Questions tagged [rgb]

Short for: Red Green Blue. The primary colors in light. Mix them to create any imaginable visible color of light. Questions are typical in reference to RGB Leds, RGB Led drivers, and code related to mixing RGB light, but can include RGB Video Standard in VGA monitors.

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High Power RGB Led control

We have got a 20W led ,RGB from a good seller in China. I have a few questions regarding the led (see the attached image) Is there a data sheet to this Leds? something generic ? How can you know ...
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2answers
3k views

how to get the RGB value of a color using phototransistor or photodiode?

I'm making a color analyzer which can measure Red, Green, and Blue portions of a color (ex: 128,255,0).I'm not supposed to use pre-made color sensors and need 1% ACCURACY. I used three LEDs - R,B &...
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2answers
969 views

Arduino - Controlling 8 RGB LEDs (beginner question)

First time poster here. I have an Arduino Uno project that will require 8 RGB LEDs to be controlled. They will be turned on and off with pushbuttons, cycling through red, then green, then blue, then ...
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10k views

Why does a resistor in my Neopixel data line work at all?

Adafruit's best practices for their Neopixel LED strings say, "Place a 300 to 500 Ohm resistor between the Arduino data output pin and the input to the first NeoPixel." Someone asked about the ...
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1answer
2k views

WS 2811 lights flickering

I'm working on a project involving a bunch of daisy-chained WS2811 lights and I'm noticing significant flickering on the ones at the end (lights #16-30 in a chain of 30). Right now, the circuit is a ...
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1answer
1k views

how to measure RBG values of a color using phototransistor

I am developing a circuit which can measure RGB values of a given color. I have used LED to transmit light and reflected light is filtered by 3 R, G, B filter papers. Earlier I used LDR and found that ...
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1answer
678 views

Use 4-pin S-video cable connector on RGB LED?

I'm hoping to make some 4-pin RGB LEDs (R, G, B, GND) easily hot pluggable, so I'm wondering if 4-pin S-video connectors could be used. Now, 2 of the pins on a S-video connector are GND, so would ...
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2answers
669 views

LM317 and PWM grounds

I have a question regarding the LM317 and PWM. My circuit receives +12v and has three grounds (R,G,B) that are PWM. I need to drop the voltage down to 3.2 volts from the 12 volt source. NOTE: I know ...
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1k views

10 3W RGB LEDs in series control current

I'm having the following schematics connected to a 5V 25A DC power supply. All LEDs are 3W RGB, additional values are. R1: 6.8 ohms 1/2W R2: 4,7 ohms 1/2W R3: 4,7 ohms 1/2W I'm using an Arduino Mini ...
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2answers
8k views

LDR + RGB Led = Color sensor. How to calibrate it?

1$ color sensor. My adventures in electronics continue. While talking with a friend about colors, he told me about color sensors. Later I remembered the video where they sort smarties and so I ...
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2answers
317 views

LED hub purpose?

What is the main purpose of LED hub, is it used only for RGB matrices to connect shift registers for every color or there are some other applications? I'm working with HUB75 and that is the reason ...
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1answer
11k views

Multiple LED's, one controller, diagram included

I want to make sure that my logic is correct and this would work. I'm trying to control 5, 16.4' LED strips of 5050 RGB SMD's at 60 LEDs/m or 300/strip. I want all of them to be ran off the single ...
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1answer
257 views

RGB matrix displays?

I'm working on firmware for LED display composed of Chinese RGB LED matrix modules (1/4 scan, 16x16, RGB). I want to find out how some pictures are displayed in three colors, is there any idea behind ...
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2answers
7k views

How does a PC detect a VGA monitor?

Currently I am trying to connect my LCD to my laptop through a VGA connector. The LCD has 6 wires out of it which I am trying to solder to a VGA male connector, But the laptop doesn't detect the LCD. ...
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1answer
104 views

Can use 17 resistors with 16 rgb led's?

