Introduction: DIY Bicycle Indicator Lights
The bicycle indicator light is a wearable device that is most suitable for use when riding at night time. The device can indicate which direction the rider is about to turn. The device also enables the vehicles behind the rider to be aware of the rider's presence.
Supplies
Hardware:
- Velcro
- LED pack
- PIC16F18313
- Resistor Pack
- MPLAB Snap programmer and debugger
- 3D Printer
- Bantam Othermill Pro (or just any other CNC PCB machine)
- Copper clad board
- Stripboards
- Pin headers
- 2N2222 transistor
- Connecting wires
- Heat shrink tubes
- SPST switches (2)
- Toggle switches (2)
- 400mAH lipo battery and charger
- Superglue
- Sandpaper
Software:
- MPLAB X IDE
- MPLAB X IPE
- KiCad
- Fusion 360
- Bantam Tools Desktop
Step 1: Draw Circuit Schematic and Prototype on Breadboard
Begin by drawing out the circuit schematic in KiCad or any other CAD software you are comfortable with. In my case, I decided to select the PIC16F18313 as the microcontroller unit (MCU) for this project because it has the minimum number of pins required and it also has some additional advanced low-power features. The other parts of the circuit were designed around this MCU.
After drawing out the schematic, prototype the design on a breadboard to ensure everything is working as desired. Once everything is working fine, move on to the next step. This is where the MPLAB Snap programmer and debugger, MPLAB X IDE, and MPLAB X IPE come into the picture. If you are using a different MCU, you may need a
Step 2: Design and Mill the Printed Circuit Board (Optional)
Import the schematic design into a PCB routing software (KiCad installation comes with both a schematic designer as well as a PCB designer).
If you are going to be using a CNC milling machine, ensure to adjust trace width, hole sizes, and via sizes to match the minimum specifications of your machine. In my case, I used the Bantam Othermill Pro to fabricate the PCB. Also, I used the 1/32" flat end mill bit to make the PCB because I wanted the process to be quick. Selecting a smaller tool would have taken a longer time to fabricate; although the result would have been finer and the minimum specifications would have also been smaller.
Another alternative to this is to just use strip boards. The advantage of the milling method over this is the repeatability i.e. You can make tens of the PCB faster using the milling machine.
All in all, just go with the most attractive and most affordable option for you.
Step 3: Solder Components to the PCB and Test
Once the PCB is ready, begin to solder all the various parts to the board. Ensure to take note of not soldering components that would need to be connected to some parts of the casing directly on the PCB such as power switches and the toggle switches in this case.
After soldering all the components in place, power the board and ensure things are working as designed. If for any reason something is not working, then it is time to enter debugging mode.
Step 4: Design Enclosure in Fusion 360
The various parts of the enclosure were designed in Fusion 360: housing for electronics and cover, toggle switch enclosure, and velcro attachments.
Several prints were made before finally arriving at a suitable design for all the different parts.
The velcro attachments were also glued to the housing for electronics and the toggle switch enclosure (using superglue) as shown in the images. The locations where the glue was applied were sanded before applying the glue.
FIND ATTACHED MY ENCLOSURE DESIGNS.
Step 5: Assemble Electronics and 3D Prints
Now that all the parts are ready, insert the electronic parts into their various housing.
Also, put the velcro straps in their destinations.
Step 6: Perform Final Tests and Trials
Now that everything is in place, test your final design and enjoy your final product.