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Topic: leds And resistors (Read 1 time) previous topic - next topic

Grumpy_Mike

But you should never turn off the power to a string of WS2812s when the data pin is connected up anyway or you will damage them.
Also you have been told before that you have to use a series resistor in the data line and a large capacitor across the supply, these should be on the diagram, as well as the power and ground connections to the nano.

Here is how to post an image image guide

TomGeorge

#16
Feb 04, 2018, 11:29 am Last Edit: Feb 04, 2018, 11:30 am by TomGeorge
Hi,
You need to connect your LED like this, and as @Grumpy-Mike has said remove the switch.


Tom.. :)
Everything runs on smoke, let the smoke out, it stops running....

GreyArea

First...TomGeorge....thank you.

Second;

But you should never turn off the power to a string of WS2812s when the data pin is connected up anyway or you will damage them.
Also you have been told before that you have to use a series resistor in the data line and a large capacitor across the supply, these should be on the diagram, as well as the power and ground connections to the nano.

Here is how to post an image image guide
Have a look at thread here

https://forum.arduino.cc/index.php?topic=524448.0

Conveniently, it contains all of;

1. a suggestion to use imagebin
2. The reason I'm using imagebin
3. Two requests for the details on power surge protection, specifically resistors and capacitors.

The last one was never answered...maybe, just maybe because some people are too busy looking for everything that's wrong with a post rather than making ANY attempt to be helpful.

I'm new. Telling me I need a resistor and a capacitor doesn't help. I barely know what they do, but I'm vaguely aware they have different sizes.

Tom, again, thank you. Mike while I recognise your vast technical experience, it's no use to me if you can't deliver it without making me sit up and do tricks. I think it's best you just ignore my posts, I won't be offended.

GreyArea

Apologies to slipstick, also, thank you for the explanation.

Also apologies to Mike, seriously. Maybe it's just that too many of your 54,000 posts have been to idiots like me and that Tom and slipstick just haven't had their fill yet.

But the request stands...just ignore my posts eh? There are enough people on the forum who'll tell me what I've missed out without you.

I assume if I take power from the Arduino +5v and GND pins the risk to the LEDs is removed? Again, this is my newness showing. I'm a chemist by training and for me if someone gave me two five gram bags of something I'd assume that 5g = 5g. I naively thought it would be the same with volts.

groundFungus

#19
Feb 04, 2018, 02:46 pm Last Edit: Feb 04, 2018, 03:04 pm by groundFungus
Quote
I assume if I take power from the Arduino +5v and GND pins the risk to the LEDs is removed?
What makes you assume that?  What risk are you trying to mitigate?  How is the Arduino powered?

tinman13kup

Quote
I'm a chemist by training and for me if someone gave me two five gram bags of something I'd assume that 5g = 5g. I naively thought it would be the same with volts.
If you want to use that analogy then you must also figure amps as volume. If your bags are sized for 5g of Pb, surely you cannot fit 5g of feathers in it.
Tom
It's not a hobby if you're not having fun doing it. Step back and breathe

wilfredmedlin

#21
Feb 04, 2018, 02:56 pm Last Edit: Feb 04, 2018, 02:57 pm by wilfredmedlin
If your bags are sized for 5g of Pb, surely you cannot fit 5g of feathers in it.
Depends....



Keep Calm and call 0118 999 88199 9119725...... 3

Grumpy_Mike

#22
Feb 04, 2018, 03:53 pm Last Edit: Feb 04, 2018, 03:55 pm by Grumpy_Mike
Quote
Have a look at thread here

https://forum.arduino.cc/index.php?topic=524448.0

Conveniently, it contains all of;

1. a suggestion to use imagebin
2. The reason I'm using imagebin
3. Two requests for the details on power surge protection, specifically resistors and capacitors.
Looked at that that thread, so you think the advice from one member overrides the rules of How to use this forum. Pasting you images as attachment keeps everything in house and no one has to venture off into potentially malware ridden sites.

Power surge protection means something on mains supplies but very little about the sort of things we are dealing with here which is probably why no one received an answer.

It is not being pedantic it is helping you get the best answer but you seem to be hell bent on wasting peoples time here. I did see your initial post before you had any answers and refrained from kicking off the twenty questions quiz because I know you have a negitave attitude towards me. So when I saw something I could comment on sensibly this morning I decided to. Looks like I only antagonized you even more.

Point is if you are told something on one thread about using a data resistor and capacitor on those LED strips and then ignore it in later posts, it shows you are not up to the correct level to be attempting what you are doing and are only being a troll and total waste of space. You need to do more tutorials, examples and background reading. What you are doing is like someone asking about the nuances of Latin grammar when you don't even know what the words mean.  

I will leave it up to others to tell you what you are doing is stupid and not bother answering your posts again because you seem to resent me telling you what you have done wrong. From personal messages from other members I know I am not the only one who you have pissed off in your 111 posts here. So goodbye.

GreyArea

What makes you assume that?  What risk are you trying to mitigate?  How is the Arduino powered?
First two questions;


If you have wired it up like that it is a great way to damage your WS2812 LEDs. This is because the data signal from the Arduino will be much higher than the supply applied to the WS2812s
I inferred that this meant it was the separating of the power supply that caused the problem. The risk is explicitly stated by Mike "great way to damage your WS2812 LEDs"

The Arduino when I'm testin with this setup is powered through the USB by a portable mobile phone charger.

GreyArea

#24
Feb 05, 2018, 10:42 am Last Edit: Feb 05, 2018, 10:49 am by GreyArea
Still trying to get some info on the size of both capacitor and resistor required for use with the Arduino.

As my knowledge is so small, every time I try and add more info I just seem to confuse things, so assume I know nothing and you won't be far wrong. With that in mind;

1. Why do I need a capacitor?
2. What size do I need? Does it depend on the project? If so it's a pro Trinket controlling between 45-60 WS 2812b LEDs (the 8-led circuit is just a test rig)
3. Where does the capacitor go? (Detailed please, I've become aware that I misinterpret things like "in-line" etc

Same three questions apply to the resistor requirement.

The circuit is basically the same as my terrible diagram, but without the indicative "normal" LED and resistor and obviously more LEDs. In practice the power supply will be a 5v portable phone charger. I've been using one for over two months and it hasn't caused me any problems yet...it's impossible that all the LEDs will be on and with all three RGB channels powered at the same time due to the software running on the Arduino. This isn't a sustained lighting source, the LEDs flash on for a few seconds (less even) with a much longer (up to 10 seconds) intervening period of darkness, so the maximum power drawn isn't as high as the approx 18w with a 3.6A maximum that powering them all would require (source of calculation https://www.audectra.com/guides/power-consumption-of-rgb-led-strips/).

GreyArea

Also, can someone recommend an image size reduction app for an iPad?

TomGeorge

Hi,
Is there a graphics app on the smarty phone?
Check what it can do..

Tom... :)
Everything runs on smoke, let the smoke out, it stops running....

groundFungus

#27
Feb 05, 2018, 11:56 am Last Edit: Feb 05, 2018, 12:01 pm by groundFungus
I refer you to the Adafruit guide for cap size, resistor size and wiring details.




GreyArea

I refer you to the Adafruit guide for cap size, resistor size and wiring details.




Thank you!

GreyArea

Hi,
Is there a graphics app on the smarty phone?
Check what it can do..

Tom... :)
Everything apart from reducing size as far as I can see...

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