This post is all about Interfacing RGB LED Strip with Arduino to see fading & rolling of LED in different colour effects.
Overview
In this tutorial, we are going to learn about how to connect a 12v RGB LED Strip with Arduino and how to program Arduino Board to make different colour combinations and fading animations. This RGB Multi-Color LED Strip is Dimmable and can be used to make many DIY LED Projects.
This Strip is a perfect choice for indoor or outdoor decoration on Diwali, Christmas, Parties, Marriage or on other events. Light will change colors and speed automatically and periodically on your choice. It has not only RGB (Red, Green, Blue) but a 16 multicolored Light changer. You can have the DIY selection to create your great led mood lighting.
Check this post: RGB LED Strip Color Control with Bluetooth & Arduino
Bill of Materials
Following are the components required to make this project. All the components can be easily purchased from Amazon. The purchased links are given below:
| S.N. | Components | Quantity | Purchase Links |
|---|---|---|---|
| 1 | Arduino UNO Board | 1 | Amazon | AliExpress |
| 2 | 12V RGB LED Strip | 1 | Amazon | AliExpress |
| 3 | MOSFET IRF540N | 3 | Amazon | AliExpress |
| 4 | 12V Power Supply | 1 | Amazon | AliExpress |
| 5 | Connecting Wires | 20 | Amazon | AliExpress |
| 6 | Breadboard | 1 | Amazon | AliExpress |
12V RGB LED Strip
The SMD5050 type 12V RGB LED Strip is very popular in market. It operates at 12V, 1.5A DC Power Supply. It can generate colours like RGB, White, Warm White, Red, Green, Blue, Yellow etc. There are a total of 60 LEDs per piece.
The RGB LED Strip has SMD5050 which has 3 samll sized LED of red , green & blue colour. All the 3 LED has 3 resistors attached to it to prevent the LED from getting damaged due to over voltage.
It has cutting marks after each 3 SMD5050 and is detachable. It has a 3M double-sided adhesive and at the back, it has double-sided copper conductive PCB with a great heat dissipation.
The RGB LED strip has 4 pins with 4 colors like white, red, green, blue. The white color line for supplying 12V Power Supply to it. The 3 RGB line is for supplying digital output signal from microcontroller.
Current/Power Requirements for RGB LED Strip
The problem with the Arduinois that its digital outputs can supply more than 200mA and this strip at full brightness could draw more than 1A. For that we have to put something between the Arduino PWM signal and the LED strip. To do this we have two options, either to use high power BJT or to go with MOSFET.
I tested the current consumption by RGB LED Strip at different conditions. When its glowing to full brightness, the current goes more than 1A. So it is advised to use an adpater of 12V, 1.5A or higher current rating.
Interfacing RGB LED Strip with Arduino
Now let us learn about interfacing SMD5050 LED Strip with Arduino. For each colour line, we need 1 MOSFET and they need to be rated to handle the max current. It’s about 330mA per meter for each channel, 1.66 A per channel for a 5-meter strip.
I have used an IRF540N N Channel MOSFET. You can use any NPN transistors like TIP120, TIP121, TIP122 of N-Channel MOSFETs like IRF2807, IRF 530, IRFZ44N based on your application you can change the transistors. The difference between these transistors is that they have a different collector-emitter current rating. For example, if you are using a large length of RGB LED strip then to drive them you will be needing high current transistors like IRF540 which have Drain Current (Id): 28 Amps.
Connect the IRF540N MOSFET and RGB LED Strip as shown in the Circuit Diagram above. Connect the 1st Pin of IRF540N which is a GATE pin to Arduino PWM Pin as D6, D5, D3 respectively for RGB pin. The 2nd pin of IRF540N MOSFET which is a Drain Pin is connected to RGB LED Pins. And the Source Pin of IRF540N which is the 3rd pin is connected to GND. The IRF540n is working as a switch here. You need to supply 12V DC from external power supply like DC Adapter or 12V Transformer rectifier Circuit.
Source Code/Program
The Source Code for Interfacing RGB LED Strip with Arduino with Fade & Rolling Color Effect is given below. There is no need of any library for this. You can simply upload the code to the Arduino board.
