Tagged Questions

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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0
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1answer
54 views

LED strip segments Parallel vs Serial

I have 5050 RGB LED Strip and an RGB controller (Something like this ...
0
votes
2answers
98 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 ...
-2
votes
1answer
65 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 ...
2
votes
1answer
76 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 ...
1
vote
1answer
111 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.
1
vote
1answer
75 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 ...
0
votes
0answers
60 views

How to power Common Cathode RGB LED

I'm trying to figure out how to power a common cathode RGB LED. The setup I have below does not work. I assumed power would flow to R, G, and B, and there would be a white light; but nothing. Would ...
1
vote
2answers
85 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 ...
3
votes
3answers
220 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 ...
1
vote
0answers
167 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, ...
3
votes
1answer
81 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 ...
0
votes
1answer
65 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 ...
1
vote
1answer
559 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 ...
3
votes
2answers
323 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 ...
1
vote
1answer
94 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 ...
1
vote
3answers
81 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 ...
1
vote
3answers
402 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 ...
0
votes
2answers
224 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 ...
0
votes
1answer
75 views

Is it feasible to decode an 15 kHz RGB (SCART) signal using a sound card?

Do you know whether it would be feasible to decode an 15 kHz RGB signal (from a video game console) using a sound card ? Providing such input can be captured finely enough by a 192 kHz sound card, ...
1
vote
0answers
83 views

Standard for right angle SMD LED?

I'm trying to specify a SMD LED which has "right angle" mounting, ie edge mounted, with the light going parallel to the horizontal PCB. I need a RGB version (tri-color). Example. As usual, there ...
0
votes
2answers
157 views

Re-design for common anode instead of common cathode

I have a very simple circuit, and I want to use a tri-color LED to indicate which 1 of 3 outputs is on. I currently have a design that works for a common cathode 4-pin LED. However, I have easier AND ...
0
votes
1answer
408 views

driving 4 RGB LEDs with PWM using MSP430

I have a project in which I must drive 4 RGB LEDs using PWM directly from the MSP430. They are separated in two groups of 2 LEDs (1 PWM connection controls one color element of two LEDs) which means I ...
1
vote
3answers
378 views

Control RGB LED without microcontroller

I have an RGB LED that I'd like to change from green to red when a circuit is completed. While I know this is very simple with tools like an Arduino, I'd love to not use a microcontroller. Would it ...
1
vote
1answer
114 views

LEDs flash briefly, but don't stay on [closed]

I've soldered a DC power pigtail to a string of 5V LED lights. When I connect the pigtail to the appropriate power source all of the lights flash very brightly and briefly just as the male end goes ...
2
votes
4answers
207 views

Single transistor instead of RGB screen

In today's screens, each individual pixel is created by the combination of three transistor as Red Green Blue. But, colours are already just different frequency waves. Why aren't pixels made by just ...
0
votes
3answers
174 views

How to transfer from arduino uno to strip board (rgb mood light) [closed]

I am new to circuits and just got a arduino uno. made this simple mood light with it for a project im working on. I used this for a start and just want to know what I need to do to transfer this to ...
2
votes
2answers
750 views

RGB LED brightness levels

Do RGB LEDs have very different brightness levels? I'm running an RGB LED (common cathode) via some TIP120 transistors, controlled from a raspberry Pi. There is a 5v feed from the rPi. Initially I ...
0
votes
2answers
185 views

Controlling RGB LED (common anode) with Arduino

I have an RGB LED (datasheet here) that I want to control using an Arduino R3 (datasheet here). How can I do this? The LED has a common anode, not a common cathode. However, the arduino's I/O pins can ...
0
votes
1answer
47 views

RGB LED and compatible drivers [duplicate]

I need some help regarding LED chips and compatible drivers. I previously included too little detail and spec's so here it is. I have a 50w RGB chip, voltages are red 16-20, green 24-28, and blue ...
-1
votes
1answer
188 views

RGB LED and which drivers

I previously asked a question regarding 50W RGB multi chips and 50W warm white drivers. Here is the driver, a 50W RGB chip draws much lower amperage and compatible drivers usually max out at 650 ...
-1
votes
2answers
172 views

Driving RGB LED's on white LED driver?

Hello I have recently bought a driver for 50w white LED, I was wondering if it is possible to power 50W RGB LED chip via this driver? I know white LED has different amperage, my driver is for warm ...
2
votes
1answer
112 views

Problem with circuit and led

I have made a board for Arduino that has an DS1307 and an L298P. The board looks that it is working correctly. I have an RGB LED at pins 31, 33, 35 and I try to make them HIGH but the volts that ...
1
vote
0answers
702 views

RGBHV (VGA) to YPbPr Converter and Waveforms?

