Lights to help aim
 

I have seen several teams using a light to help them aim when taking a shot. Could anyone recommend a light to use and any tips to using a light.

Re: Lights to help aim
 

Most people are using LED rings from here: https://www.superbrightleds.com/

I have seen them advertised as both "halo" and "accent" lights.

Re: Lights to help aim
 

we use a Maglite® ML100™ LED Flashlight Black

Re: Lights to help aim
 

Is the maglite a focused beam of light because we are looking for a light that is focused so we can hit shot from the back of courtyard.

Re: Lights to help aim
 

Take a look for yourself:
https://www.youtube.com/watch?v=nhmnSkCYeLk

Re: Lights to help aim
 

Although we're not using the system this year, we used an LED alignment system in 2014. Feel free to PM me or Billbo911 if you want to learn about how we set it up.

Re: Lights to help aim
 

Are you using the two-cell or three-cell version? Did you have to use a voltage regulator to drop the voltage to 3 V or 4.5 V?

Re: Lights to help aim
 

973 was very effective with a focused flashlight for aiming. They just lined up made the light reflect off the chains and boom in. Wish we thought of that rather than wasting time on auto-aim with LED

Re: Lights to help aim
 

Fair warning, our team used a flashlight to aim our shot with incredible success throughout all of our qualifications matches, however, in Eliminations, our opponents said that our flashlight was distracting/blinding them during the match. We were forced to unplug the flashlight, significantly dropping our accuracy. Be careful about relying on a flashlight to aim, I highly recommend you have some sort of fallback solution.

Re: Lights to help aim
 

Controlling your light via a relay should avoid this complaint. I've seen several teams (oursleves included) that turn their light on as part of their firing sequence. We tend to already be turned towards the tower by then, so we don't shine in anyone's eyes.

Re: Lights to help aim
 

Did your light have a lens to focus or was it just a light?

Re: Lights to help aim
 

Does anyone referee the validity of the claims of distraction from opposing teams? You definitely don't want to legitimately distract people with bright lights, but at the same time, I could see saying "hey, that's distracting! make them disable it!" as a way to gain strategic advantage.

Re: Lights to help aim
 

We have the same head referee at Tech Valley that we did at Pittsburgh, so if he suddenly disallowed our flashlight at Tech Valley because of some team's bogus claims, that would be a fun discussion indeed.

Did you leave your light on all the time or turn it on only when the shooter was on? Is your flashlight very large/bright?

We used China's finest Cree LED $6 specials from amazon.com. Cheap, light, bright, effective. And not overpoweringly so. I remember seeing the light sweep through the opposing driver stations at Pittsburgh on the way to aiming, but the hardy Ohio and Western PA types must have less sensitive eyes than those in New York City, cuz no complaints were lodged.

I remember 25's ridiculously large and bright lightzooka from 2012 being on all the time. I was standing behind the driver's glass watching matches at CMP and I remember the thing practically blinding me. I'm fairly sure it could induce migraines in people. I don't believe anyone asked for that to be turned off.

If you are pointing the light at the opposing drivers for an extended period in an attempt to intentionally distract them, that's one thing. If you are merely using the light for its intended purpose of aiming and shooting, that should be TOTALLY acceptable by ANY head referee. Running the light off a relay will certainly help matters.

If this becomes a thing, you can rest assured I will wage war against all those annoyingly bright green LED rings that are on 24/7/365 during a match. Those are CLEARLY meant to distract and annoy, right? They don't serve any other useful purpose in a match, do they? [/sarcasm]

#teamflashlight #allyourvisionledbelongtous

Re: Lights to help aim
 

That is absolutely absurd those bright green led rings are and have always been crucial structural elements on a robot.

Re: Lights to help aim
 

What height was the beam at? I could maybe see their point if it was pointed at eye level. We aimed our beam to hit the very top of the tower, but that was more out of convenience for mounting than anything else.

-Mike

Re: Lights to help aim
 

The keystone of any rock solid robot frame is welded-on Green LED rings, to be sure.

Re: Lights to help aim
 

@jijiglobe what flashlight were y'all using at NYC?

Re: Lights to help aim
 

We were never asked to turn off our light in 2012 because we did so ourselves. It was only ever turned on for a few seconds at a time while lining up the shot.

