Usb Powered Keyboard Led Lamp




Introduction: Usb Powered Keyboard Led Lamp

here is the thing;
I do a lot of work late at night in my computer, i love to design in the dark, but using photoshop shortcuts gets complicated, so i decided to do something about it , at first went for a lit up keyboard ... naah too expensive, (being a diy´er, everything is doable... therefore expensive)
found this Instructable and eureka

first i thought the power of the LEDs (green lites with 3.v.) was not enough to power my high brightness or superduper leds as the proper commercial name goes. (4.5v?)
so i took power from usb port easier for me .

parts ...
clear acrillyc rod, round is better but since my led bar will be underneath my desk i chose a square rod
six or seven or nine leds , it all depends my bar is 20" (51 cm) long so i used 6 leds 4" (10 cm) appart from each other ..sort of
enough cable to connect the leds , you will need at least 25 " ( why the hell are you still using inches ??? 65 cm)
use the red and black cable , it is imperative that you have to use red and black or else forces unknown of the universe will mess up your life, or go with any color you like.
1 kill switch ... any kind, mine is really small 5mmx10mm (imperial equivalence.. guess it)
you will need a clear ...CLEAR epoxi glue , see the pictures, silicone will work too, but is waaay slower.
double sided tape , to fix in place.
one slice of key lime pie ( you will get hungry.. i was!)

cutter, exacto, carpet knife... get the point?
cable stripper (lol one girl dancing for the cable ...)
electric tape or thermofit or duct tape or masking tape.
pliers to cut led legs
a 7mm drill bit (1/4 ")
electric drill or manual or robotic... press drill is better.
sandpaper the coarser the better
soldering gun and accessories
a spoon.

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Step 1: Go for It

first step.
i used a steak knife, it was really sharp and thin (good thing) to "mark" grooves on the acrillyc at the desired lenght you can use anything you have at your disposal as long as it leaves a clear groove in the acrillyc 1mm deep ... 7mm equals 1/4 do the math.
if you are cutting a round rod , just cut a ring untill you find the point of start. cutting a square rod just cut side by side (exhibit c... jury members)
once marked, lay the rod with the grove aligned with the edge of the table and press firmly and quickly on the ends, this willl snap it leaving a smoth clean cut. (not clean? ... deeper grooves next time) by the way, you can cut plexiglass like this, or even glass but ... nevermind.

Step 2: Making Holes

step two.
measure your rod, find the middle and distibute the leds as you like (this is reallly important, i mean to do it as you like, to fit your project size )
mine are like this (exhibit d)
once you have the locations use a felt marker and .... mark !

i drilled the end holes in the center of the rod, the rest i drilled in an angle 45º to 30º , we want the light beam to bounce inside the rod ( exhibit e.. your honor)

as you can see in the picture i made a previous one clear and holes in 90º angle (not good)
leds are 5mm in diameter , use a bigger drill bit so air can get out of the hole, 7mm , more is ok but less acurate, do not use less or else , the air buble will get inside and reduce brightness.

Step 3: Elbow Grease...

once you have the holes in place, get sand paper, the coarser the better
we want to kill the shine, make it translucent by sanding (i tried solvents , but no good)
sand untill you can´t see no more thru it.
i used a wet sand paper, you can use anything you have at hand even a file or the edge of a cutter blade will do!
remove all dust (or water in my case), make sure the holes are clean, blow air inside the holes to dry them, use mouth, pressured air, hair blower, time, sun ... but get the inside of the holes bone dry .

Step 4: Glues Is My Friend, Not My Enemy...

before you proceed ... test the leds one by one ... better to replace one than having a dead one inside the light bar.

look at the leds , they have a shorter leg , black goes here (negative - ) from the end take 5mm and bend it in an L shape, this will prevent any mistake when placing them in the correct (polarity) order

mix the glue carefull not to make many air bubbles (if you are using more than 8 leds make it in two parts, before u know it , glue is solid)

put a small drop of glue (not bigger than the led itself) inside the first hole and insert the led
CLOSE TO ONE SIDE, THEN MOVE IT TO THE CENTER . this will force the air out and place the glue around the led, if it leaks outside is ok (remember small drops but big enough to fill the gap between the led and walls ) repeat on each hole... aligning the legs properly .

if you get a leak of glue... DO NOT CLEAN IT RIGHT AWAY !!!
wait untill the glues starts to gel, it feels like a gumy bear, then you can cut it or scrap it, it will have "body" but is not yet fixed to the surface
leave a little of glue unused, this will be your reference of curing.

Step 5: Take the Spoon And...

get the key lime pie (home made, instructable cooking up!)
eat it while the glue gels completly ...
im serious, if you rush it , it wont stick.

have no key lime pie??!?!?!
take 10 min.
watch the tv. go to the restroom. go !