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#define RED_PIN 6 #define GREEN_PIN 5 #define BLUE_PIN 3 // # of milliseconds to pause between each pass of the main Arduino loop #define Loop_Delay 30 //brightness level of each color (0..255) int Brightness_R; int Brightness_G; int Brightness_B; //fade step counter for LED cycle through off (510 steps), fade on (255 steps), // on (510 steps), fade off (255 steps) 1530 total steps int FadeStep_R; int FadeStep_G; int FadeStep_B; //number of times LED has completed a full fade cycle // int CycleCountB; // int CycleCountR; // int CycleCountG; //used to establish what values to send to LED strip // int ColorValue; // ===================================== // ARDUINO SETUP ROUTINE // ------------------------------------- void setup() { //Serial.begin(9600); pinMode(RED_PIN, OUTPUT); pinMode(GREEN_PIN, OUTPUT); pinMode(BLUE_PIN, OUTPUT); //set initial strip color. 0(off) to 255(on). can be anything or nothing. //This value is constrained to 0 - 255. any number higher than 255 will be rounded down to 255. // any number lower than 0 will be rounded up to 0. Brightness_R = 0; Brightness_G = 0; Brightness_B = 0; //Set starting fade step position. -764 to -255 = on (brightness level is 255) // -254 to 0 = fading on (this number *-1 = brightness level) // 0 to 510 = off (brightness level is 0) // 511 to 765 = fading off (this number - 510 = brightness level //must each be 510 steps apart for smooth color pauses. //if pauses removed by commenting out or removing ColorValue if statements and rplacing //with setLEDS (Brightness_R, Brightness_G, Brightness_B); ,which I've already done, these number //can be any value from -764 to 765 in any combantion, likely making many unplesant fade patterns, //but also with many possibilities for interesting patterns. If all values are 510 steps apart //the results will ROY G BIV either forward or backward and starting at different positions //depending on the values given. the farther off the 510 steps of seperationg the further from //ROY G BIV the pattern will move. FadeStep_R = 0; //0 These setting for normal ROY G BIV FadeStep_G = 325; //510 FadeStep_B = 650; //-510 //Set each LED's fade cycle counter to 0 // CycleCountB = 0; // CycleCountR = 0; // CycleCountG = 0; } // ===================================== // ARDUINO MAIN LOOP ROUTINE // ------------------------------------- void loop() { //decrement each LED's fade step counter by one at the start of each loop FadeStep_R = FadeStep_R - 1; FadeStep_G = FadeStep_G - 1; FadeStep_B = FadeStep_B - 1; //fade red LED according to it's fade step counter. if (FadeStep_R == -764) {FadeStep_R = 765;} if (FadeStep_R < 0) {Brightness_R = FadeStep_R * -1;} if (FadeStep_R >= 510) {Brightness_R = FadeStep_R - 510;} // if (FadeStep_R == -510) {CycleCountR = CycleCountR + 1;} //count + 1 for each full fade cycle //fade green LED according to it's fade step counter. if (FadeStep_G == -764) {FadeStep_G = 765;} if (FadeStep_G < 0) {Brightness_G = FadeStep_G * -1;} if (FadeStep_G >= 510) {Brightness_G = FadeStep_G - 510;} // if (FadeStep_G == -510) {CycleCountG = CycleCountG + 1;} //count + 1 for each full fade cycle //fade blue LED according to it's fade step counter. if (FadeStep_B == -764) {FadeStep_B = 765;} if (FadeStep_B < 0) {Brightness_B = FadeStep_B * -1;} if (FadeStep_B >= 510) {Brightness_B = FadeStep_B - 510;} // if (FadeStep_B == -510) {CycleCountB = CycleCountB + 1;} // count + 1 for each full fade cycle // if step counters are intialized 510 steps appart, -510 is the step in each LED's fade cycle // that it will be on full brightness while the other 2 LED's are off. Brightness_B = constrain(Brightness_B, 0, 255); Brightness_G = constrain(Brightness_G, 0, 255); Brightness_R = constrain(Brightness_R, 0, 255); // if (CycleCountB == 8) {CycleCountB = 0;} // if (CycleCountR == 8) {CycleCountR = 0;} // if (CycleCountG == 8) {CycleCountG = 0;} // if (CycleCountR == 2) {ColorValue = 1 ;} //set point for pattern to pause on red // if (CycleCountR > 2) {ColorValue = 0;} // if (CycleCountG == 4) {ColorValue = 2;} //set point for pattern to pause on green // if (CycleCountG > 4) {ColorValue = 0;} // if (CycleCountB == 6) {ColorValue = 3;} //set point for pattern to pause on blue // if (CycleCountB > 6) {ColorValue = 0;} //Send brightness levels to LED strip setLEDS (Brightness_R, Brightness_G, Brightness_B); // if (ColorValue == 0) {setLEDS (Brightness_R, Brightness_G, Brightness_B);} // default to fade pattern // if (ColorValue == 1) {setLEDS (255, 0, 0);} //LED strip red // if (ColorValue == 2) {setLEDS (0, 255, 0);} //LED strip green // if (ColorValue == 3) {setLEDS (0, 0, 255);} //LED strip blue // slow the loop down a bit delay (Loop_Delay); } // send the LED levels to the Arduino pins void setLEDS (int ipR, int ipG, int ipB) { analogWrite (RED_PIN, ipR); // send the red brightness level to the red LED's pin analogWrite (GREEN_PIN, ipG); analogWrite (BLUE_PIN, ipB);} |
Results
Once the code is uploaded and 12V supply is turned on you will start seeing the LED rolling and fading effect. Some of the LED fading pictures are given below and for full demonstration go through the video below.
1 Comment
After reading this post about how to control the brightness of a LED strip, I have a question about how you are controlling the brightness of the LED strip. Are you “adjusting” the value for each R G B pin and not the voltage to the strip? If so, since the Pin values range from 0 to 255, then am I correct in a value of 128 would turn on the color 50%?