Functional LED Number/Position Display

6084 Views 62 Replies 8 Participants Last post by Drifter2, Nov 15, 2021

Flag Slot Racer

Discussion Starter · Aug 6, 2021

2

I'm adding an array of lights to my Audi R8 that I have recently re-liveried. For that project, I added an Arduino mini so I could easily add exhaust flame lighting and I had it laying around anyway. Then I thought, while I was at it, I might as well add a seven segment display for displaying race position (funny how these things snowball

). So I spent a lot of time searching around for some seven segment LEDs that might be small enough to be to scale. Here is what I was looking to recreate...

So this was the closest I was able to find...

Not perfect, the text size is okay, but I would prefer something with a smaller base footprint. The LED is red, I would prefer white, but I will take red.

Anyway, I did have this on my Exhaust Flames thread, and was to start a new thread for this by Tamar.

I was originally thinking that this would be cool to hook up to the RMS to tell position as the 1:1 scale versions do, but I also think this could be great for just displaying the car number ( this would not require hooking it up to a micro controller). As Tamar pointed out, it's very difficult to figure out which car is which in a night race, so this could help out greatly.

Next step is to solder up the wires and hook it up to the Arduino mini.

Thanks for reading.

Heath

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GRUNZ

· #2 · Aug 6, 2021

Very good find Heath. I admire your ingenuity.
Yes, having something like that would be really great.
There is so much untapped potential in digital systems for slotcars.
Taking inspiration from railroad modelling, there is definitely more functionality that needs to be implemented to make racing more realistic.
I am not talking about sounds because the speed at which slotcars travel around the track would make it not prototypical.
But having more realistic lighting system integrated with the RMS is definitely something that can be done.
And it should be done because like in the 1:1 racing, it will help with digital racing as well.
Some example:

Flashing lights when car enters pit lane
central rear red light (flashing) when track wet or when in track call/yellow flag (controllable and programmable via the RMS)
Position lights (controlled by the RMS)
flashing high beams (for annoying the car in front of you!) controllable via dedicated button on the controller

These are just some quick ideas.
I am sure that if we would brainstorm we could come up with more all of them doable with today tech.

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Dr_C

· #3 · Aug 6, 2021

This one is white… is it the same size?

I too admire your creative thinking

c

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Flag Slot Racer

Discussion Starter · #4 · Aug 6, 2021

Thank you both for your kind words.

Gio, I agree. There is much that could be done for digital lighting. The missing element is the RMS support, it seems that may be solved with Scorpius, based on the topic they just started

Dr C - a .2" size might be better in terms of the base, and I'm loving the white. Do you have a link for that?

Heath

tamar.nelwan

· #5 · Aug 6, 2021

Heath , thanks for splitting up the topic, Clive looks like your find is a bit smaller than Heath's
The 0,2 inch would be 6.9x10x3.8 mm...pretty close to what's needed
link

To create a set of these digital number displays for lets say an Oxigen GT3 endurance race.. you could skip the Arduino. We would just need a pcb to mount the display with the proper pins connected to do 0-9. With 20 ID's we would need to do double digits.

With kind regards
Tamar

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Discussion Starter · #6 · Aug 7, 2021

I agree that is a great size. Unfortunately it's a 100 min order at a $1.50 a piece. Can't seem to find it anywhere else.

Heath

Dr_C

· #7 · Aug 7, 2021

Am I right in thinking there are two options here - either displaying a static number for the car (i think that is what Tamar is looking for for night time car IDing) while Heath is also thinking the car could display its current leader board ranking? If so would this be as per the last S/F line transit?

Exciting stuff!

c

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Dr_C

· #8 · Aug 7, 2021

I really like the idea of car info on a small display on the front windscreen… very cool… and we must do it!!!! however with cars travelling at 7-8m/s in the dark, a 5mm tall LED digital read-out is going to be very hard to clock with human eyes (I suspect) so how about:

1/ the cool front windscreen read-out for authenticity… and…

2/ the headlights strobe the car ID… so a marshall with suitably enabled equipment sees the car ID number dispayed… either track-side or via augmented reality glasses.

We could strobe the headlights with the 14 car ID I have been working on… or even extend it to 32 car IDs no problem. The headlights would then strobe the car ID… for the benefit of both the night-time race marshalls… and the spectators too…

c

If the idea works… lets use it… who cares who invented it… anyway I think its a copy of how aircraft identify each other in the darkness of the sky…

Dr_C

· #9 · Aug 7, 2021

The above would work equally well with 14 car mark/space ratio IDs, 32 car mark-space ratio IDs and of course UART coding… of the headlight strobe.

