LED cushion… enough to make your heart skip a beat?
I’ve been experimenting over the Christmas period with WS2812 RGB LEDs. I intend to write up these experiments in another post, but having a bit of free time enabled me to try something a little more ambitious.
Connecting RGB LEDs to the Raspberry Pi has been simplified and they are now supported in ScratchGPIO once the Pimoroni unicornhat software is installed. By wiring together a bunch of these, I was able to create a 25 LED matrix.
Control via ScratchGPIO was a little slower than I needed and in addition I wanted to see if I could write text. I’ve done this in the past using figlet and writing the result to a Minecraft screen as a pile of blocks. It seemed it might be possible. I originally intended to go for a set of 8×8 LEDs (Similar to the Unicorn Hat or the Sense Hat from Pimoroni) but with time running short for a demo, I had to opt for just 5×5. The maths is what stings here… 25 LEDs, 3 pieces of wire between each, two ends to strip, twist and solder = 150 joints. For 8×8 this would be…. well, ouch!
In the video below, I present the results of the first set of experiments. I fully intend to solder up the remaining 39 LEDs to make 8×8, but this will take some time. I’ve mounted the LEDs on cardboard inside the cushion and covered them with bubble wrap. I will eventually use something much softer in the final product.
The controlling program is written in Python and uses a slight modification of the Unicorn Hat module. It took me a little while to find where Python modules are stored but I found it in
Here’s the final program:
#!/usr/bin/env python
import iprpixel as unicorn
import time
import datetime
import random
from mcpi import minecraft
import commands
#print("Here goes")
lookup=[0,1,2,3,4,9,8,7,6,5,10,11,12,13,14,19,18,17,16,15,20,21,22,23,24]
unicorn.brightness(0.6)
#---------------------
#wr_str = raw_input('What would you like to write? ') # ask the user what they'd like to write at the current position
#wr_str = "Hello"
def choosecol():
colval=random.randint(0,5)
global r_val, g_val, b_val
# print "Colour is :",colval
if colval==0: #red
r_val=255
g_val=0
b_val=0
if colval==1: #green
r_val=0
g_val=255
b_val=0
if colval==2: #blue
r_val=0
g_val=0
b_val=255
if colval==3: #orange/yellow
r_val=128
g_val=128
b_val=0
if colval==4: #cyan
r_val=0
g_val=128
b_val=128
if colval==5: #magenta
r_val=128
g_val=0
b_val=128
def sparklefill():
for led in range(400):
ledpos = random.randint(0,24)
r_val = random.randint(64,255)
g_val = random.randint(64,255)
b_val = random.randint(64,255)
unicorn.setapixel(ledpos,r_val,g_val,b_val)
unicorn.show()
time.sleep(.05)
for led in range(400):
ledpos = random.randint(0,24)
unicorn.setapixel(ledpos,0,255,255)
unicorn.show()
time.sleep(.05)
unicorn.setapixel(ledpos,0,0,0)
unicorn.show()
# time.sleep(.05)
def timestring():
global figletstring, list_line
# wr_str= time.strftime('%I:%M %p')
wr_str= "Time Now : "+time.strftime('%I:%M %p')
figletstring=str(wr_str).upper()
cmd = 'figlet -w 400 -f 3x5 '+figletstring # create an operating system command
line = commands.getoutput( cmd ) # send cmd as a command to the operating system and receive the result.
list_line = line.rstrip().split('\n') # split the result from 'figlet' into separate lines (right strip new line feeds)
def ipaddress():
global figletstring, list_line
figletstring = commands.getoutput( "hostname -I" )
# print figletstring
cmd = 'figlet -w 400 -f 3x5 '+figletstring # create an operating system command
line = commands.getoutput( cmd ) # send cmd as a command to the operating system and receive the result.
list_line = line.rstrip().split('\n') # split the result from 'figlet' into separate lines (right strip new line feeds)
def heart1():
global list_line
list_line = [" "," # # ","#####","#####"," ### "," # "]
def heart2():
global list_line
list_line = [" "," "," # # "," ### "," # "," "]
def displayleds():
for startcolumn in range(len(list_line[1])-4):
column = 0
rownumber=-1
time.sleep(0.1)
for row in list_line: # one row at a time from list_line (the result from figlet)
# print row, len(row)
if rownumber>-1 and rownumber<5:
column=0
# print "working with row",row,"completed"
for letter in row[startcolumn:startcolumn+5]: # work along each row - check each character. If it's a '#' then print a block else leave it as air
if letter == "#":
unicorn.setapixel(lookup.index(column+(rownumber*5)),r_val,g_val,b_val)
else:
unicorn.setapixel(lookup.index(column+(rownumber*5)),0,0,0)
column = column+1
unicorn.show()
rownumber=rownumber+1
def boxdraw():
global list_line, r_val, g_val, b_val
for boxes in range(6):
choosecol()
list_line = [" "," "," "," # "," "," "," "]
displayleds()
time.sleep(0.1)
list_line = [" "," "," ### "," # # "," ### "," "]
displayleds()
time.sleep(0.1)
list_line = [" ","#####","# #","# #","# #","#####"]
displayleds()
time.sleep(0.1)
def pacman():
global list_line, r_val, g_val, b_val
r_val=255
g_val=255
b_val=0
for bite in range(6):
list_line = [" "," ### ","#####","#####","#####"," ### "," "]
displayleds()
time.sleep(0.5)
list_line = [" "," ### ","#####","## ","#####"," ### "," "]
displayleds()
time.sleep(0.5)
def smiley():
global list_line, r_val, g_val, b_val
for flashface in range(5):
choosecol()
list_line = [" ","## ##","## ##"," ","# #"," ### "," "]
displayleds()
time.sleep(1)
def spinner():
global list_line, r_val, g_val, b_val
for boxes in range(5):
choosecol()
for spin in range(4):
list_line = [" ","# "," # "," # "," # "," # "]
displayleds()
time.sleep(0.01)
list_line = [" "," # "," # "," # "," # "," # "]
displayleds()
time.sleep(0.01)
list_line = [" "," #"," # "," # "," # ","# "]
displayleds()
time.sleep(0.01)
list_line = [" "," "," ","#####"," "," "]
displayleds()
time.sleep(0.01)
def heartbeat():
global r_val, g_val, b_val
for hearts in range(10):
r_val=255
g_val=0
b_val=0
heart1()
displayleds()
time.sleep(1)
heart2()
displayleds()
time.sleep(0.25)
for displayip in range(5):
choosecol()
boxdraw()
choosecol()
ipaddress()
displayleds()
time.sleep(1)
while True:
# pacman()
smiley()
spinner()
boxdraw()
heartbeat()
choosecol()
timestring()
displayleds()
time.sleep(1)
sparklefill()
rPi Kitchen 