Here’s a drawing and calculation if you’re doing it with a series R for each LED:
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Okay, so that’s the resistors I need for this circuit?
I don’t see the numbers of LED in that last calculation, so that’s irrelevant for that circuit?
Trying to understand, thanks for your patience! 
Need help with your tracking dog, I got you covered 
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Yes, each resistor will be 499 Ohms. The other resistors are not relevant for what we’re going here. We already determined that the total current from the power supply is 280mA (14 * 20mA), so we just have to make sure that the power supply is up to the job. I think I recall you saying it was a pretty beefy supply, so it’s good.
Here’s the circuit analysis just to be totally clear. You probably already know this, but just in case…
We’ve got 12 Volts at the top of every sub circuit.
We know there’s about 2V across each LED.
That leaves 10 Volts to drop across the resistor.
Knowing the Voltage and current, we calculate an ideal R.
Then, calculate power dropped across the resistor. P= IV or P=I^2R
Look up a standard resistor value.
Normally, once you have the standard value, you’d go back and calculate the current using: I = V/R and confirm that the actual current will suit your needs. 499 Ohms is so close I didn’t bother.
One other thought, when you’re doing these types of calculations that rely on assumptions (in this case that we are going to drop 2V across the LED), when you go to a standard value resistor, you should chose the closest standard value above the ideal calculated value. This way the current will tend to be slightly lower and errors will occur toward a safe solution. Again 499 Ohms is so close, it doesn’t matter, in this case.
That’s cool, you train tracking dogs? I want to get another Yellow Lab – but just to be my buddy, not to do any tracking.
Edit: It would be helpful if you could post a drawing of your circuit. I’m making educated guesses at what you have, but until I see it…
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I’ll post a picture, but from what I can see your guess of my circuit is probably spot on, the only thing that I’ve thought of adding is a pre-made PWM to regulate the backlighting with a pot.
I work as a dog handler here in Sweden, I love Labs!
If I where you I’d try out tracking just for the fun of it, Labs are great at it aswell.
Avoid ‘trailing’ if you do tho, make sure it’s ‘tracking’, It’s one of the most rewarding things you can do with your dog if you ask me 
That has got to be an awesome job, working with dogs.
My old Lab passed away last September and it hurt me really bad. I was finally able to start to turn things around when I started thinking about how lucky I was to have been able to spend time with him. I spent a lot of time training him (just not tracking) and I think toward the end he had me trained quite well. 
I don’t even know what ‘trailing’ is, so I will probably be hitting you up for advise.
Still a little hesitant though.
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Best job I’ve had, love working with dogs.
Sorry too hear that mate, being a dogowner is brutal, but the good memories will always remain, each one is a individual that can’t be replace, but the lessons learned always make life better for the next one
The good thing about tracking is that you don’t have to go on courses or spend a lot of time on it, since Labs have it natural, you can just try it on a walk when they’re pups aswell. You can have someone close to them go in and hide like 50m in the woods on a pre-determind point, then you can just walk over their track and see if the dog starts it’s nose or not, if it doesn’t, no harm done, you would just need to ‘wake’ the dog in that department 
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I’ll try it for sure! We used to have our dog wait in the kitchen after dinner and I’d hide a few treats in the living room while he waited for me to say O.K. His job was to sniff out the treats. Fun for all involved!
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That’s a good and fun play, that gives them way more satifaction than physical labor, read long walks and running. Brain exercises are great for them, helps to train patience and focus aswell!
I do the same at home
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Hi…I looked into Raspberry Pi and see there are a few variants accessible at DigiKey and will arrange the most recent. From the video, I think I’ve sorted out what a resistor does… it must restrict the current so the pins don’t wear out. What’s more, I think if the resistors were on the opposite side of the LEDs, the LEDs would not get the current they have to sparkle. I additionally think there must be a type of match between the LED and resistor so the LED will sparkle appropriately. I would figure an Ohm rating <200 on the LED would consume it out and >200 would most likely shield it from sparkling. Since I can get a few sheets, I figure I will explore different avenues regarding this. I looked forward at the excess points in the exercise and am seeing this learning experience may be fairly charming.
Digikey is probably quite expensive to get raspberry pi!
It does not restrict the current so that the pins don’t wear out, though if current were high enough you would get a short and things would burn, but that is not wear. Resistors limit current, you’ve got that correct, but it’s to protect other electrical components, smooth out signals(filters, debounce, etc) and such. It also doesn’t matter if it’s in front or behind a LED as long as both components are in series, the voltage and current properties do change inverse compared to a series an parallel circuit though, but I think that’s something for later. I feel like you don’t quite understand the basic properties of an electrical circuit just yet.