Purely for hobby, I am working on an RGBHV (VGA) to YPbPr (Component) converter circuit for old games consoles modified to output RGBHV on a VGA cable. From the game consoles, the RGB signal is taken ...
0
votes
0answers
199 views

Display controller chip with parallel 24-bit RGB input for video rotation/scaling

I am looking for a display controller chip that has digital video input (parallel 24-bit RGB888) and is capable of scaling and rotating video images to be displayed on a 10" TFT-LCD. I'm streaming ...
4
votes
1answer
487 views

Driving three high power RGB LEDs with PWM, from a 9v battery

I'm building some LED juggling balls. I'm planning to power an Arduino with two AA batteries, and power the LEDs with a 9V battery. I want to drive three of these 3W RGB LEDS in parallel, with PWM. ...
1
vote
2answers
374 views

16 bit RGB to vga converter circuit

Can anyone please suggest a circuit to convert 16 bit TTL (3.3V) RGB signal to a VGA signal. I used a resistor network, it works but I think some active component is necessary for load matching ...
-2
votes
1answer
121 views

are the m74hc595bl and 74hct93 interchangeable?

Im about to put an RGB fader circuit together and it requires the 74hct93. I have quite a few of the 74hc595's. I thought since they are close in name and both shift registers I would ask. 74hc595 ...
7
votes
3answers
753 views

Why do some RGB LEDs have six legs?

Others have four legs, which makes sense to me, as ground can be shared. One of many examples of a six legged RGB LED is the Kingbright KAF-5060PBESEEVGC.
0
votes
3answers
470 views

Control many RGBs by color group using transistors instead of using LED Driver ICs

I have 12 RGB LEDs that I need to control as per the following parameters: -The bulb is on or off -Brightness control of each color group (meaning I dont need control over each color of each bulb) ...
3
votes
1answer
340 views

Read and decode .led file

I'm working on a flexible LED screen persisting of 20 meters of digital RGB LED strip with WS2811 IC for each LED. I want to control this using Arduino, which isn't a problem using FastSPI. My ...
3
votes
4answers
2k views

Voltage regulator too hot to touch [duplicate]

I'm working on an RGB LED project. I'm using this as the power supply: https://www.sparkfun.com/products/114 It uses an LM317 which according to the data sheet can supply up to 1.5A. The LED's I'm ...
3
votes
1answer
287 views

Digital RGB interface EMI filtering

Consider the following system: where: The motherboard contains a LCD controller (SSD1963 from Solomon Systech) and other components (application processor, solenoid drivers, power supplies, etc.) ...
0
votes
3answers
410 views

Inexpensive programmable RGB LED driver/IC/solution?

My desire is to have a simple setup with a dial device (ideal would be a 3 click dial with 3 distinct settings but an analog dial would also be appropriate) whereby position 1 would display a color ...
1
vote
1answer
83 views

What value resistors should I use for this LED?

I'm trying to figure out the actual value resistance I need for the RGB LED I bought from here: http://www.adafruit.com/products/314#Description According to most of the online calculators, for the ...
1
vote
2answers
2k views

Hooking up multiple RGB LEDs while using a minimal number of PWM pins on an Arduino?

I currently have an anode RGB connected to the 11, 10, & 9 PWM pins on my arduino. However I would like to add 3 more LED's to my project, but I don't want to necessarily take up every single PWM ...
1
vote
3answers
656 views

coding using Arduino, two 74HC595 and two RGB LED, problems with shifting out database

the whole point of this was to be able to send 8 bits of color code to 2 rgb leds through 2 74hc595 registers. if i can get the default color for each led to be sent out then the next part of code is ...
0
votes
3answers
324 views

RGB LED Diffuser

I have come across different techniques for diffusing colors. I found Fresnel Lens can be use for diffusing RGB led colors.Is it worth using it or not. I have tested transparent plastic and some ...
4
votes
1answer
129 views

RGB and SRGB difference and their use

I am working on a project which include displaying RGB colors. I would like to know what is the difference between RGB and SRGB. Is it possible to have srgb colors in led. As SRGB has been used for ...
1
vote
1answer
104 views

LED holder modification

I'm working on a project where I will be using a bunch of RGB LED's. I bought a quantity of this style of LED holders: https://www.sparkfun.com/products/11147 The way they work is you slide the ...
-1
votes
1answer
173 views

LED RGBW Lighting, Will this Design work?

I've got this schematic for a very small lighting setup for my basement. The goal is to have two fixtures that have red, green, and blue lights that can be controlled with knobs on a Separate ...