And, one slight detail… if using the mark-space ratio as per SSD… the atrobe should be inverted for each alternate pulse so that cars show the same headlight brightness regardless of ID… ok?

c

tamar.nelwan

· #10 · Aug 7, 2021

Flag Slot Racer said:
I agree that is a great size. Unfortunately it's a 100 min order at a $1.50 a piece. Can't seem to find it anywhere else.

Standard procedure in such cases would be to contact the seller...and ask for a sample 😇
There's a Dutch saying: "Nee heb je, Ja kan je krijgen" Freelay translated as " No is a given, yes might be obtainable"

Should this work out, a full set of ID displays for an Oxigen Endurance race organizer like me would require 40 units (ID's in double digits range 01 - 20)
So if "no" for a sample will be the final answer from the supplier... maybe a bit of 1/32 scale crowd funding could help out.

Dr_C said:
Am I right in thinking there are two options here - either displaying a static number for the car (i think that is what Tamar is looking for for night time car IDing) while Heath is also thinking the car could display its current leader board ranking? If so would this be as per the last S/F line transit?

Obviously displaying "just" the car's ID nr would be easiest as this would require only "dumb" hardware, all number combinations being pre wired, requiring "only" a piece of cable and connectors to be fitted in the car.
For the "smart" option you would need something to control/program the display (Arduino or dedicated chip).
3 instead of 2 displays would be better here..maybe something like this Link
You could have a sequence where the display would show Car ID alternating with a 3 digit abbreviation of the drivers name.

An interactive option including race position would require:

something to receive information from the RMS
something to control/program the display

With kind regards
Tamar

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tamar.nelwan

· #11 · Aug 7, 2021

@Clive
About Marshall's and counting. I think you underestimate the ability of a race director to read the display...and overestimate the ability of the marshals to keep track of the number of strobes of the headlights

Dr_C

· #12 · Aug 7, 2021

www.slotforum.com

Functional LED Number/Position Display

I'm adding an array of lights to my Audi R8 that I have recently re-liveried. For that project, I added an Arduino mini so I could easily add exhaust flame lighting and I had it laying around anyway. Then I thought, while I was at it, I might as well add a seven segment display for displaying...

www.slotforum.com

www.slotforum.com

If ordering any… go for the common anode version… then hardware based on the ULN2003 can be used… which is straight forward.

c

Dr_C

· #13 · Aug 7, 2021 (Edited)

tamar.nelwan said:
@Clive
About Marshall's and counting. I think you underestimate the ability of a race director to read the display...and overestimate the ability of the marshals to keep track of the number of strobes of the headlights

Maybe! and very happy to be proven wrong…

Reading a 5mm high LED screen moving at 7m/s is likely beyond the resolution limits of my not-so-young eyes… but others will for sure have better night vision capabilities… the strobe would need some electronics to assist any homosapien retinas … but if required… so be it.

c

Flag Slot Racer

Discussion Starter · #14 · Aug 7, 2021

I'm hoping to hook it up later today. Then we will see how easy it is to read. I won't be able to get the track down until next weekend, but I can do some test runs with a rolling chassis.

Heath

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GRUNZ

· #15 · Aug 7, 2021

the slot.it Chip C has 6 pins for the light circuit. Maybe something smarter could be done there.
Maybe they are not enough for display the current position for the entire field, but at least we could have the first 3 positions.

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Flag Slot Racer

Discussion Starter · #16 · Aug 8, 2021

Finally got the display hooked up. I had to add some electrician's tape to the back to prevent light bleed...

I think the visibility is really good up to about 8ft away. As it gets darker, it gets easier to read. This will be hooked up to the Arduino Mini, but it would not need to be to have just a static number. If you wanted to push the realism a bit, you could go with a larger display, which would be readable at a greater distance.

So far, pretty happy with the way it is turning out.

Heath

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GRUNZ

· #17 · Aug 8, 2021

I personally would not care about the readability during the actual race.
For me, flashing would be enough to identify the race leader.

Anyway, looks really good Heath.

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Flag Slot Racer

Discussion Starter · #18 · Aug 24, 2021

Finally got the wires soldered to the chip (along with the rest of the lights). Now I'm ready to attach the LED display to the window. I'm thinking E6000 glue, but does anyone have a better idea?

Heath

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GRUNZ

· #19 · Aug 24, 2021

I am not sure about the E6000, but GS-Hypo is my choice when I have to do glue leds and transparent parts: it hardens clear and it is easy to remove in case you make mistake.
It is also very flexible so I actually use it for all my builds

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Flag Slot Racer

Discussion Starter · #20 · Aug 26, 2021

After much soldering, head scratching, and trial and error, the wiring is now all hooked up…

I also managed to program the Arduino mini to light up the number.

Thanks for the tip Gio.I’ll have to pick up some GS-Hypo.

Heath

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