Create Multi-Screen Gauges for Your Car using LVGL

[@hspetrolhead863]

I like the track mode ❤❤❤

[@GarageTinkering]

We'll get some in the EP3 soon!!

[@hspetrolhead863]

@ 😮😮😮

[@fredthebulldog529]

You should do a splash screen on startup. I'm building a custom system for work that when it starts up, the company logo fades in, fades out, then the background color fades into the main display. It's pretty quick, a couple of seconds but it also allows for metrics to be pulled from different peripheral systems so the display is ready to go with values when the splash screen is done. For you, putting a 300z logo that appears on startup and then fades out into your meters might be interesting. Another idea is if you have a critical value like water temperature is above a certain amount or oil pressure is above or below a certain amount (would need to have a check time offset for low oil pressure to account for initial engine start while pressure builds), having it switched to a screen showing a large alert icon in red indicating what the problem is. Just a quick transition to the alert and then transition back just to grab your attention

[@GarageTinkering]

Splash screens are already in progress but taking time as I'm being stupidly ambitious lol. More on that soon :D

[@DrFiero]

Just thinking out loud but... might be cool if you did a ++/-- loop at boot that ran the "needles" from zero to full scale and back! Give it that analog look & feel.

[@GarageTinkering]

I'm literally sat here writing a boot animation as we speak. Be gone from my brain, devil

[@DrFiero]

@@GarageTinkering - 😈 😁

[@DrFiero]

@@GarageTinkering - oh yeah, I just semi-timed my gauges. Whole event should be done in no more than 2 seconds to make it not annoying.

[@soyo]

That's a Fueltech's Nano PRO DIY version, nice project!

[@Crusher9mil]

Super cool project and thanks for sharing. In track mode tire pressure would be an important bit of info. I'm sure if you're actually at the track you'd certainly check every tires pressure but what if you pick up a puncher. Maybe add an icon that's only visible if you're getting a low tire pressure from your canbus. You could create 4 icons all the same but a small number 1-4 on the upper right side, e.g. (LTp¹) (LTp³)

[@GarageTinkering]

Honestly, if my car had TPMS on the CAN it would have been there now, but it doesn't. Down the line I'll be adding a custom system for it though, and at that point it'll be getting added for sure

[@Crusher9mil]

@GarageTinkering and this is what happens when someone assumes another person's car has a feature, duh 🤦🏻‍♂️ 😁😂🤣

[@mikecrane2782]

Great stuff, be using these displays for my upgrades too. 👍

[@GarageTinkering]

Ooo, what car?

[@mikecrane2782]

Panhard PL17 - I’m putting a more modern engine in it so can’t use mechanical drive, and was adding a 3D printed 52mm gauge which I’m going to swap out for one of electronic equivalent ones.

[@GarageTinkering]

Wow that's a unique looking car. Honestly never heard of those before. So cool.

[@DrFiero]

Tie the wire from your OE backlighting into an input pin on the controller (with a pull down of course!) and monitor it so it dims when you turn on the lights? Maybe you're already doing that and I missed it in a previous video.

[@GarageTinkering]

That's one way, but I'm already sniffing CAN data and it's a simple bit flag in there so much easier to grab that way

[@DrFiero]

@@GarageTinkering - Yes! Totally. Senior moment. I keep regressing to analog (Pre-OBDII) due to the age of 1/2 my car fleet!

[@GarageTinkering]

@DrFiero ironically enough next week's video is about converting analogue signals using ADC, which would cover most of those kinds of sensors and senders

[@DrFiero]

@@GarageTinkering - there I am, back in your brain again. 😈

[@mikecrane2782]

Cheers, well odd design but handle well, pretty aerodynamic, a good 90mph on 850cc air-cooled flat twin. Heavy steering but perfectly practical for what they are.

[@contentnation]

I like the project so far, but one thing would bother me, if I would do it. I'd prefer an RS485 bus over using espnow. Since you only use one-way communications, you'll get away with simple TX -> parallel RX as well, but RS485 would allow simple expansion. Also this enable to mix in cheaper controllers without network or more powerful for more fancy stuff like a teensy. RS485 is a dirt cheap 8 pin chip plus a few resistors.

[@Dave080109]

Wow I’ve only just started watching your videos and may I say what you are doing is amazing, I have a suggestion as to the dimming of the displays when the lights are on and that is can you tie it into the clock function, the reason I say that is most cars that have auto lights, the displays turn on night mode the moment the lights are turned on, so for example if at 10am your car turns on your headlights, your dash turns on night mode, but if you link that function up with the time and the GPS,then it would know that a 10am here in the UK it would not need to put the dash display in night mode, I really hope this makes sense

[@GarageTinkering]

I'm actually going to go one step further than this and integrate external light sensors to add an auto lights mode and by proxy an auto screen dimming function; so you're right with that idea, I'm just taking it a step further. There's also a short term fix to do it to sundown / sunset, which I can get from the weather API

[@Hediis]

I'm so glad that I came across your channel! I've thought about how to solve my speedo problem now that I'm removing the mechanical wire and rebuilding my car. I noticed that you will be adding 4" displays, have you found any good candidates? Thank you for sharing your project!

