5. SEW ON YOUR LEDS
5a. Attach the cathode end of each
LED to a row, and the anode end of
each LED to a column (or vice versa).
If you did not take steps during the
soldering phase to differentiate the
cathode from anode leads, you will
have to make the distinction now.
The cathode end of the LED is often
marked with a green line on the front
or back of the surface mount package.
If you are able to find this marking
despite your soldering, you can use
it. Otherwise, learn to distinguish the
direction from the appearance of the
face of the LED. Test one by running
a current through it for reference. Be
careful to use a voltage and current
appropriate for your LED.
5b. While sewing, take care to make
good connections between your
thread and each bead, looping the
thread through each bead several
times, as shown here.
The fastest way to sew is to stitch
each row and column continuously,
not stopping to tie off the thread
for each LED. In other words, sew
in the cathode end of one LED, and
sew down your row to the next LED
cathode without cutting your thread.
However, this makes replacing badly
sewn or broken LEDs harder, since
you’ll have to cut the continuous
thread and tie the ends off in the
event of a problem.
Alternatively, you can sew each LED
on individually. This will make repairs Q: Can I do anything to make sure my LEDs won’t break off?
easier, but your sewing will take much A: Before you sew any of the LEDs, abuse them a little to
longer. I chose the first option for faster test your solder joints: twist and tug on the beads. The weaker
sewing, but I did have to replace a joints will break and you’ll be left with the sturdy LEDs. I tried this method on the second shirt I made and not one of my LEDs has
few LEDs. broken since I sewed it, and they’ve even withstood a few washings.