This project was inspired by the work of Kenji Ganakuto on YouTube.
He has actually cut the light unit with an ultrasonic cutter, to install LEDs there, which is quite a complicated process.
I decided to design a simple bulb replacement instead. After taking a closer look at the light unit design, I found that I can fit there a 4″ long LED light to produce a similar effect.
I did a quick 3D design and printed a plastic mockup, to verify the shape of future bulb replacement with 36 (3×12) LEDs.
This fits perfectly inside the available space. The next step is the electrical design. I found NXP 12 stage shift register to control LEDs, and PIC microprocessor to control the shift register. I chose high power OSRAM yellow LEDs because I had experience with this brand before and they seem very reliable. The original bulb rated 500 lumens The new LED light will produce about 720 lumens (about 20 lumens per LED) when all 36 lights light up.
My PCB has white masking, to make it less noticeable inside the unit, and a 3D printed T20 plug and a support clip.
The next video shows PCB installed inside the light unit. Unfortunately, the lens and mirror inside this unit reduce the sequential effect.
The LEDs are super bright. For this video I dropped the power twice, otherwise, it is hurting my eyes. I think the number of LEDs can be reduced to 24.
I installed my lights today. Using Mazda instruction, it took about 30 minutes from start to finish. I think it looks great!
I created my Installation instruction as well.
modified sequence example:
About ballast resistors
For North American cars ballast resistors are not necessary if front bulbs are 27W.
For cars, where the front bulbs are 21W, like in Europe and Asia, 24 Ohm 10W ballast resistors are necessary to avoid hyper flashing issues. A ballast resistor must be installed between wires going to the bulb socket. For plug-n-play installation, I have premade a harness with such a resistor.