Step 6: Wiring ...

get the usb cable... i got mine from an old printer. you can get yours from ... thirft shop? friend?
as long as you GET IT CHEAP OR EVEN BETTER FREE! lol in this times usb cables are everywhere, don´t they?

cut the square part, NOT THE FLAT CONNECTOR
then (carefully) cut the plastic without cutting cables inside (cut like 3 cm/1" from the end)

remove static shield and mesh, not good for us, twist foil and mesh and cut.

identify colors (exhibit x)
cut green and white in uneven lenghts to prevent shortcut no ned to insulate, but be my guest .

connect leds as shown, use red and black !!! or two different colors.
best way for me was cut to distance between leds + room for peeled tip, peel tip, attach to led, then continue to next led

DO NOT SOLDER YET wait untill you have all connections, test it ! works ?...

now you can solder all, in one continuous movement , i think is better !
cut led legs as much as you want .

place double sided tape to fix usb cable in place...
test again! works?
cover cables side with masking tape/duct tape/etc to hold cables in place.

if lights are not working :

check polarity on usb source
check leds polarity
is it on ?
fix then ...

Step 7: Setting in Place...

now turn light bar on one side , leaving cables on the back, put on double side tape and fix in place.
final exhibit your honor...
hide switch, connect to usb, turn on ... and enjoy .


do not try this at home ... go to a neighbor´s home.

im asumming you have some skills like:

basic electronic knowledge
using sharp objects
using epoxic adhesives

you are doing this under your own supervision! if you blow your computer, cut a finger, end up eating glue.. ... get the point?

i´m not an english "native" speaker, grammar and typos will be corrected on request.

comments and ways to improve are welcome.
acid comments will be ignored properly.

support your local key lime pie manufacturer

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    28 Discussions


    7 years ago on Step 7

    I really enjoyed reading the dialog as well and gaining some insight to wiring up some leds. Thanks for the project. D


    11 years ago on Step 7

    Nice work. USB output will be around 5v and you have not used any resistors with LED's...will the LED's last long ? Eventhough the LED can withstand 5V, its still not a good idea to connect LED directly to powersource.... your thoughts are appreciated.


    Reply 11 years ago on Step 7

    Thats the point. You should really use a resistor! Although the USB Specifications limits the max. output to 100mA.
    You can easily calculate the resistor with R=U/I

    P.S. That caused the dead of the first LED (he got the most current)


    Reply 10 years ago on Step 7

    Actually a computer usb port outputs 500mA, and seeing that he has them in a parallel, a 330ohm resistor would do fine. i use the same resistor for up to 12v even!


    Reply 7 years ago on Step 7

    I love you!!!! I have been trying to figure out what resistor to use on my usb/led project and you just shown the light on my wee little project. Thanks


    Reply 10 years ago on Step 7

    You won't get 500mA so easily. The connected Hardware have to *tell* to the Computer that he needs the max. Output (i.e. Printer, HDD)

    But with a simply cable (as here, without a microcontroller), you won't get the full Output current normally. But there are often some variations of the mainboard facturers, of course. With mades the pocket HDD without external power supply possible (need often more than 500mAh)


    11 years ago on Step 7

    So... should we use resistors then? or just more LEDs? I dont know anything about circuits really so.


    Reply 10 years ago on Step 7

    well, you can do both, which ever is preferred, first, it depends on the led's themselves, they generally take anywhere from 30-40mA, and a usb port puts out 500mA, so you could say, take 500/35=14.3, so i would say 15 leds to be safe, or, if you could choose to have less, and just throw a resistor on there, and there are fancy calculations to determine the resistor, but if your using only a few leds, anywhere from 100-330ohm resistor would be fine, just remember, the less leds, the higher resistor you want!

    yogi bear 66
    yogi bear 66

    10 years ago on Introduction

    just buy 9v led's thats what i used on my usbfan/light the hot pink ones look amazing when done right

    Zen Innovations

    There's one thing seriously wrong.... Lack of resistors!! Please use 80 OHM resistor in series with EACH LED. Or you'll loose all the LEDs one by one...then you'll loose the computer one day!!

    unibomb bk
    unibomb bk

    11 years ago on Introduction

    resistors are used for a very big purpose. even more so for each led there should be a resistor for it. but anyway very cool and inventive project. i'm gonna make it today!


    11 years ago on Introduction

    You eat your pie with a spoon (instead of a fork)?
    That's just... ...odd. :) :) :)

    (Next you're going to tell you start eating from the middle of one side of the slice, no less... ;)

    (Nice Instructable, BTW.)


    Reply 11 years ago on Introduction

    well ... it was so creamy i felt like eating w a spoon... lol! tx ;)


    11 years ago on Step 7

    Cool idea add a bit of brass tube and a vegetarian looking stand and you would have a nice free standing keyboard lamp.


    11 years ago on Introduction

    Scope: Very nice! Thanks for the idea/instructable.

    Could anybody please comment about the resistor? If we want to do that, what do we need?


    11 years ago on Step 7

    Hey scopevisions! good work! I wanna do something like that, the only differencce is that i´m going to illuminate the keyboard under the keys like the logitech keyboard... Keep doing more projects and giving ideas! Good life man!

    awww. i feel so stupid. i thought the light bar was some how going to be put into the keyboard. i had to read the whole instructable to find out i was wrong.