Re: Lights to help aim
 

OK then, exactly what we do this year. Precedent established. Use a relay. It's more than those vision teams usually bother to do. ;)

#teamflashlight

Re: Lights to help aim
 

We are using the 2 C-cell version. We use a https://www.pololu.com/product/2110 to give us 3.3V at 3.5 amps. IT works like a charm. The one downside is that the switch defaults to the off position. A Relay will not work so it has to be on for the entire match. You have to manually turn it on before each match. We are looking at alternate solutions.

Re: Lights to help aim
 

Ours ran on a single AA with the positive end facing into the flashlight. We made an acetal battery facsimile with a brass screw at the positive end. Wrapped the red wire around it and ran it up a groove milled into the side of the acetal. We then soldered a black wire to the case of the flashlight. The switch was in the rear end cap of the light, which was discarded. This light does have blink and strobe functions I think, but I believe they need to be triggered by repeated presses of the switch. If you leave the flashlight off long enough - something like a few seconds - it always reverts to turning it solid on when you apply voltage again.

I was really surprised to get the visibility and focus I got out of this little flashlight, which is roughly one inch in diameter and about 4 inches long.

Re: Lights to help aim
 

Thanks for the info.

It looks like you should be able to connect the EN pin to a DIO pin on the RoboRio to turn it on and off. You would have to remove the 100kOhm resistor on the D15V35F5S3 if you are using an input (VIN) higher than 5 Volts. This would require that the RoboRio be able to set the EN pin in the High state or Low state 100% of the time. I would expect the software should allow this but I am not sure since I take care of the electrical and mechanical aspects of the robot.

Re: Lights to help aim
 

Since a lot of people have been asking, I'm going to clarify that there was most likely an issue with our flashlight blinding drivers. I would never accuse them of lying about that. We were not the only team that was forced to unplug their flashlight though. After we received the complaint, the head ref asked all teams to shut down their flashlights.

For our second event, we will be working on ways to avoid the flashlight issue(such as pointing the beam at the bottom of the tower so it can't get people's eyes, as well as adding a dimming capability.

As for the people asking which light we used, we used a pocket flashlight that one of our team members bought at a hardware store, I don't remember what the part number was exactly, but it was about 6" long before we chopped off the battery compartment.

Re: Lights to help aim
 

As a team using vision quite heavily, this concerns me. We only turn on the lights to grab a single frame to identify the target but a blanket ban on lighting would negatively impact how we operate.

Now that a precedent has been established - do we need to ask a Q&A to expand on what defines "distracting" and what criteria must be met for those of us who want to use vision processing.

-s

Re: Lights to help aim
 

Fixed :D

But really, you guys were really bright at SWVA. Definitely lit up the tape.

Re: Lights to help aim
 

To clarify, we also had a camera with an LED ring, however, due to issues with FMS blocking our connection to our tegra, we were not using it for anything. They did not make us unplug the LED ring, just the flashlight.

Re: Lights to help aim
 

Any guidance on using the Cree flashlight would be totally awesome... we do have a spike relay.... assuming that would be connected on the Relay port on the RIO and then a voltage regulator between the Spike and the light to get me to the right voltage should do right ? Any picture would be appreciated.

Re: Lights to help aim
 

4242 used a setup like this at the CHS Greater DC District event with great success. Not only did it provide a bright focused beam for aiming at the low goal (we're a low goal shooter), but more importantly, it was actually bright enough to shine through the Sally Port and Drawbridge "wood" decals. Our driver was able to use it to square up to the defense without seeing the robot.

We used the following:
- LED Flashlight with zoom
- DC-DC Voltage Converter/Regulator
- Spike Relay

The LED flashlight had internal circuitry that allowed for 3 modes (high, low, flash). We only wanted the high setting so we took the circuit board out and wired the LED board directly to the voltage converter. This made wiring much easier as the LED board fit cleanly back inside the original housing. More conveniently, we used the metal clip on this flashlight as a mounting bracket by reversing it and drilling out the hole a bit. Next, we locked the flashlight in the zoomed position using a zip tie. Finally, we used a bunch of hot glue to secure the wires inside the area where the battery would go.

