I am trying to send information to an Arduino Mega 2560 using serial data in order to control both LED Pixel Strips and conventional christmas light strings. I am also using VIXEN lighting software.
I can control one strip of LED pixels from Vixen using this code in the Arduino loop() function;
Serial.readBytes((char*)leds, NUM_LEDS * 3);//buffer to store things in, length (number of bytes to read)
FastLED.show();//refresh the pixel LED's
I can also control a relay (or multiple relays) for the conventional lights using this code;
#define CHANNEL_01 7 //Pin #7 on the Arduino Mega board
void setup()
{
// Begin serial communication
Serial.begin(BAUD_RATE);
#define CHANNEL_COUNT 1
int channels[] = {CHANNEL_01}
int incomingByte[16];
// Define baud rate. This figure must match that of your profile configuration in Vixen!
#define BAUD_RATE 9600
// Set up each channel as an output
for(int i = 0; i < CHANNEL_COUNT; i++)
{
pinMode(channels[i], OUTPUT);
}
}
void loop()
{
if (Serial.available() >= CHANNEL_COUNT)
{
// Read data from Vixen, store in array
for (int i = 0; i < CHANNEL_COUNT; i++)
{
incomingByte[i] = Serial.read();
}
// Write data from array to a pin on Arduino
for (int i = 0; i < CHANNEL_COUNT; i++)
{
digitalWrite(channels[i], incomingByte[i]);
}
}
}
The problem is that I cannot do both of these things. I can either assign the 150 bytes of LED data to the LED strip and it works fine, OR, I can run the relays and they work fine. I have not been able to figure out how to chop up the bytes from the serial data and send it to the appropriate pin. For example, maybe I want to control a relay using pin 7 and a strip of LED pixels using pin 6.
The strip of pixel LED's consumes the first 150 bytes of data from the serial data. But how can I get the next one byte that controls a relay that turns on and off the conventional christmas light string? The byte that controls the light string would be the 151'st in the serial data. Is there a way to specify the 151'st byte? Serial.read() does nothing more than read the first byte (I think). How can a user iterate through the bytes of serial data and select only the ones they want?
To solve this problem I bought an Arduino Uno to run the standard (non-LED) lights separate from the LED lights which run off an Arduino MEGA 2560. The non-LED lights are run on one controller in the Vixen Lights software. The controller has 4 outputs (channels), one for each of the non-LED light sets. Each channel will control one line on a solid state relay. The Arduino Uno runs the relays using this code;
#define PIN1 7 //Pin number seven
#define PIN2 6 //Pin number six
#define PIN3 5 //Pin number five
#define PIN4 4 //Pin number four
#define BAUD_RATE 9600 //just running 4 relay switches so we don't need much speed
#define CHANNEL_COUNT 4 //there are 4 channels coming from the Vixen controller
int bt[4]; //a variable we will use in the loop section of code
int x; //another variable we will use in the loop section of code
void setup() {
delay(1000); //a little delay to give Uno some time on startup
Serial.begin(BAUD_RATE); //set the baud rate of the serial stream
pinMode(PIN1, OUTPUT); //set the four pins on the Arduino Uno to output
pinMode(PIN2, OUTPUT);
pinMode(PIN3, OUTPUT);
pinMode(PIN4, OUTPUT);
}
void loop() {
if (Serial.available() >= CHANNEL_COUNT) {
for (X = 0; x < CHANNEL_COUNT; x++) { //for every channel...
bt[x] = Serial.read(); //we read a byte from the serial stream buffer and store it in an array for later use
}
digitalWrite(PIN1, bt[0]); //we tell the pins on the arduino what to do...
digitalWrite(PIN2, bt[1]); //using the array of integers that holds the byte values from the serial stream...
digitalWrite(PIN3, bt[2]);
digitalWrite(PIN4, bt[3]);
}
}
The LED's run off a second controller in the Vixen Lights software. I have two 12 volt, 50 pixel LED strips of type WS2811. The Arduino uses the FastLED library that can be downloaded for free from FastLED.io. What I found was that there is one byte of garbage data that comes in the serial stream for the LED strips and I had to move past that byte of data in order for the LED's to receive the correct bytes of data to control their color, position etc. I use this code to run my LED's off the Arduino MEGA 2560;
#include <FastLED.h> //include the FastLED library in the Arduino project
#define LED_PIN1 7 //I am going to run one strip of 50 LEDs off of pin 7 on the MEGA
#define LED_PIN2 6 //I am going to run a second strip of 50 LEDs off of pin 6 on the MEGA
#define BAUD_RATE 115200
#define NUM_LEDS 50
//It took me some time to figure out that my two pixel strips are set
//to different color codes. Why? I don't know, but they are.
#define RGB_ORDER RGB //one of my pixel strips is set to use RGB color codes
#define BRG_ORDER BRG //the second strip came from the factory with BRG color codes
#define LED_TYPE WS2811 //what type of LEDs are they? Mine are WS2811, yours may be different.
//create an array to hold the FastLED CRBG code for each of the 50 pixels in the
//first strip.
CRGB leds1[NUM_LEDS];
//create another array to hold the FastLED CRBG codes for each of the 50 pixels in
//the second strip.
CRGB leds2[NUM_LEDS];
int g; //a variable we will use in the loop section
int bufferGarbage[1]; //THIS IS THE KEY TO MAKING THIS WHOLE THING WORK. WE NEED TO
//GET PAST THE FIRST MYSTERY BYTE THAT IS SENT TO THE ARDUINO MEGA FROM THE VIXEN
//LIGHTS SOFTWARE. So we create a variable we will use in the loop section of code.
void setup() {
delay(1000);
Serial.begin(BAUD_RATE);
pinMode(LED_PIN1, OUTPUT); //set our pins to output. PIN1 is pin 6 on the Arduino board.
pinMode(LED_PIN2, OUTPUT); //set our pins to output. PIN2 is pin 7 on the Arduino board.
//This line sets up the first pixel strip to run using FastLED
FastLED<LED_TYPE, LED_PIN1, RGB_ORDER>(leds1, NUM_LEDS).setCorrection(TypicalLEDStrip);
//This line sets up the second pixel strip to run using FastLED
FastLED<LED_TYPE, LED_PIN2, BRG_ORDER>(leds2, NUM_LEDS).setCorrection(TypicalLEDStrip);
}
void loop() {
if (Serial.available() >= 0) { //if there is data in the serial stream
//bufferGarbage is to capture the first byte of garbage that comes across.
//Without this the LED's are out of sync.
//In my case if I didn't capture this byte the first pixel on my
//second LED strip would match the color code that should be on the last
//pixel of the first strip. We don't do anything with this byte.
//but we need to read it from the serial stream so we can move to the
//next byte in the stream.
bufferGarbage[0] = Serial.read();
//then we need to populate the leds1 array so FastLED can tell the pixels what to do.
//We have 50 pixels in the strip and each pixel has a CRGB property that uses
//a red, green, and blue attribute. So for each LED we need to capture 3
//bytes from the serial stream. 50 LEDs * 3 bytes each means we need to read
//150 bytes of data from the serial stream.
for (g = 0; g < NUM_LEDS; g++) {
Serial.readBytes( ( char*)(&leds1[g], 3);
}
for (g = 0; g < NUM_LEDS; g++) {//then we read the next 150 bytes for the second strip of LEDs
Serial.readBytes( ( char*)(&leds2[g], 3);
}
FastLED.show(); //then we tell FastLED to show the pixels!
}
}