Picture of Bike Turn Signal & Brake Light Handlebars
This project was inspired by a very cool kickstarter called Helios Bars. Essentially what this project does, is put an arduino, LEDs, and buttons into your bike handlebars. The LEDs can be used as turn signals, brake lights, or display ambient colors while riding. It's fun, cheap, and a good introductory to LEDs and arduino. The coolest thing though is that the project can be completely enclosed in the handlebars and even waterproofed! This is because the Arduino Micro will fit inside handlebars with an inner diameter of 0.7 inches or greater! It is also a cheap project with a cost of around $30-$40 to buy everything. The best way I can explain it is by showing it, SO CHECK IT OUT BELOW!

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Step 1: Parts List

Picture of Parts List
To modify your handlebars this project uses a 'kit', all the pieces of which can be bought at a place like Radioshack. It's a fairly simple and cheap project, with few components.

Arduino Micro - You could also use Arduino Uno or any others, but they would have to be externally mounted to the bike. If you have a choice, get the version of the Micro without headers.
2x Pushbuttons - I used 12mm ones seen in the picture, and they work awesome.
2x RGB LED's - These need to be common anode to work with my code. I recommend 2, but the number is up to you. You should probably get more just in case.
Resistors - These are needed for the pushbuttons and the RGB LED's, so they will be specific to what you use. I used four 2k ohm resistors. 
Batteries - Anything 6V or greater works but I will discuss this a lot more in the 'Custom Battery' step.
Wire - Lots and preferably thin and flexible.

Soldering Iron
Metal Files

Additionally if you want to waterproof the bars be sure to get some sugru. More on this in Step 7.
markgrecowork2 months ago

Mizchief, wondering if you thought adding an automatic on off type of sensor? I have been using my rig for 4 months or so and I have to unplug each time I'm done. Wouldn't it be great with 5 minutes of inactivity it turns off and a touch of the button (right or left ) it turns back on? I'm using a micro exactly as you have it.

Philanthrop5 months ago

can you upload the wordfile for the arduino again, i cant find it

markgrecowork made it!10 months ago

I Made It !!!!

I will be adding limit switches in the brake levers.


Mizchief100 (author)  markgrecowork10 months ago

Awesome! Post a pic of the finished product, I'd really like to see it!

markgrecowork10 months ago
Thanks for your reply the difference is is that I ride a cargo bike, it looks like you are a fixie rider. Sometimes it's difficult to remove your thumbs from the grips. I could incorporate microswitches into both the front and rear brake levers. I have my prototype breadboard complete and it works flawlessly pressing both buttons. As I said I can follow directions but the programming is beyond my skill set.
Mizchief100 (author)  markgrecowork10 months ago

Ok yeah I didn't quite understand what you were getting at before. If you want to have buttons in the grips and in the brake levers you could wire them in parallel (have all the same wires go to both buttons) and then when either is pressed it will work like normal. Or of course you can just put them in the brake levers if that's easiest.

markgrecowork10 months ago

Would you be willing to add code to actually have RED brake lights? I would connect a micro switch to the brake lever

I can follow directions but writing code is beyond my skill set.

Mizchief100 (author)  markgrecowork10 months ago

Right now in the code if you click both turn signals at once it holds RED brake lights for four seconds.

Bravo for your project.. It is really awesome and pretty useful.

I am looking forward to start next week creating your project. I have only 1 question.

Is it ok if I select Arduino Pro Micro or Arduino Nano?

Mondonson1 year ago
Helios here we come!
I think that on flat bats like for a mountain bike you could mount it like this but put a couple of ping pong ball halves for light dispersion on the ends and just got glue them on the ends. Maybe fill them with the hot glue for even better light dispersion. That way it could be seen from the front, side, or rear of the bike.
Mizchief100 (author)  Dana LaBerge1 year ago
That'd be sweet! Try it out.
drascombe1 year ago
While it seems like a good idea, is it really useful? I mean a car has its turn signals lights about 6 feet apart with following cars directly behind it. With a bike, it is a bit different. At most those are 18 inches apart, and from 40 feet away in the dark, can you really tell whether it is signalling left or right? Maybe it should be more light boat running lights where port is red and starboard is green?
Mizchief100 (author)  drascombe1 year ago
In the dark they are visible from much further than 40 feet. After doing this instructable I actually flipped them over so they point out to the front now and use a blinking light in the back so there is no problem with them being blocked by my legs or body. Most importantly though, it is meant to be a fun project and not to solve every bike visibility problem.
That is a great idea
pweintraub1 year ago
Yes! Thank you! Bikers need to be seen!!
Gorgus1 year ago
When trying to downkoad your code I just get: 403 Forbidden Request forbidden by administrative rules.
Mizchief100 (author)  Gorgus1 year ago
Thanks for letting me know, I will re-upload it shortly!
Mizchief100 (author)  Mizchief1001 year ago
Just out of curiosity can you propose ways this might work with flat bars? Thanks so much and what an awesome tutorial!
It can definitely work with flat bars! The only thing slightly different would be LED placement, since they would point out to the side rather than straight front/back. You could just drill a hole in the bars near the end caps (rather than in the end caps) to fit the LEDs if you wanted them to point forward/backward, but the LEDs pointing to the side shouldn't be a problem. If you have any other questions feel free to message me.
this is awesome!
thumbs up for the great italian brand bike frame! ;-)
Mizchief100 (author)  andrea biffi1 year ago
Thanks, and yeah I love my Bottecchia!
rzprk1 year ago
hey. i see you put a lot of efford into this and agree that this is a great introduction to attaching electronics to otherwise analog devices. just some final touch ideas.
if you can sacrifice function over aesthetics, i'd recommend to feed an dc-plug out of the handlebar somewhere in the center, preferrebly glued into it entirely. this way, you could use a 9v battery velcroed to the upper tube when needed for power supply.
behaviour: I suppose you arranged the buttons in a fashion you would press the right one for going left and vice versa, so you'd still be able to use your arms for indicating direction.
sensorics: acc- & deceleration: a 3axis accelerometer could be a fun way to strobe the leds if decelerating rapidly. i dunno wheter there are pressuresenstive stripes, if existing, theyd be a great thing to be put underneath the grip so you'd just have to grab harder...
Mizchief100 (author)  rzprk1 year ago
Hey, thanks for the ideas! What I did to mount my 9V outside was cut a small notch in the handlebar plug and feed out the V-in and Ground wires to plug the battery into, but you could attach these to a dc-plug it would just be a little less universal. I thought about using an IMU because I've got one that would fit in the bars, but you gain very little, it about doubles the cost, and makes putting it into the bars more challenging but to take this project to another level it would definitely be worth it! I also tried to just use common electronic items people could find at electronics stores, but pressure sensitive strips would be cool for sure.