Wireless Motorcycle/bicycle Helmet Brake Light ..very Easy





Introduction: Wireless Motorcycle/bicycle Helmet Brake Light ..very Easy

About: I'm in college and have a profound interest in robots.

Hello everyone,

the main idea of this project is when i hit the motorcycle brake lever the led lights on the helmet or jacket light up making the rider more visible and hence safer on the streets.I didnt want the wires all dangling from the bike to the helmet so i made a wireless module.

Step 1: Things Required


>battery(i used a lithium ion 3.7V battery

>433 mhz rx

>433 mhz tx

>7805(voltage regulator)


>opamp 741

>transistor bc547

Step 2: Tranmitter Part

connect the circuit as shown above.

we are making use of 433mhz rf module for the wireless communication.first assemble the circuit on a breadboard make sure everything works fine and then proceed to soldering. The transmitter of the 433 mhz module will have 4 pins as shown in the figure. namely ground , data , vcc, antenna.since we are using it on a motorcycle take the wire out from the motorcycle which goes to the rear brake light and attach it to the input side of the ic 7805 we are going to use the output of the ic as both a power source as well as a data signal, therefore connect the output of ic7805 to both vcc and data pin on 433 mhz Tx. Now ground both the the ic7805 and rf module .the antenna can be made of a wire 17.3 cm long.

The tranmitter part is done


Step 3: Reciever Part

The reciever part has four components

>the rf Rx module

>the opamp ic 741

>transistor bc547

we use the 433 MHz Rx to recieve the transmitted signal .When a logic 1 is transmitted we recieve a logic 1 but when we send logic 0 we expect a logic 0 but that is not the case we get some voltage around 2 volts therefore we use a opmap ic as comparator and clamp down the recieved logic zero voltage to 0V. now the output of the opamp ic is does not provide enough current to drive the relay therefore we use a transistor acting like a switch. When the base current is zero the transistor acts like a open switch and does not let current ic to flow.When the base current is provided the transistor acts like a closed switch and provides a path for current ic to flow. The base of the transistor is connected to the output of the opamp circuit .the emitter is grounded and the collector is connected to the relay as a load. The relay acts as a switching network to drive bigger lamps or lights as per your wish.

Step 4: Test Your Circuit and Have Fun.

attach leds on the helmet or attach them on the jacket as per your liking. be safe on the road .cheers.
disclaimer- make sure its legal in your country to put up such lights .



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    I notice it looks like a 1k resistor between pins 2 and 7 on the LM714. However, the resistor isn't listed in the parts list. Is it needed or not?

    Could you also include more pictures? Like how the soldering was done(other side of the pcb) etc? Thanks.

    how did you fit the receiver in the helmet without it breaking? Can any of the components in the receiver be replaced with smaller components ?

    How do you connect it to the motorcycle?

    that is totally fine ..even i am using only 4 pins the only difference between your module nd mine is tat i have extra ground nd vcc pins ...no need to worry just wire it up as per the circuit diagram Nd you will be fine


    Indeed a Good and simple project !! My question how Tx and Rx can be paired so that the Tx from one rider can not impact the Rx on the Other Rider. I mean if Rider 1 use Brakes light of the other rider should not light up.

    Indeed a Good and simple project !! My question how Tx and Rx can be paired so that the Tx from one rider can not impact the Rx on the Other Rider. I mean if Rider 1 use Brakes light of the other rider should not light up.

    hi..friend..the 433 mhz i bought was only have 4 leg..can u teach me how to connect??ur gelp much appreciate.


    I stay in Goa (India)....like ur helmet stuff dude awesome...we bikers will get it up & on....we r a biker group called Hogs of Goa....All of our 28 members with Harleys....this fr the heads up...cause we r really fast on cross state trips...cheers

    1 reply

    thanks peter for watching i will be really happy if u guys make it ...pls do send a picture if u ever do make it cheers...ride hard ride safe

    In your title you have bicycle but in the instructions you satori patch into the brake switch on the motor bike; how does this work for a bicycle

    1 reply

    for a bicycle just add a switch between vcc and data pin on the transmitter side .

    very nice and safety improving!

    I think, this is a very cool idea. Though you might consider to add a disclaimer. Here in Germany the street driving laws are very strict (and often a bit ridiculous). So using such a device might be illegal (I said ridiculous, didn't I?). I'm not sure whether that proves true (I'm neither a lawyer not a police man). But one should check this before ruining its day.

    1 reply

    thanks for the headsup but i stay in india and no such traffic law exists here that prohibits the use of such a device , thanks for the advice i will put up the disclaimer