Lights to help aim

[Electronica1]

Originally Posted by Michael Hill

I've been wondering...is there an advantage to using a flashlight rather than the LED ring? Is it just a cost/availability thing or is there some technical advantage as well? #KnowsNothingAboutCV

Who said anything about using the flashlight for vision processing?

[Michael Hill]

Originally Posted by Electronica1

Who said anything about using the flashlight for vision processing?

Is it used another way?

[Electronica1]

Originally Posted by Michael Hill

Is it used another way?

You set up the light so it is lined up with where you shot goes. Then for shooting all you have to do is line up the light with the high goal and fire. You get an easy way to line up your shot without having to use vision processing.

[Michael Hill]

Originally Posted by Electronica1

You set up the light so it is lined up with where you shot goes. Then for shooting all you have to do is line up the light with the high goal and fire. You get an easy way to line up your shot without having to use vision processing.

Then what's the point of the light? Drivers can see the goals with the camera already.

[Peyton Yeung]

Originally Posted by Michael Hill

Then what's the point of the light? Drivers can see the goals with the camera already.

We use ours like a laser sight on a gun. We don't use it with the camera at all.

[Travis Hoffman]

Originally Posted by Michael Hill

Then what's the point of the light? Drivers can see the goals with the camera already.

Often drivers don't like looking down away from the field....

[apm4242]

Originally Posted by Coach Seb

I bought the exact same thing that was recommended by apm4242....

- LED Flashlight with zoom
- DC-DC Voltage Converter/Regulator
- Spike Relay

I'll check the voltage again... last night we had 10V on the spike relay, i did not check the voltage after the converter yet as we assumed we fried the spike... but yet between test it worked... still wondering...

I tried sizing a resistor that would work for the Hausbell LED Flashlight but could not find the LED data sheet. I don't have the flashlight in front of me, so I couldn't try to pull a model number off of the LED. Going off of what CREE offers, I tried to find an LED using the flashlight specs (300lm, size, Q5, etc) and found a few LEDs with a forward voltages of between 2.9 V and 3.5 V and forward currents of 1000 mA for white light.

Using the equation R = (Vs - Vf)/i where Vs is supply voltage (3.3 V in my case), Vf is forward voltage, and i is current, gave resistor values between 0.4 Ohm and 0 Ohm. From what I have read and from how the math works out, you don't need a resistor if the supply voltage is less than the forward voltage and there are no voltage spikes (assuming the LED lights up at all).

I'm a little out of my wheelhouse with this stuff. Hopefully someone with a little more experience will come along and offer some wisdom...

Cree Components
Similar LED Data Sheet 1
Similar LED Data Sheet 2
LED Current Limiting Resistors Tutorial

[Ninjastahr]

Originally Posted by Peyton Yeung

We use ours like a laser sight on a gun. We don't use it with the camera at all.

Why not just use a beambreak sensor? They have the range for it* and would be able to tell you exactly when you are pointed at the goal, and are fairly easy to see.

*they are rated for use at that range, but I have never seen it done

[Peyton Yeung]

Originally Posted by Ninjastahr

Why not just use a beambreak sensor? They have the range for it* and would be able to tell you exactly when you are pointed at the goal, and are fairly easy to see.

*they are rated for use at that range, but I have never seen it done

We use ours for telling us where we are pointed at the goal. The goal doesn't have much room for horizontal misalignment so the flashlights shows us left to right where our shot will go. It seems to work well because we were typically shooting with an 85-90% accuracy.

[stoddard]

How do you wire a flashlight to the robot, this is our second year and there is still a lot of new stuff for us to learn?

[Ninjastahr]

Originally Posted by Peyton Yeung

We use ours for telling us where we are pointed at the goal. The goal doesn't have much room for horizontal misalignment so the flashlights shows us left to right where our shot will go. It seems to work well because we were typically shooting with an 85-90% accuracy.

Why not use a camera and a vertical line on the dashboard output?

[ahudson]

My team uses Labview and could use some assistance in setting up the use of LED lights to help aim. Our idea was to be able to determine when our robot was at the right distance from the castle wall to shoot. We have the LED mounted on our camera but are not able to set it up in Labview. IF you can help walk us through this, email me at ahudson@adairschools.org and I will forward it to our programmer and he can communicate with you better than I can.

[Darkseer54]

Originally Posted by Ninjastahr

Why not use a camera and a vertical line on the dashboard output?

Because that would involve the complexity of programming a camera and running some form of vision processing. Using a light involves wiring a flashlight to a spike, and programming that spike to turn on and off on command.

Driving wise, the difference is you are in full control of the robot at all times, whereas if you were using a camera you have to relieve your control of the robot to your control loop. For teams without a strong programming group (or even teams with a strong programming group who just prefer to avoid sensors) a flashlight is a much simpler way to align your shooter rather than going through the trouble of using a camera.

[Ninjastahr]

Originally Posted by Darkseer54

Because that would involve the complexity of programming a camera and running some form of vision processing. Using a light involves wiring a flashlight to a spike, and programming that spike to turn on and off on command.

Driving wise, the difference is you are in full control of the robot at all times, whereas if you were using a camera you have to relieve your control of the robot to your control loop. For teams without a strong programming group (or even teams with a strong programming group who just prefer to avoid sensors) a flashlight is a much simpler way to align your shooter rather than going through the trouble of using a camera.

No, I mean just looking at the camera to see the goal on the driver's station without processing the images. You can just have a set line of black pixels (using the NIVision.imaqDrawShapeOnImage() or imaqDrawLineOnImage()? in Java) in the center of the image, line it up manually with the center of the goal, and shoot the ball into the goal. It's really just as easy as setting up a spike.

[Ninjastahr]

Originally Posted by ahudson

My team uses Labview and could use some assistance in setting up the use of LED lights to help aim. Our idea was to be able to determine when our robot was at the right distance from the castle wall to shoot. We have the LED mounted on our camera but are not able to set it up in Labview. IF you can help walk us through this, email me at ahudson@adairschools.org and I will forward it to our programmer and he can communicate with you better than I can.

Are you having trouble using the LEDs themselves, or with getting the position of the goal using the camera?