In a software management class, we were asked to design an application using softwares of course. So we thought of doing this turn signalling device prototype controlled by a microcontroller via an Android phone's bluetooth connection.
Step 1: Creating the Hardware, Firmware, and the Software...
The design was made in EAGLE CAD and was based on Microchip's PIC18F4550 microcontroller. Only a few pins were used for I/Os, an HC-06 bluetooth module to communicate with the phone, an array of LEDs formed into arrows which would point to the right and to the left, and a USB connection for flashing via an HID bootloader. Don't forget to add an external switch since this would be placed inside an enclosure.
The hardware C file was originally written in an Arduino sketch and then later on converted by definitions. Majority of the program are "if" conditions that would blink the LEDs depending on what you have tapped on the phone's GUI. It could point to the left, to the right, or both indicating a hazard.
The UI was developed using Android Studio. It is a minimal design that only has three images. The images would also appear blinking when it is tapped. The second time you tap the image, the LEDs would be in idle (all lit up and not blinking).
I've attached all the resource files below for you to use. If ever I might have uploaded the wrong revision or if you have a question, you can put a comment below :-)
Step 2: Put Your Helmet on and Take It for a Spin...
Install the app first on your android phone by executing the .apk file. In order for your phone and the device to communicate, you have to pair them on the bluetooth settings. Now by default, the name of the device is HC-06 (the bluetooth module's model). The app would also ask on which paired devices it should connect to. Then if it has properly established a secured connection, you should see a status on the app saying it is connected and then you could now control the turn signal. If it fails to connect, probably due to a delay, just repeat on selecting a paired bluetooth device. It won't take more than two times to get you connected.
And viola!!! You have made yourself a turn signalling device. And if you are really planning to deploy this on your bike, just don't forget to remove your phone's timeout lockscreen. It would ironically defeat the purpose of advocating road safety.