Bluetooth-Enabled Bicycle Turn Signal

Resistor 221 ohm

USB-A to Micro-USB Cable

Drill

Lithium-ion power bank (or battery with 134N3P chip)

Dupont connector and some wires

Toggle switch (ON-OFF-ON SPDT)

HC-05 Bluetooth Module

Waterproof enclosure/case

Qi wireless receiver

Breadboard (generic)

8x8 LED Matrix with MAX7219 driver

Hot glue gun (generic)

Soldering iron (generic)

Arduino Nano R3

<h3 >Motivation</h3><p >After commuting to work every day on my bicycle, I decided that I needed a better way to signal my turns. Sticking my arms out can be dangerous, especially if you're riding downhill in the rain (as is common in Vancouver).</p><p >I had recently got an Arduino and wanted to embark on my first project, so I decided to kill two birds with one stone!</p><p >I wanted something waterproof that I can use in the rain, and something detachable so it wouldn't get stolen, it needed to be detachable/wireless.</p><p >The plan was to have a couple of switches embedded into the handlebars (for power and for turn signal), use a Bluetooth transmitter (HC-05) for communication, and have an Arduino Nano to control it all with an 18650 lithium-ion battery (controlled with a 134N3P chip) for power. On the other end of the bike, there are two 8x8 LED matrices controlled by MAX7219 controllers, a Bluetooth receiver (HC-05), an ATMEGA328P chip to control all the components and an 18650 (or 14500) lithium-ion battery for power. I also added a Qi wireless charging receiver to charge the battery without opening the lights enclosure.</p><p ><strong >Action shots</strong></p><p >Here's a video!</p><div class="se-component se-video-container __se__float-none" contenteditable="false" style="width: 100%;"><figure style="width: 100%; height: 56.25%; padding-bottom: 56.25%; margin: 0px;"><iframe frameborder="0" allowfullscreen="" src="https://www.youtube.com/embed/XL1OTpryOkE" data-proportion="true" data-percentage="100%,56.25%" data-size="100%,56.25%" data-align="none" style="width: 100%; height: 100%;" data-index="0" data-file-size="0" data-origin="100%,56.25%"></iframe><figcaption contenteditable="true"><div>Video of the setup in action</div></figcaption></figure></div><p >A closeup of the case with all the gubbins:</p><figure><img src=https://projects.arduinocontent.cc/c1427a9f-0754-40cf-92e0-9d628896eec6.gif /><figcaption> </figcaption></figure><p >If you don't like my boring arrows, make any indicator animation you want using my 8x8 LED byte generator found on my Github:</p><p ><a href="https://github.com/simonwongwong/LED_byte_matrix_generator">LED_byte_matrix_generator</a></p><h3 >Wiring diagrams</h3><p >Diagram for handlebar/controller:</p><figure><img src=https://projects.arduinocontent.cc/d0b7fff4-5710-4c0d-9f9b-20dafdf89415.png /><figcaption>Inside the handlebars </figcaption></figure><p >Diagram for the lights:</p><figure><img src=https://projects.arduinocontent.cc/e3d872df-b1d6-4f4e-9f56-a025c9028b0a.jpg /><figcaption>Inside the lights enclosure</figcaption></figure><h3 >Setup instructions:</h3><ul ><li ><span >Set up the HC-05 Bluetooth modules to pair with each other using a master-slave setup </span><a href="https://howtomechatronics.com/tutorials/arduino/how-to-configure-pair-two-hc-05-bluetooth-module-master-slave-commands/">(instructions)</a><span >.</span></li><li >Other Bluetooth modules with similar functionality can be used.</li><li ><span >Upload code for the </span><a href="https://github.com/simonwongwong/Bluetooth-enabled_bicycle_turn_signals/blob/master/code_for_lights.ino">lights </a><span >and the </span><a href="https://github.com/simonwongwong/Bluetooth-enabled_bicycle_turn_signals/blob/master/code_for_handlebars_controller.ino">handlebars </a><span >to the Arduino Nano (or any other ATMEGA328P based chip).</span></li><li >Wire everything up according to the wiring diagrams.</li><li >if using a reed switch to control power to the lights, you'll need a magnet.</li></ul><h3 >Variations/upgrade ideas:</h3><ul ><li ><strong >Reed switch to control power to the lights</strong><span >. If your case is too slim for a toggle switch (like my latest iteration) or you're worried about the waterproof-ness of the case, a reed switch could be used.</span></li></ul><figure><img src=https://projects.arduinocontent.cc/2b64acf9-9254-4a84-a8d0-252e5af60dfd.jpg /><figcaption> </figcaption></figure><ul ><li >A magnet attached to the light mount can turn the lights on and the lights can be turned off by taking the lights off the mount.</li><li >Or a second magnet can be used to change the flux path and open the reed switch like so: </li></ul><figure><img src=https://projects.arduinocontent.cc/4e4d3565-73c6-4272-836e-04d6ca5da6cc.gif /><figcaption> </figcaption></figure><ul ><li ><strong >Neopixel rings and jewels as a turn signal</strong><span >, like a car with the outer ring in red and the inner jewel lit up amber and flashing when turning.</span></li></ul><figure><img src=https://projects.arduinocontent.cc/90edb99f-14a2-4bed-b7f6-1eab82cd0fa2.jpg /><figcaption> </figcaption></figure><ul ><li ><strong >Add an accelerometer</strong><span > to detect slowing down and display a slowing down animation or flash amber lights.</span></li></ul><h3 >Pictures of the build:</h3><p >Internals leaking out:</p><figure><img src=https://projects.arduinocontent.cc/2122be65-3783-4a7f-8509-b758ab8b238e.jpg /><figcaption> </figcaption></figure><p ></p><figure><img src=https://projects.arduinocontent.cc/cf6e1226-80a6-4d27-baf0-42991822ed8e.png /><figcaption>Handlebar battery</figcaption></figure><p >Note: Bluetooth module, Arduino Nano and PCB separated from battery by a long ~1m cable</p><p >Testing lights before gluing everything and closing the case:</p><figure><img src=https://projects.arduinocontent.cc/7429a909-331d-4fda-a2b0-3215ab980f29.gif /><figcaption>quick test</figcaption></figure><p >It's working! Time to mount it to my bike:</p><figure><img src=https://projects.arduinocontent.cc/08e93fde-2bf3-462a-81bd-48ba75e1a423.gif /><figcaption> </figcaption></figure><p >Message me for more details if you want to make one for yourself.</p><p >Thanks for reading!</p><p >Old (thick) setup pics:</p><figure><img src=https://projects.arduinocontent.cc/e5a10d0c-6dcb-469a-8a34-9186cee5894a.png /><figcaption>Enclosure with breadboards wired up</figcaption></figure><p ></p><figure><img src=https://projects.arduinocontent.cc/82c0702a-7031-4f48-a155-05f285304ad0.png /><figcaption>Wireless charger receiver attached to battery</figcaption></figure><p ></p><figure><img src=https://projects.arduinocontent.cc/1ea3701a-1c15-4c82-b8e6-966f7dfa68a1.png /><figcaption>All parts assembled (big case setup)</figcaption></figure><p ></p>

Code for lights and handlebars

Wiring diagrams

Bluetooth-Enabled Bicycle Turn Signal

Are you tired of sticking your arms out to indicate which direction you're turning?