Picture of turn signal biking jacket
This tutorial will show you how to build a jacket with turn signals that will let people know where you're headed when you're on your bike. We'll use conductive thread and sewable electronics so your jacket will be soft and wearable and washable when you're done. Enjoy!

A version of this tutorial is also on my website.

Step 1: Supplies

Picture of supplies
Get your supplies. You need:

-- LilyPad Arduino main board
-- FTDI connector
-- mini USB cable
-- LilyPad power supply
-- 16 LilyPad LEDs (note: these aren't available from SparkFun yet, but will be soon)
-- 2 push button switches
-- a spool of 4-ply conductive thread
-- a digital multimeter with a beeping continuity tester. This is the one I have.
-- a garment or a piece of fabric to work on
-- a needle or two, a fabric marker or piece of chalk, puffy fabric paint, a bottle of fabric glue, and a ruler
(Available at your local fabric shop or Joann Stores.)
-- a pair of scissors
-- double sided tape (optional)
-- a sewing machine (optional)

disclosure: I designed the LilyPad, so I'll make some $ if you buy one.
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Viniciusoh2 months ago

If there's anyone wondering about the links that aren't working, I've found them here:


And for the code:


Now the link is hosted at MIT.

Also, wonderful project! If here in brazil would be easy to buy those boards, for sure I would do it!

lclaiborne2 months ago

I've been commuting, racing and touring since 1978. Honestly? This is really cute for nightclubs, but in the real world of urban riding it's waste of time. Drivers who actually pay attention see hand signals, but this? It's only going to be visible at night, and assuming drivers are actually paying attention. Better you all learn how to manage traffic, as in looking over your shoulder to see what's behind you, looking at drivers eyes to see if they see you, all the skills an urban rider already has. This garment will only promote sloppy dangerous riding and get people killed. It's not a new idea. LED turn signals on helmets have already died in the marketplace out of apathy - it's heavy high maintenance stuff that costs a lot of cash for little benefit. And at least those wouldn't be a stinking gamey mess after a ride. How do you wash this? What about rain? How do you intend to deal with high temperature weather with fabrics that won't support all this stuff? Where I live we wear all cotton t shirts to ride in half the year because of hot weather. That won't support the lights and wires. Then there's sweat corrosion. Then there's the plain old who needs the hassle of a complicated shirt when a spread of AA battery blinky lights on bike and helmet works better to be visible.

Sorry if this sounds harsh, It's not meant to be, but my years as messenger taught me a lot about city riding and extra high maintenance stuff you can't wash is useless. The brain is our best tech - watch behind you for cars and turn when there's room. The cagers won't pay any attention to this. Bike turn signals date back to at least the 1920's. They'd be standard if they did any good.

I can think of a bunch of other apps for this tech in sporting goods, but the problems of sweat and complicated maintenance would need to be addressed. And the power unit.

TheMaciej2 months ago

Okay, does it have street homologation or is it only for offroad ?

peinkc2 months ago

I haven't been on a bike for years but this is one of the best ideas yet.
Take it to Shark Tank ASAP

omikeo2 months ago

How far/often do you ride, what type of bike do u have ?

NonofYabiz2 months ago

A wonderful idea! :)

dalauner2 months ago

I've done a similar project only with a professional cycling shirt:


cowcrusher2 months ago

Did anyone already suggest adding reflective tape in a fashionable way so that drivers see you first? I noticed that these jackets used are dark which is for the contrasting "arrow board" to be noticed but not for instances of poor visibility such as rain or fog. Great project though.

zainulislam3 months ago
any one please help me to learn arduino i want to learn arduino i send you money of classes my email
jamesr124 months ago

you have the code to turn the left signal off and the right on and off to flash but for the left signal do you just do the same have the right turned off and the left on and off for flashing and do you just input the code under the loop or what

hello sir i am new here and in arduino so iwant to learn arduino programing and every thing about arduino so if you khow about programing so please help me to learn arduino sorry for my poor english thanks in advance i am very thankful to you please give me replay to my email

my email:-zainulislam23@gmail.com
skype id:-zainulislam49
jamesr124 months ago

is the info about the power supply all you need to know for the power requirements for all the components or is there more power reqs needed

ArvinL5 months ago

Well, get one of these http://shooln.co.uk/bike-led-signal-jacket.html. Both the jacket and remote control are waterproof, wireless remote control, got 4 buttons (rather than 2 like in this article), and less hassle to buy stuffs, program and build. I bought one from them and couldn't be happier!

