about this topic (e. g. here), so I don't have to repeat the reasons for that statement.

As the ambient light typically doesn't change at high rates, your requirements in terms of communication speed to your motion controller are probably very low, so I don't recommend an NI motion control product in your case, as these are high performance devices, which are probabyl oversized for your application. For applications with low performance requirements, you can use an external controller with integrated drive and RS232 or USB interface. There are a lot of low cost controllers/drives like that available in the market. Ideally the controller comes with a LabVIEW instrument driver, but if you can't find a driver for the controller/drive under the linked address, you still could ask the vendor, if something is available. In case of an RS232 interface, it's also not very hard to program the communication by yourself.

Kind regards,

Jochen Klier

National Instruments 

[hafiz]

hi Jochen

thank you for the explanations.i have noticed that the usb6009 could only generate control signals (+/- 10 V). I have only been prepared with Labview 7.1, NI USB 6009, n daqmx driver (correct me if im wrong) for my project. Is it possible to continue with the given items?. Is it possible if i have step down my DC motor from 24v to <10v.

By the way, I have ask for help with  

 
Virtual Instruments Sdn Bhd (a National Instruments Company)
Wisma Kemajuan Jalan 19/1
Suite L 2-1, Level 2 46300 Petaling Jaya
Selangor, Malaysia

 and i have also received feedback from the sales engineer. She has gave me the engineer contact email but it doesn't help me much. i hope theres someone who can actually help on my project much like to supervise me?. Correct my approach if i was wrong again. Best regard.

[Jochen]

hafiz,

you can't connect a motor directly to the USB-6009 and if you connect a drive that accepts +/- 10 V control signals, the USB-6009 is the wrong device for your application. The USB-6009 is a low cost measurement device and it can't be used for deterministic control applications like motion control. Please follow the advice that I gave you in my last post.

Thanks,

Jochen

[hafiz]

thnx jochen.

by the way, i will be using a step down transformer 24V to <10V before applying to the input of the card. So this will enable the usage of the card right?

[Jochen]

hafiz,

this is my last answer to this thread and it's a chrystal clear NO:

NO, the USB-6009 is NOT a deterministic control device. You need deterministic control for motion control. DON'T use USB DAQ devices and especially not the USB-6009 for motion control! There is a very high probabilty for failure or very poor results.

Jochen

Message Edited by Jochen on 09-14-2009 10:58 PM