Arduino RPM Light / Shift Light

Guide for a DIY Arduino powered shift light with code and CAD files for housing.

Parts list is as follows;

Arduino nano
70mm x 30mm double sided Prototype PCB
1x 330 ohm resistor
1x 47 kohm resistor
1x 10 kohm resistor
1x 5v reg #7805
1x heatsink #V4330N (fits perfectly to the board and voltage reg)
1x PNP transistor #2N3906
1x 1000uF (min 6v) capacitor
2x neopixel 8LED strips #WS2812

The circuit needs to be built as pictured;

It should be assembled on the prototype board as pictured;



The circuit board can be connected to the car by splicing into the wires behind the OBD connector:

The Arduino needs to be programmed. The appropriate software can be found here:

The code and stl files can be found here:

Here are some photos of the finished product:

Some video:


Super super cool! awesome job!

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You thinking of doing s few to sell? Love the idea but don’t have the tech or time to do it all anymore. Plus the eyesights terrible a close range, too often staring a light from a weld with a bucket on my head.

interested if you would produce them.
I assume you need to program the rev range, no way of putting a potentiometer or dip switches to change the setting?


I would be happy to make them and sell them, I would say about €50 for a finished piece. However I have posted all the plans online for free so people can make their own for about half that.

There are other plans and kits available online with buttons and dials to make adjustments, but the idea of this project was to do away with all that.

Also for the DIYers I have added instructions in the code, so it should be very easy to set up for different engines and shift points.

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thanks for the info, I would have done it myself years ago, but I haven’t even got a soldering iron anymore, and am happy to pay for assembly and testing :smiley:

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Sneak peak at the new design with a gear position indicator.

It will be a 50x70mm 16 segment LED display mounted on the dash. The complete electronics fits on a board the same size and will be inside the display case with connectors in the back for gear position input, Tacho input, output for the shift light.

Gear position will be measured with 2 potentiometers on the gearstick to measure x and y axis, similar to a joystick.

A lot of time has gone into it, it’s far from finished but I will keep you all updated.


Hi Mick,
can you please upload the Code again?

Also an Idea for an Update: I use an Arduino for a Board-Computer System (4x DS18B20 for Oil, Water and outer and inner temperature and a VDO Sensor for the Oil pressure.

I will make a GitHub repo tonight so it’s permanently available.

Updated original post with link to GitHub repo

couldn’t do the shiftier with a hall effect sensor and a magnet on the shift lever?
Should have a different reading in each position if you mount it 45’.

You would need 4-6 hall sensors depending on how you set it up. Impossible with only one. Plus, mechanically speaking, doing that way would be a massive headache on a dai as the shifter goes through the floor. My way seems more complicated, but it’s actually simpler, requires less wires, and works.
Here’s some more info:


Made it last week and it works :partying_face:
Thanks Mick!

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Make sure you fit a heat sink to the 7805, they get very hot otherwise.

Great work :+1::+1::+1::+1:

Also if you’re using my code you can set up the led colors however you want, feel free to ask if you need any help with it.

I have the heatsink, just haven’t mounted it yet.
I like the colors for now, maybe i’ll change them later.
Now i just need to make a bracket or use your printed bracket to mount the leds.

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Hello Mick.
At First, nice Project!
I´m trying to make it working on a 1 cylinder 2 stroke engine and with only 8 LED´s
I´ve also change the frequenz and 8 LED´s in the code.
To calculate the Frequenz for 1 cylinder 2 stroke i use the RPM divided with 16,667. Do you agree?

Just see in the code a startup sequenz. Do you have a video from it, how it should look.
In my case, also with your standard code, the first two LEDs are all the time on when power up.

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Edit: i’ve got 51mm strips instead of 56mm

@Mick Where did you order your led strips?
The ones i’ve ordered at reichelt seem to be a little short so the led’s don’t match with the holes.

Sorry for the late reply, I will have to take a look but I think they came from Amazon

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are you still planning on producing and selling these yourself? I’m very interested

I am considering doing a small run. Since the same circuit is included in my gear indicator circuit board, I would probably just sell that and you could just populate the shift light part of the board.

I have not been very active here as it’s winter and I have been preoccupied with my latest project, a Touch Screen tire temperature data logger with a built in thermal camera:

If you have GitHub you could contact me there, I am more active there during winter time. I will be open sourcing the gear indicator schematics soon. These projects are designed to be open source, I can make you something for sure, but it’s not my goal. I post this stuff for people to have fun making it themselves.

This is the circuit board for the gear indicator. It’s quite compact, just add a few resistors, a transistor, reg, and a nano and you’re good to go. If you’re feeling adventurous you could add the other stuff too and have a gear indicator on the same device.

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