Replica DeLorean Time Machine Time Circuits

Hi everyone,
I'm thinking about building a replica of the Back to the Future DeLorean Time Circuits. It consists of 15 alphanumeric/seven segment displays, 10 additional LEDs, and 10 buttons for keying in dates/times. I've done smaller Arduino projects before, I dont believe coding will be a difficulty, however I'm unsure how to approach the project from the hardware side. In what ways can I controll the nearly 350 LED segments (+ 10 additional) and while still being able to utilize the buttons and sound effects as well. (Will I need external storage for those?


(This will be going in my 1981 DeLorean along with some of my other replica props.)

Use i2c connections on the lcd displays (only two pins) and for the LEDs they sell 5mm addressable LEDs which only require 1 or 2 pins for many thousands of LEDs

Sadly the only displays sold by Adafruit are only four digit. I also need three and two digit displays.
Are there boards that allow me to use my own LEDs and address them through i2c? How many i2c connections can I have on a single Arduino?

Ebay has them, but it is difficult to find alpha numeric displays that come in 3 per unit. Your best bet is to get a double and manually wire a single next to it or just do all of them manually. I have a difficult time trying to find the drivers for the alpha numeric displays as it is.

However, instead of going crazy finding all the pieces yourself, you could just buy a complete kit online and build that. It might not have the same satisfaction as finding them yourself but at least you'll get to keep your hair longer.

I've found the exact displays I want. (From Knight bright) However I need some way to control them. Are there i2c boards capable of controlling any type of LED? How many i2c devices can I use at once?

I havent seen any kits available.
Screen accuracy is a must!


there are i2c backpacks that you can attach to any display.

Correct me if wrong, but those are for connecting to LCD displays. The time circuits uses 7 segment and 16 segment LED displays. I need some way to controll every segment individually. It is 300+ individual LED segments.

it appears that those can drive 128 segments from a singe chip... so you would three of them.

Use i2c connections on the lcd displays (only two pins) and for the LEDs they sell 5mm addressable LEDs which only require 1 or 2 pins for many thousands of LEDs

Great Scott! DeLorean-Inspired Time Circuit Clock with Adafruit gear! « Adafruit Industries – Makers, hackers, artists, designers and engineers!


Also use the search facility at the top RH corner of this page and search for delorean

Tom... :slight_smile:

I'm having difficulty finding the 7 segment and alphanumeric displays in common cathode. Does anyone know a source for those in .56 inch, or a good method of using common anode with the HT16K33?


Search for "MAX7219 7-segment" on ebay.
Those cheap chainable 8-digit modules use the much faster SPI bus.
And the same chip can drive 64 individual LEDs.

Those would be a good alternative however I need three two digit sections, one four digit section, and a one three digit alphanumeric section. I also did not see any yellow ones for sale.

Lumex 0.8" 16 seg green

Lumex 0.8" 16 seg Red

Lumex 0.8" 16 seg Amber Yikes 10,000 min order!?!

Finding a set of matching size & colour in one colour is going to be difficult. 3 different colours much harder. Good luck! You must learn to use the product selection pages on major retailer's websites like

I think 3 x ht16k33 modules, as already suggested, would be your best bet. This will mean use of common cathode displays, making finding the right ones even more difficult. Each module could drive a row of 3 14/16-seg displays plus 10 7-seg displays. If you can find 14-seg as opposed to 16-seg, you can sneak 6 extra leds in there.


Search here

Did you search the forum for delorean ? ? ?

Tom.... :slight_smile:

Hi there, sorry for reliving an old post but im trying to make the same prop

I already did some digging and bought 10 1 bit 7 segment displays in red and 3 HT16K33 chips to handle them (1 for each time row)

My idea is to first start making the PCB of the RED layer and for now only the 7 segment (still haven´t decided if I’ll use alphanumeric for the month display)

However looking at the datasheet of the HT16K33 is still confusing to me how to wire them up

Here is a diagram I´ve found online

That's not a diagram. That's a photograph.

So, you can't find a schematic showing how to wire 7-seg displays to an ht16k33? Tried Google?

Sorry I was searching for my diagram and found the picture, which is exactly at the moment what I want to accomplish, (with arduino uno and 10 7 segment displays.)

I found the datasheet for the HT16K33, and some documentation on adafruit.

Here is the diagram that I think it comes closer to my needs

From what I deduced (which is not much given my amateur knowledge) The chip has ROW0 to ROW15, which are 16 anode connections

Then, from COM0 to COM7, 8 cathode connections.

My lcd displays are common cathode

I saw that the HT16K33 can drive 128 leds, or 128 7 segment bars, since I have 10 bit of 7 segments, I have 70 combinations (this is my type-reasoning)

In the diagram they use ROW3 to ROW10 to drive the 7 segment (plus DP) and then use ROW11 to ROW 15 as additional cathode connections (to add 5 bits? to the already supported 8? given 13 bits 7 segment display?)

Is this correct?

Also, I don´t understand the three 47k resistors that are used in the COM0, is this for the keypad reading ?(which by the moment I would not use)

Thanks and sorry for the clumsiness

Quick update, I found the 47k resistors use, they are for the I2C address contacts