Control a 3W RGB LED with an Arduino

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I’m not sure how to do this. I have this LED – the 4 pin 3E RGB led.

I want to be able to control it using an Arduino (ideally I would control 4 – 6 LEDs). By controlling I mean not only control the color but also turning it on and off.arduinoledShareEditFollowFlagedited 3 hours agoJRE44.5k88 gold badges7373 silver badges123123 bronze badgesasked yesterdayGB54155 bronze badges

• 2I think this question can be answered with a quick google search. – Damien yesterday
• 3I’m voting to close this question because it lacks of research – Damien yesterday
• 2You need a 350 mA PWM low side driver for 3 ch. and a large heat sink. What’s the problem? Choosing a 1V 15A FET? – Tony Stewart Sunnyskyguy EE75 yesterday 
• 2You need 3 switches, controlled by arduino. Best choise MOSFETs. – user263983 yesterday
• 1Your web link is very good, because it shows a big variety of products, and also give detailed description of specifications of physical and electrical properties. For newbies, I would recommend to prototype with low power (1W per LED), and more pins (2 pin per LED). My suggestion is this one: 3W RGB 6 Pin 3V 350mA Power LED i.imgur.com/UgfFkHj.jpg. – tlfong01 yesterday    
• (1) I suggest low voltage (3V) and low power (1W), low current (350mA) because for higher power, 6V/12, 3~5A power LEDs you need 5V/12V power MOSFET PWM switches. (2) I suggest 6 pin, instead of 4 pin (fixed common Cathode/Anode) modules, because you have more flexibility in circuit design. (3) For playing with power LED PWM, I suggest to try the following cheapy (US$0.9) PWM module: AliEXpress Diymore LED Lamp Driver PWM Dimmer DC7-30V to DC1.2-28V 350mA 1W DC-DC Converter Buck Step Down Module / to continue, … – tlfong01 yesterday    
• es.aliexpress.com/item/… Have a great power LED lamp project. Good luck. Cheers. – tlfong01 yesterday   
• I forgot two more things. (1) For preliminary testing, you don’t need to use Arduino. You can use the following handy testing tool to get the Voltage/Current/Brightness charteristics: AliEXpres Diymore-DC-DC Step-Down Button Adjustable Power Supply Module with LCD Display DC5-23V to DC0-16.5V 3A US$ 2.84: / to continue, … – tlfong01 yesterday   
• es.aliexpress.com/item/…. – tlfong01 yesterday   
• If you later want to do precise PWM LED control, you can consider this cheapy US$2 goody: XY-LPWM 1Hz-150Khz, PWM Pulse Frequency Cycle Adjustable Signal Generator Module 3.3V-30V LCD Display US$1.72 es.aliexpress.com/item/…. Cheers. – tlfong01 yesterday   
• TonyStewartSunnyskyguyEE75 That (Electronics is not my beach) and also the fact that I don’t really understand where for instance I would connect the signal data port from arduino to the led (according to the description one is the positive,which I assume cant be the signal port and everything else is ground?) and on my search i didnt found any project using rgb 3w with 4 pins explaining it. @tlfong01 thanks! I’m going to look through the material you recommended and see if i can come up with something. – GB5 yesterday
• @GB5, You are welcome. For newbies, I would recommend to start with just one single 350 mA LED, instead of all three R, G, B together. When you are going well, then you can of course do more LEDs, even 5!: i.imgur.com/eCLayJx.jpg. PS – to drive a 350mA load you need a transistor to help. eg Arduino drives 2N2222 (Ic 800mA max), which in turn drives one or two LED. Or you need more more powerful drivers to entertain more LEDs.. – tlfong01 13 hours ago   
• @GB5, I must first confess that I have very little experience with power LED lamps. So my suggestions here might be simply wrong or misleading. Anyway, I am going to explore using my poorman’s cheapy tools. I will be writing some research reports now and then. It it only after I have some confidence that I am not doing stupid things, then I would consider writing an answer to you question, mainly for power LED newbies. Now I heard that Cree’s power LED is the best brand. So I googled to know more, like why there is an aluminium back plate and how to do the soldering. / to continue, … – tlfong01 11 hours ago   
• I am studying the Cree’s 5 x 3W models, before experimenting a single 1W model. 5x3W Cree XPE XP-E High Power LED Emitting Diode, Neutral White Cool White Warm White Red Green Blue Yellow with PCB – US$4.5/5 pcs es.aliexpress.com/item/… – tlfong01 10 hours ago   
• I knew Cree’s 3W LED lamps would be too bright/dazzling for my eyes. So I decided to try the 1W LED’s first. I wired 4 single LEDs, R,G,B,Y and use the button adjustable regulator to test the brightness. I found the results very disappointing: (1) Red and Yellow turns on at around 1.7V, Yellow turns on above 3V, and Blue only turns on at around 3.3V. At this voltage, other three RGY become very dazzling and I need to use a shade, so not too blind my eyes. I have too many photos to upload in the comments here. So I am uploading them as part of my answer. – tlfong01 6 hours ago   

