#Rpi-ws2812-server This is a small program for driving the WS281x (a.k.a. NeoPixel) LEDs from a webserver, command line, text file, Python,... using the Raspberry Pi. It uses the rpi_ws281x PWM driver code from jgarff (https://github.com/jgarff/rpi_ws281x). The LEDs can be controlled by sending text commands to a tcp socket. These commands can be generated by a webserver script, android app,... It's also possible to control the leds directly from the command line or by loading text file containing some predefined color patterns.

#Installation On the raspberry you open a terminal window and type following commands:

• sudo apt-get update
• sudo apt-get install gcc make git
• git clone https://github.com/tom-2015/rpi-ws2812-server.git
• cd rpi-ws2812-server
• make
• sudo chmod +x ws2812svr

On newer Raspbian (Jessie) operating system the audio output is activated by default, you need to disable this: You can do this by blacklisting the sound module: sudo nano /etc/modprobe.d/snd-blacklist.conf

blacklist snd_bcm2835

also in /boot/config.txt you comment out the audio=on parameter:

# Enable audio (loads snd_bcm2835)
#dtparam=audio=on

#Testing Connect your LEDs to the PWM output of the Raspberry Pi and start the program:

• sudo ./ws2812svr

Now first initialize the driver code from jgarff by typing 'setup'. On the following line you must replace 10 by the number of leds you have attached!.

• setup 1,10
• init

Now you can type commands to change the color of the leds. For example make them all red:

• fill 1,FF0000
• render

#Supported commands Here is a list of commands you can type or send to the program. All commands have optional comma seperated parameters. The parameters must be in the correct order!

• Setup command must be called everytime the program is started:

setup  
    setup 
		<channel>, 						#channel number
		<led_count>, 					#number of leds in channel
		<led_type>, 					#type of led (3 color or 4 color) default 0
		<invert>, 						#invert output, default 0
		<global_brightness>, 			#global brightness level for channel (0-255), default 255
		<gpionum>						#GPIO output number, 18 for PWM0 = pin 12, 24 for PWM1 = pin 35, default 18
	
	Possible LED types:
		0 WS2811_STRIP_RGB
		1  WS2811_STRIP_RBG
		2  WS2811_STRIP_GRB
		3  WS2811_STRIP_GBR
		4  WS2811_STRIP_BRG
		5  WS2811_STRIP_BGR
		6  SK6812_STRIP_RGBW
		7  SK6812_STRIP_RBGW
		8  SK6812_STRIP_GRBW
		9  SK6812_STRIP_GBRW
		10 SK6812_STRIP_BRGW
		11 SK6812_STRIP_BGRW

    Example:
    setup 1,10,0

• Render command sends the internal buffer to all leds

render   
    <channel>,          #send the internal color buffer to all the LEDS of <channel> default is 1  
    <start>,            #before render change the color of led(s) beginning at <start> (0=led 1)  
    <RRGGBBRRGGBB...>   #color to change the led at start Red+green+blue (no default)  

• rotate command moves all color values of 1 channel

rotate  
    <channel>,         #channel to rotate (default 1)  
    <places>,          #number of places to move each color value (default 1)  
    <direction>,       #direction (0 or 1) for forward and backwards rotating (default 0)  
    <RRGGBB>           #first led(s) get this color instead of the color of the last led  

• rainbow command creates rainbows or gradient fills

rainbow  
    <channel>,         #channel to fill with a gradient/rainbow (default 1)  
    <count>,           #number of times to repeat the rainbow in the channel (default 1)  
    <start_color>,     #color to start with value from 0-255 where 0 is red and 255 pink (default is 0)  
    <end_color>        #color to end with value from 0-255 where 0 is red and 255 pink (default 255)  

• fill command fills number of leds with a color value

fill  
    <channel>,          #channel to fill leds with color (default 1)  
    <RRGGBB>,           #color to fill (default FF0000)  
    <start>,            #at which led should we start (default is 0)  
    <len>               #number of leds to fill with the given color after start (default all leds)  
	<OR,AND,XOR,NOT,=>	#bitwise operator to execute on OLD and NEW color, default = copies new color to output

• delay command waits for number of milliseconds

delay  
    <milliseconds>      #enter number of milliseconds to wait	  

*brightness command changes the brightness of a single or multiple leds without changing the actual color value

	brightness 
		<channel>,		 #channel number to change brightness (default 1)
		<brightness>,	 #brightness to set (0-255, default 255)
		<start>,		 #start at this led number (default 0)
		<len>			 #number of leds to change starting at start (default led count of channel)

*fade command changes the brightness over time

	fade 
		<channel>,						 #channel to fade 
		<start_brightness>,				 #start brightness (default 0)
		<end_brightness>,			     #end brightness (default 255)
		<delay ms>,						 #delay in ms
		<step>,							 #step to increase / decrease brightness every delay untill end_brightness is reached
		<start_led>,					 #start led
		<len>							 #number of leds to change starting at start (default is channel count)

*gradient command makes a smooth change of color or brightness level in a channel

	gradient
		<channel>,						 #channel number to change
		<RGBWL>,						 #which color component to change, R = red, G = green, B = blue, W = white and L = brightness level 
		<start_level>,					 #start at color level (0-255) default is 0
		<end_level>, 					 #end at color level (0-255) default is 255
		<start_led>,					 #start at led number (default is 0)
		<len>							 #number of leds to change (default is channel count)

*random command can create a random color

	random 
		<channel>,						#channel number to change
		<start>,						#start at this led
		<len>,							#number of leds to fill with a random color, default is channel count
		<RGBWL>							#color to use in random can be R = red, G = green, B = blue, W = White, L = brightness also combination is possible like RGBW or RL

#Special keywords You can add do ... loop to repeat commands when using a file or TCP connection.

For example the commands between do and loop will be executed 10 times:

do   
   <enter commands here to repeat>    
loop 10

(Endless loops can be made by removing the '10')

For do ... loop to work from a TCP connection we must start a new thread. This thread will continue to execute the commands when the client disconnects from the TCP/IP connection. The thread will automatically stop executing the next time the client reconnects (ideal for webservers).

For example:

thread_start   
   do  
      rotate 1,1,2  
     render  
     delay 200  
  loop  
thread_stop  
<client must close connection now>   

#PHP example First start the server program:

• sudo ./ws2812svr -tcp

Then run the php code from the webserver:

//create a rainbow for 10 leds on channel 1:  
send_to_leds("setup channel_1_count=10;rainbow;brightness 1,32;");  
function send_to_leds ($data){  
   $sock = fsockopen("127.0.0.1", 9999);  
   fwrite($sock, $data);  
   fclose($sock);  
}

#Command line parameters

• sudo ./ws2812svr -tcp 9999
  Listens for clients to connect to port 9999 (default).
• sudo ./ws2812svr -f text_file.txt
  Loads commands from text_file.txt.
• sudo ./ws2812svr -p /dev/ws281x
  Creates a file called /dev/ws281x where you can write you commands to with any other programming language (do-loop not supported here).