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4 LED light module for Arduino

by shedboy71

This was a module that I bought called the SPI RGB 5V 4xSMD 5050 LED Light Module for Arduino. Sadly I could not find a great deal of information for it but eventually got it to work. Looking at the module closely you can see that its a 74hc595 based IC that controls 4 SMD LEDs through an SPI interface

SPI RGB 5V 4xSMD 5050 LED Light Module

SPI RGB 5V 4xSMD 5050 LED Light Module

You connect the module to the Arduino as per the table below, I used Vcc and Gnd from the Arduino as well, these are marked on the module connector

Arduino Pin Module Pin



This example requires you to download and install the ShiftPWM library from – https://github.com/elcojacobs/ShiftPWM.

This example is based on the basic RGB Example. It will produce a random flashing effect on all 4 LEDs

[codesyntax lang=”cpp”]

// ShiftPWM uses timer1 by default. To use a different timer, before '#include <ShiftPWM.h>', add
// #define SHIFTPWM_USE_TIMER2  // for Arduino Uno and earlier (Atmega328)
// #define SHIFTPWM_USE_TIMER3  // for Arduino Micro/Leonardo (Atmega32u4)

// Clock and data pins are pins from the hardware SPI, you cannot choose them yourself if you use the hardware SPI.
// Data pin is MOSI (Uno and earlier: 11, Leonardo: ICSP 4, Mega: 51, Teensy 2.0: 2, Teensy 2.0++: 22) 
// Clock pin is SCK (Uno and earlier: 13, Leonardo: ICSP 3, Mega: 52, Teensy 2.0: 1, Teensy 2.0++: 21)

// You can choose the latch pin yourself.
const int ShiftPWM_latchPin=8;

// ** uncomment this part to NOT use the SPI port and change the pin numbers. This is 2.5x slower **
// const int ShiftPWM_dataPin = 11;
// const int ShiftPWM_clockPin = 13;

// If your LED's turn on if the pin is low, set this to true, otherwise set it to false.
const bool ShiftPWM_invertOutputs = false; 

// You can enable the option below to shift the PWM phase of each shift register by 8 compared to the previous.
// This will slightly increase the interrupt load, but will prevent all PWM signals from becoming high at the same time.
// This will be a bit easier on your power supply, because the current peaks are distributed.
const bool ShiftPWM_balanceLoad = false;

#include <ShiftPWM.h>   // include ShiftPWM.h after setting the pins!

// Here you set the number of brightness levels, the update frequency and the number of shift registers.
// These values affect the load of ShiftPWM.
// Choose them wisely and use the PrintInterruptLoad() function to verify your load.
// There is a calculator on my website to estimate the load.

unsigned char maxBrightness = 255;
unsigned char pwmFrequency = 75;
int numRegisters = 1;
int numRGBleds = numRegisters*8/3;

void setup(){

  // Sets the number of 8-bit registers that are used.

  // SetPinGrouping allows flexibility in LED setup. 
  // If your LED's are connected like this: RRRRGGGGBBBBRRRRGGGGBBBB, use SetPinGrouping(4).
  ShiftPWM.SetPinGrouping(1); //This is the default, but I added here to demonstrate how to use the funtion

void loop()
  // Turn all LED's off.

  // Update random LED to random color. Funky!



SPI RGB 5V 4xSMD 5050 LED light module for Arduino


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