Triggering led

[Nadjil]

I am new with LabView. I am working on project to control triggering of Led.

First I want to build a trigger mechanism for Led using LabView, then testing it if I can trigger my experiment.

Any suggestion or tips how to start or to build it?

[RedAG · Accepted solution]

This depends on the device you are involved with. Please post the devices you are working with.

Also, since you are a newbie, one advice is to spell LabVIEW correctly, a lot more people will take you seriously then.

[Nadjil]

Thank you for your reply and your advice.

First; I want make program with LabVIEW a controller to control a Led to trigger a PPU of MR. I want to control this Led, continuous or using a puls to trigger the Led. I am watching a lot of Lectures on LabVIEW but still need to learn a lot about it.

Is there a function that generate a puls or continuous signal in LabVIEW?

If I want to connect the Leb to the software what do I need? Can I use USB port or special device from NI?

Second; is there a function to save or recording the signal, then apply it agin? This part will come later in my project.

Kind regards,

Nadjil 

[RedAG]

http://zone.ni.com/devzone/cda/epd/p/id/1342 

The above link concerns a RT target and contains an example.

if you are using a microcontroller like Arduino, this link https://forums.ni.com/t5/LabVIEW-Interface-for-Arduino/Arduino-Example-Simple-LED/ta-p/3522414

There are many examples for continuous or Pulse generation. Look at the examples or try here for various examples for vi's https://www.ni.com/docs/en-US/bundle/labview-api-ref/page/menus/categories/signal-processing/ansigge...

There are number of ways to connect to a LED, such as USB or if you a hardware such as the PXI. However, if you just want to do this project, there is no point buying a PXI. 

If you are using USB, you need to install the appropriate driver for the concerned USB. 

The seconf part, you can deal with later once you have communication to the LED.

[Nadjil]

I will use the USB port first, I didn't do that before. What do I need to do it? Devices or material, I am really new with LabVIEW and working with these kind of projects.

[RedAG]

Nadjil,

Do you currently have any NI hardware?

Here are some devices https://www.ni.com/en/shop/data-acquisition.html

http://www.ni.com/usb/ 

Have a look through it too see if there is a device that you particularly want or is suited for your application. If you are not sure, the best way is to contact NI and ask them directly. They would recommend the best device based on your needs. Once you have the hardware in place, you should read upon how to control your hardware and then program. 

If then, you have specific problems, post here with your issues and some one will surely help you.

[Nadjil]

I looked to the links you have send me. I found something, but still now sure what is the best option for my project. I still have to talk to my supervisor to know what he want? What is going to be the final results?

I want to trigger 1 Led and receive 1 signal from Light gate, the signal I receive I record it and use it to trigger the Led again. I want to use the USB for that.

I found this product, what do you advice? It is a good choice or not? What is the alternative choice?

https://www.ni.com/en-us/shop/model/usb-6501.html

[NIquist]

This is a nice digital interface but it is software timed.  That means the top speed that you can toggle the outputs or read the inputs is a few milli-seconds and that will NOT be deterministic.  (It depends on what else your PC's CPU is doing at the time.)

If you just intend to flash an LED at a speed a human can see then it's fine but if you want to transmit information through Pulse Width Modulation (PWM) or anything of that nature, you'll need to look into a DAQ device that is hardware timed.

[RedAG]

NIquist makes a very good point.

You better clear it with your supervisor what exactly he wants you to do. First ask him if it is just for triggering an LED (which I think is the case since you are new to LabVIEW) or does he want to actually transmit/ interpret data or pulses based on the LED on/off phase (PWM).

If you just want to trigger, the device you suggested is OK. But, for you to acquire a lot of pulses you might want to look into something else.

Let us know once you have cleared it with your supervisor.

[Nadjil]

Thank you for your reply both of you.

Tomorrow I will have my meeting with the supervisor. I shall discuss everything with him.

My work is:

I have to send continuous signal to the Led(1) while someone (person) using a bicycle he/ she will trigger the device. The Led(1) will be part of Light gate that trigger the device. Next to that I have to use another Light gate this one will be connected to PC (LabVIEW) also. I have to recorded this signal when the person is cycling, then send it again to the Led(1) to trigger the device while the person not cycling.

This experiment contain:

Phase-1: Sending continuous signal to Led(1) and recording the pulses from Light gate (Led(2) and the receiver of Led(2))

Phase-2: Sending the sequence I recorded from Light gate to Led(1). The pulses I am going to send it could be everything I recorded or part of the signal I record or I might do some signal processing before send it. This will be discuss later. 

P.S.

Led(1) will trigger the device because Led(1) will be part of the device.

I hope this is more clear about what I am going to do. But I shall wait for the meeting with my supervisor.

Thank you in advance for your help.