I always see an rgb led ran with 3 resistors, for example a 20ma led on 5v power uses 150ohm's for red due to it's lower voltage but only 100ohms for green and blue. I am running 6 shift registers off ...
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5answers
903 views

Minimizing PCB size of a 192 RGB LED array

I'm working on the design of an LED lamp house for my film scanner. I need RGB LEDs, plus IR LEDs. I'm figuring on a 2"x2" grid of SMD LEDs. Datasheets for the ones I'm using below. The current design ...
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1answer
3k views

Splitting Digital RGB Signal Line to multiple LED strips

I am trying to connect multiple strings of WS2812B RGB LEDs to the same signal line (so that they will all behave the same way, display the same colors, etc). The WS2812B is very time sensitive, so I ...
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1answer
1k views

Controlling multiple RGB leds with PWM from a Atmega328P using one transistor per color

I want to be able to control 9 RGB leds, each color from a potentiometer. Each color needs 20mA, so when all the colors are present the leds will need 540mA (9*3=27, 27*20mA=540mA). My RGBs leds are ...
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1answer
393 views

What kind of IR controller is required to drive a 15m LED strip?

I have to light a 15m RGB LED strip but I don't know how many amps the IR controller (sensor) is required to drive. There are three LED strips, each 5 metres, and I need to connect them together ...
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1answer
427 views

How to calculate image brightness for use with LED panel

I am using a 64x64 RGB LED matrix for which I'm preparing some content. The existing firmware reads RGB888 video files. I'd like to analyse these files before uploading them, to make sure the overall ...
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3answers
2k views

Change RGB leds intensity?

Sorry if this is too basic but I don't understand this issue. Right now, using an MCU, I change the RGB colours of an LED strip with 3 PWM signals. All colours works great . The thing is, when I am ...
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1answer
1k views

rgb led current limit

I am working with RGB LED, my question is will it burn up / get damaged I have already chosen resistors proper for each color of R G B to draw 20mA, but running R G and B at same time draws lots of ...
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1answer
4k views

Driving a RGB Led strip with a RGBW controller

I have a RGB LED strip (Common +) that I want to drive using a controller that expects the strip to also have a W (White) channel. So what I am basicly looking for: As soon as the controllers W ...
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1answer
7k views

powering 12V 5m/16ft 5050 RGB LED Strip with 16V power adapter?

I'm new to the forum found this using google. i have 2 (Two) 5050 RGB 12V LED Strips that are 5M/16ft. It's not as bright as i'd hoped it would be. I double powered one of them with the cheap power ...
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4answers
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Why must resistors be on the respective anode terminals instead of the common cathode terminal of a RGB LED?

Different from the best answer of this one: Why does a resistor need to be on the anode of an LED? But well, I'm also an electronics noob ^.^ Recently I bought the official Arduino starter kit and ...
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2answers
1k views

Show different colors using RGB LED strip and Arduino

I am a beginner, I am following this post to program RGB LEDs (smd 5050). I want few specific LEDs to glow in specific color while other LEDs are glowing in other color. Need help in doing this. I ...
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2answers
13k views

Can I use a 25 meter LED stripe with a single power adapter?

I have 5 stripes of 5m length and 300 RGB LEDs (type 5050) each. One LED consumes about 20 mA at 12 V. Therefore, my whole 25m setup would use about 30 A. Is it safe to connect the 5 stripes series ...
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2answers
2k views

The Transistor Menace - Questions regarding an Arduino rgb LED project

I've been browsing this forum and the internet now for a couple of days and what I thought would be an easy side project turned into a (for me) quite complicated matter. I'm planning to build a mood ...
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1answer
1k views

How a decoded picture is stored in a memory? [closed]

If we decode an image (any format) we will get matrix of pixels. For example consider a picture with resolution 10x10 and colour depth of 16777216. Therefore pixel is represented by 24 (888 RGB) bit ...
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0answers
218 views

RGB Cable Assignments - help

I have a video cable D-Sub 9 pin. Someone know the connector pin assignments to do a RGB 3 bnc cable? Someone can help me? Below, the image of description of the cable
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1answer
1k views

RGB LED audio spectrum analyzer - Bandpass or FFT?

I'm about to build a coffee table which has a RGB LED matrix build in it just like in this video. https://www.youtube.com/watch?v=4NJDgvV8RZw I want the matrix to display an audio spectrum that ...
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1answer
3k views

Raw RGB from CMOS image sensor to grayscale conversion

I am trying to produce an image with OV7740 color image sensor. As far as I know, the sensor is configured by default to provide 10bit parallel RAW RGB data (due to an on-chip Bayer filter). How ...
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1answer
77 views

Change of RGB LED to cheaper one

Right now I'm reading Raspberry Pi Cookbook and I would like to create the program described in the book. Because I'm beginner and I would like to buy more (cheaper) RGB LEDs at once and also I will ...
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1answer
5k views

LED strip segments Parallel vs Serial

I have 5050 RGB LED Strip and an RGB controller (Something like this http://www.amazon.com/SUPERNIGHT%C2%AE-Waterproof-Flexible-300leds-Changing/dp/B00ASHQQKI/ref=pd_sim_MI_3?ie=UTF8&refRID=...
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2answers
4k views

Is it possible to use a ULN2003A Darlinghton array instead of multiple TIP120 transistors?