Claudia O5 months ago

FTDI serves to put the program in Lilypad

jamesr125 months ago

hi i am new to this stuff and just wondered what the FTDI connector is used for sorry ia m reserching for a project

Claudia O5 months ago

Hello, I was wondering if we can use a two ply conductive thread however a four ply one. Thaaaanks!!

How do we make this project waterproof? I understand it not being machine washable, of course, but I need some way to clean it, some insurance that it's not going to short and burn me because it started raining...

I can't believe I had to scroll all the way down here to find this concern. I like the idea, but the first thing that came to mind when I saw it was rain.

I WAS going to suggest Liquipel (http://www.thedailyserge.com/2012/03/tech-tuesdays-vol-25-waterproof.html?spref=fb) until I remembered that Liquipel is more of a SERVICE than a product. Add to that I don't even know if the machinery is equipped for clothing. NEVER FEAR: The solution is once again back into the capable hands of the DIY-er:


This Never Wet superhyrophobic stuff works great with clothing.

Hope that the product reaches retail soon.
jamesbrosuk6 months ago

Excellent, problem is with the battery pack

Snellingkorey7 months ago

highly practical, you couls sell a ton of these to the mountain biking and running world.

We will see, a variation has already been productized. - http://www.visijax.com/

DeanGPotts2 years ago
i love this project, but how much did all these arduino bits cost to make the project? please dont think im having a go, but when i saw it i immedietly thought this kit would work just as well using a simple oscillator circuit, using a few capacitors and resistors with a rocker switch on each handle bar, maybe $4 worth of bits.

The difference is that you can't program multiple results from the same button like in this ible. That requires some kind of small wearable computer like an arduino. Personally I'd like to see someone get a raspi hooked up with bluetooth ot wome other wireless tech to make it so there's a thing that sticks on your back or your backpack and permanently mounted buttons on the handlebars. That would be awesome.

That's a great idea dana, they could be placed on the handlebars

davidbarcomb9 months ago

What an awesome idea. Gotta try this

jason00010 months ago

Hi everyone

can anyone do this project for some $? the person doesn't reply!.

Victor Does10 months ago

Every one on a bike should have this! Nice idea!

TylerB210 months ago

Is there a reason you didn't use interrupts and sleep mode? I think it would make some of the logic simpler(of course the interrupt registration code itself would add some more lines) and reduce power consumption. You could even put the processor to sleep between LED flashing state changes and use timers, if you were really looking to reduce power consumption...

Carlo.BaCon.411 months ago

Hi! I'd just like to know its power consumption. Great project by the way!

danmellow1 year ago

super cool.. and stylish as well

ChrisW31 year ago

I love that you used the Lilypad, it adds style! :D

tnjiti2 years ago
I was not able to get the code for the behavior...can u kindly post it ?


Kelly022 years ago
nice project.
RadarTech2 years ago
Thanks for the good work. I'm using this as a blueprint for my own project.

Have you thought of using Bluetooth to remotely operate the switches?
Really cool, Nice work, Leah.

We had a guy bring something like that to our Portland chapter of DorkbotPDX meeting. He also made an LED bike polo scoreboard.

I didn't even know there WAS such a thing as bike polo!
piedrabob782 years ago
HI can I use a normal powersupply instead of the lilypad powersupply?
raptor882 years ago
you ride one handed for just that second
I think it's still better than turning my head twice or treble to check for cars. This invention could save a lot of effort and troubles.
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