So, the full setup is how you described - Power Distribution Board > Spike Relay (with pwm wire connected to the Relay port on the RoboRIO) > Voltage Converter > Flashlight. FYI - We soldered all connections but lost power connection somewhere in our semifinal match during a BIG collision. We're still not sure what happened but we know it's the power because the relay still responds to the driver's commands.

Sorry I don't have any photos because the robot is currently bagged up. I can also provide screen shots of our labview code if anyone's interested.

Re: Lights to help aim
 

Thank you very much !!!! and yes LV screen shot would be totally awesome !

Thanks a bunch !

Re: Lights to help aim
 

Team TRx 145 would love to see screen shots of the LabView code!!!!

Thanks

Re: Lights to help aim
 

I don't have the code with me right now but I'll post screen shots later tonight.

If you can't wait, it's very similar to Team 358's Labview examples except ours uses a button toggle with "Off" and "Forward" as relay inputs. Don't forget to initialize in Begin.vi and end in Finish.vi.

Team 358's site seems to be down for the moment but Mark McLeod posted a .doc file with everything in it - http://www.chiefdelphi.com/forums/at...1&d=1454513427

Re: Lights to help aim
 

See attached for LabView screen shots. A few notes -

Wiring the blue relay values to the selector was tricky. If someone knows a better way, feel free to correct this but here's what I did - right click on Relay Set and create a constant. Sever the connection between the new constant and the Relay Set. Connect the new constant to the Select and then wire the Select output to the Relay Set. Now the Select will accept and return blue values.

Selecting "On" and "Off" as the relay values did not work - the flashlight just quickly flashed and stayed off. We had to set it to "Forward" and "Off".

The Relay vi's are in the WPI Robotics Library > Actuators > Relay area.

The feedback nodes are finicky. Sometimes they don't turn green when wired to a Boolean on the first try and the arrows may need to be switched (right click). The button toggle code is straight out of Team 358's guide. I highly recommend it. It's the best.

Re: Lights to help aim
 

At my first attempt, the light was very bright and it look awesome. Then as soon as i remove power and re-apply the voltage, then it was very dimmed....

I figure i burn the LED or something like that so i proceeed to wire LED flashlight #2, and exactly same thing happen... at first it was bright and just like i want it, then, remove the voltage to the LED and reconnect and it turn on but was very light....

?Is there a cycle to reset or something weird I have to do?

Re: Lights to help aim
 

Did you remove the round circuit board inside the flashlight? When functioning normally, there are 3 modes - high, low, flash. When you press the on/off button down half way, the mode switches and it remembers your last mode setting. The circuit board controls this function. It sounds like you might be simulating this by removing and reapplying the voltage.

Re: Lights to help aim
 

Yes, we removed the circuit board and solder the LED directly to the voltage converter.

Anybody experience this?

Re: Lights to help aim
 

Strange. We didn't see this. What flashlight and voltage converter are you using? Can you trace the source of the voltage drop with a multimeter to see if it's in the LED, relay, or spike? In other words, try checking if the LED is getting whatever the converter is supposed to put out

Re: Lights to help aim
 

Is the use of a laser pointer allowed on the robot? I feel like a laser would be exceedingly helpful for aiming and such.

Re: Lights to help aim
 

No. Typically, visible lasers are of Class II/III. The blue box on R9 says that you can only use Class I lasers.

Re: Lights to help aim
 

I don't know what kind of flashlight you started with. If it's a typical LED, then you have probably fried it by letting it have too much current. You need to have a resistor in series with it to set the current to a level where the LED will work properly.

Re: Lights to help aim
 

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...

Re: Lights to help aim
 

I need to do more than a cursory look at electronics for legality, but is it possible to run two flashlights off of one spike relay? We'd like to run one flashlight off of the positive signal and a different flashlight off of the negative signal. Our electronics team has an idea of how it may work, but nothing concrete until they're back from Spring Break.

Re: Lights to help aim
 

I was under the impression that the voltage converter made the resistor unnecessary. Not using the resistor worked for us. For reference, this is what Alan is talking about - https://www.sparkfun.com/tutorials/219

Re: Lights to help aim
 

That will work fine. Use the Spike's M+ terminal as the "plus" for one flashlight, the M- terminal as the "plus" for the other, and connect the "minus" of both flashlights to the V- terminal where the ground wire is coming from the PDP. You'll need to know that setting the Spike FORWARD will turn on one light, setting it REVERSE will turn on the other, and setting it ON will turn them both on. OFF will of course turn them both off.