Looking at the datasheets, I'm not sure their specifics match; TIP127 and ULN2003A My intention is to do something like this, but with the ULN2003A, that I have already: The reason why is that I ...
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1answer
199 views

Prototype for 8x8 RGB LED display [closed]

I am planning to build a small, very low-resolution, 8x8 RGB LED display, which would be able to display a video (some kind of colorful visualization, lo-res) or a picture from PC via DVI or HDMI ...
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1answer
330 views

Can I interchange TIP3055 emitter & collector to avoid needing to insulate the heatsinks?

Using three TIP3055 transistors for RGB LED switching. Collectors are tied to cases. They need to be heat sunk and everything's already mounted and assembled and I don't have time to get rubber ...
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1answer
177 views

What kind of RGB LEDs are these?

I bought these RGB flood lights cause I liked the LEDs I saw in them and I was wondering what kind they are so I can just buy the LEDs and not the whole flood light.
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1answer
1k views

Color Changing LED Circuit upon power on

The circuit I plan to make will have 3 RGB LEDs in it and what I would Like is for it to change colour each time it turns on to a random colour. I'm a beginner level so any help will be greatly ...
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2answers
251 views

Messing with rgb leds and have a question

I have some LEDs that I'm wanting to use in a project. I would like to know what's the best resistor I would need to get the most light out of the 3 different colors using a 12v source. I've measured ...
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3answers
966 views

RGB & Proximity Sensor at about 6 feet

New to this site so hoping it's the right place to ask. I'm trying to prototype something for use in a retail store and an idea a teammate had was using an RGB sensor to detect both ambient color as ...
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0answers
633 views

Mystery while driving a NeoPixel Ring (WS2812) with a GEMMA (ATtiny85)

I am working with an Adafruit GEMMA and NeoPixel Ring 16 LEDs (ATtiny85 and 16 WS2812 leds) and trying to get a program to light the LEDs according to my "pattern" structure below, representing R, G, ...
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1answer
200 views

RGB led driver maximum current

I am planning to build a device that includes an high power RGB LED (either a lightsaber or a decorative object for the girlfriend - I still have to decide), where high power means about 3x3W. I've ...
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1answer
130 views

Most efficient way to convert multiple voltages?

I'm driving a rgb led strip and an arduino from a variable power supply between 12-15 volts. So I'm looking at a buck converter for the 12v led's but I need 5v for the arduino as well. There must be a ...
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1answer
3k views

Arduino project: ultrasonic sensor + 5M 5050 RGB LED strip lights

I'm relatively new to electronics, and as a newbie, I am seeking advice. I'm my current project, I would like to test out the combination of RGB LED strip controlled by one ultrasonic sensor. I am ...
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2answers
15k views

How do I calculate what resistors I need for RGB LEDs with 3.7V? [duplicate]

I have a total of 4 x RGB LEDs. I am hoping to power these as well as a RFduino BLE module with a 3.7V lithium rechargeable battery. I was just wondering how I would go about calculating the ...
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1answer
811 views

HDMI to RGB conversion

I am working on a HDMI dongle based on I.MX6Q with reference to the design files shared in Freescale community. I want to feed HDMI input to processor. As there is no HDMI input available with I....
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3answers
1k views

Dimension RGB LED for peak current

I would like to drive a 3x3 RGB LED matrix multiplexed. This means each RGB LED has 1/9 duty cycle and that means it consumes 1/9 of total current. The RGB LED I am using is designed for max 35 mA ...
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3answers
1k views

Powering RGB Leds from 2 AA batteries

For a hobby project I'm trying to power a PIC microcontroller and 4 RGB leds from two AA batteries. I have both the PIC and the circuit shown below being powered by the batteries and the PIC ...
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2answers
2k views

RGB LED flickering with PWM

I just have issues with the RGB LED flickering under low duty-cycle like 10% on time with 780 Hz. I tried changing the PWM frequency to lower and higher rate but I still see flickering at low duty-...