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1 Answer

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Question

How to use Arduino to control 3W RGB LED lamps?

Answer

Part 2 – RGBYW LED I-V Measurements

1. Red LED V-I-B Test

2. Blue LED Testa. 2.7V, 10mA Turning point, dim to pale brightb. 3.2V, 87mA Brightc. 3.3V, 102mA Very bright, but not dazzling

Part 1 – Preliminary Testing of RGB 1W LED lamps

I knew Cree’s 3W LED lamps would be too bright/dazzling for my eyes. So I decided to try the 1W LED’s first. I wired 4 single 1W LEDs, R, G, B, Y and use a button adjustable regulator to test the brightness.

I found the results very disappointing:

1. Red and Yellow turns on at around 1.7V,
2. Yellow only turns on at around 3V, and
3. Blue only turns on later at around 3.3V.

At this voltage level of 3V3, other three RGY become very dazzling and I need to use a shade to soften/darken the lights, so not to blind my weak eyes.

I have too many photos to upload with the comments. So I am uploading them as part of my answer here.

References

(1) AliExpress YD-XGJH RGB/RGBW/RGBWY LEDs, 3W/9W/12W/15W, 2/4/6/8 pins – US$5 ~ US$110 (The 3W RGB LED the OP hopes to control by Arduino)

(2) AliExpress Chanzon – Aluminum Heatsink Base Plate 1W, 3W, 5W LED PCB Board, 20mm Heatsink Substrate, 20mm Star Kit, for 1, 3, 5W – US$1.56-2.59

(3) AliExpress 5x3W Cree XPE XP-E High Power LED Emitting Diode, Neutral White Cool White Warm White Red Green Blue Yellow with PCB – US$4.5/5 pcs

(4) P2N2222A Amplifier Transistors NPN Silicon – OnSemi

(5) ULN2003 Seven Darlington arrays Datasheet – ST

(6) ULN2803 ULN2803A Darlington Transistor Arrays Datasheet – TI

Appendices

Appendix A – Testing 3 independent 350mA LEDs (recommended to newbies)

Appendix B – RGBYW 5 x 3W (Warning – Ninjas only)

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• Wow, sweet! Could you just add the schematics? Your answer is going to be my reference for while =D – GB5 3 hours ago
• @tlfonf1: You’ve shown that it can be done, but not how. The how is the important bit, and belongs in the answer, not in some link. – JRE 3 hours ago
• The trick is not just in doing it, but in doing so safely and reliably. 3W is (comparatively) a lot of power. Just brutally PWMing the LEDs may “work” but burn them out in short order. You need to be sure that you won’t exceed the current limits for the LEDs. The LEDs may be able to withstand higher current for short periods – maybe the PWM pulses are short enough. Who knows. There’s no data on pulse current on the site, and no datasheet. – JRE 2 hours ago
• @JRE, Well, I agree. For now, I am just messing around, making mistakes, frying LEDs, and learn lessons. Now It is only Part 1. Part 2 is making measurements, basically V-I-P-B (Voltage-Current-PWM, Brightness) curve tracing/plotting, sort of writing spec/datasheet. Part 3 is basic circuit design, and of course schematics, …, Stay tuned, … 🙂 – tlfong01 1 hour ago   
• #GB5 and JRE, I am bearing in mind the rough voltage and current limit from the Op’s datasheet: For Red LED, voltage is 2.6V, current is 500mA. Part 2 measurement starts with Red LED. My firing budget is 5 damn cheap LEDs per day, … :), – tlfong01 1 hour ago   

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