It used to be normal to run two pneumatic solenoid valves from one Spike in exactly this way.

Re: Lights to help aim
 

Honestly, I would use a SuperBright LED ring. You just put it around the camera, and you can HSL/HSV Threshold the image to find the goal. Our team has used this technique and I know for a fact that it works, and doesn't *quite* blind people. Though, it does come close sometimes...

Re: Lights to help aim
 

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

Re: Lights to help aim
 

Who said anything about using the flashlight for vision processing?

Re: Lights to help aim
 

Is it used another way?

Re: Lights to help aim
 

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.

Re: Lights to help aim
 

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

Re: Lights to help aim
 

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

Re: Lights to help aim
 

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

Re: Lights to help aim
 

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

Re: Lights to help aim
 

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

Re: Lights to help aim
 

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.

Re: Lights to help aim
 

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?

Re: Lights to help aim
 

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

Re: Lights to help aim
 

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.

Re: Lights to help aim
 

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.

Re: Lights to help aim
 

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.

Re: Lights to help aim
 

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

Re: Lights to help aim
 

As stated above, most drivers don't like looking down at the driver station. So either you'd need some form of HUD so that the driver can look at the robot and view the camera at the same time, OR simply use a flashlight to shine onto the goal to show that the robot is aligned or not. Also, any lag in the camera image showing on the dashboard will affect your accuracy. Both can be viable ways of doing it.

Re: Lights to help aim
 

That would require the drivers to take their eyes off the robot.

Re: Lights to help aim
 

First, the camera image is not always immediate. If you try to steer your robot by looking at the screen, you're very likely to overshoot the target direction while you try to line things up. Second, it's just a whole lot easier to not have to look at the laptop screen in order to aim your robot.

Basically, a moving spot of light on the actual tower, where the driver is already focusing his or her attention, is much simpler to deal with than a flat and slightly delayed image of the tower on the laptop.

Re: Lights to help aim
 

Did someone order cheesecake?

What you will need for just the flashlight.
A 12 volt flashlight
A spike relay.
To augment the flashlight so it has a more focused beam or less light showing overall you can use
Black electrical tape
A focusing lens (a lot of science departments at schools have these for various experiments)




We use this 12 volt flashlight wired to a spike relay. This flashlight is nice because it is one where the light can pivot and it really helps that we don't need to angle the entire thing in order to aim it properly. Earlier in the build season I also borrowed a focusing lens from the physics department at the school I mentor with (most science departments at schools do an occasional light activity and should have one otherwise they can be purchased through a ) and after measuring the optimal distance for placement of the lens had a student cad and 3D print something for a smaller flashlight to hold the lens at the correct distance. We reused that mount with zip ties and tape instead of cading a new one for the flashlight I posted above due to time constraints. Since the lens we have is smaller then the flashlight we used black electrical tape to reduce the amount of light that shines through hopefully reducing the chance of it being distracting. Wiring the flashlight was simple because it is done through the spike to the battery leads which gives you the ability to turn them on and off.

With the exception of the 3D printed mount (which in all fairness you can use any sort of material to mount the lens to the flashlight) everything is all COTS and takes minimum work to put together.

Cheese it up!

Re: Lights to help aim
 

I am guessing there is some reason that you can't simply use a motor controller outputting 3 Volts? I would assume this was the simplest way to power a 3V light, but the fact that no one has suggested it makes me think it wouldn't work.

Re: Lights to help aim
 

The reason you can't use a motor controller outputting 3 volts is simple: You can't get an FRC legal motor controller to output 3 volts. It's either providing no voltage or full battery voltage (in one direction or the other). Inductive loads like a motor will average out the pulse-width modulated battery voltage, but a 3 volt flashlight is likely to be very unhappy with even a brief application of four times the expected voltage.

Re: Lights to help aim
 

Hi Mike i'm Cody i was wondering how you guys mounted the flashlight? I would like to hear how you guys did it. Please reply asap. Thank You.

Re: Lights to help aim
 

Hi Mike i'm Cody i was wondering how you guys mounted the flashlight? I would like to hear how you guys did it. Please reply asap. Thank You.

Re: Lights to help aim
 

Might be better to PM him if you need a response from him specifically.