[@GarageTinkering]

Painfully I need a 4" and two 3.5". I found some on AliExpress that look like they could do the job but I've not looked into them enough to pull the trigger yet. Ideally I'd like to find some that are fully integrated this time so that I can avoid the various tearing issues that I'm getting with these current boards.

[@PetesWorkshop]

Isn’t 2.1” a bit small to replace the originals? If going to a larger display how hard would it be to re-scale the SW to suit?

[@GarageTinkering]

The originals are smaller than 2.1 inch. These are the top of center console gauges, not the console ones. Those are around 4 inches, and will be getting done next. And rescaling is all pretty simple but a bit arduous as you'd have to resize all the fonts. Otherwise it's just a matter of adjusting the component sizes and the placement

[@Uncle-Quinns-Garage]

DOPE! I'm just gonna say in advance that I love you because in about 6 months I'll be saying it again and not remember your name. We should chat, I'm gonna make a batmobile-esque Datsun 280zx race car with a Jarvis like system that adjusts/controls aerodynamic elements and edf fans as a kind of hybrid fancar/wicked batmobile.

[@Uncle-Quinns-Garage]

Also, you'll need your tach more in a racing environment, on the edge you won't care about your speed, but you will care if you blow up your engine.

[@GarageTinkering]

Oh man, I desperately want a 240! I think I'm going to pull the trigger on a Z32 300zx this year to tide me over though

[@mygt8351]

Pretty cool set-up. Would love to learn to build a custom gauge cluster for my turbo legacy that has multiple functions like these. My PLX gauges keep dying on me, but i like the ability to switch between gauges though.

[@mygt8351]

How difficult is the programming?

[@GarageTinkering]

Depends how much programming experience you have

[@mygt8351]

Not much but willing to learn.

[@danni4697]

Another great video! Could you share on how you reverted the gauge on for example the oil temp scale? I tried switching up the min/max value and a couple of other things though it didn't work as expected.

[@GarageTinkering]

Exactly that. Start value and the max number, low value as the min, and then the outline range goes from max to min too. Then the value you can just set as normal. All this code will have been refactored and out tomorrow if you'd like a look at it

[@danni4697]

@@GarageTinkering Sounds good, thank you! I'll look into the outline range, might have forgotten that lol

[@GarageTinkering]

@@danni4697 If your outline arc is going "the long way around" the left of the screen, that's what it is

[@phil210293]

Great series, I've been mulling an idea like this over since before round screens were really a thing but I lack some of the technical competency to make it happen, now I can accomplish it thanks to your heavy lifting! With regards to your framerate, have you tested with all the serial print statements removed, since you won't need them once they're in the car? They can absolutely eat time, especially on arduinos, I don't know whether the same applies for ESP32 but something to try?

[@GarageTinkering]

Yeah they're not really a big issue. It's definitely the full screen redraws that are doing it

[@DaSlimss]

Would be nice to see one screen that can switch between different gauges,in example turbo boost,battery voltage,coolant temperature,gas level,etc. Because my dashboard does not show coolant temp and I want to install digital screen/gauge in original gas gauge place. To understand better what I mean look at Opel Astra H/ Vauxhall Astra MK5 dashboard

[@GarageTinkering]

My best mate has asked for one of these on his EP3 track car, so... it's coming :D

[@DaSlimss]

Sweet!

[@RockNLol2009]

I did not yet watch all your videos, but follow along for a few already. Do you have all those ESP32s in the same WiFi and share data wirelessly?

[@GarageTinkering]

They use ESPNow, which is a stateless, none-persistent wifi signal. Super useful. This video has a more in-depth look at it kzbin.info/www/bejne/nqaueqmnqc91nZY

[@frednerk5959]

Do you need an ESP32 for every display or is there a way of "daisy chaining them"?

[@GarageTinkering]

There are some boards that drive multiple screens, but honestly I'd recommend this approach and having one per screen. You massively reduce the frequency of running into CPU and memory limits by trying to handle too much stuff in one board, plus you create a better separation of concerns by allowing each board to just control and handle one small set of processes.

[@frednerk5959]

Thanks, I was just thinking of installation issues when you haven't a lot of real estate to play with. 👍

[@GarageTinkering]

​@@frednerk5959it won't be a problem for this build as I have tonnes of space, but might be something to look at for others for sure. They might be better off with more integrated screens with onboard controllers as they're typically much smaller

[@Robert-im5df]

Great work ! Could you please share the most recent source code ?

[@GarageTinkering]

As I mention in the video I'll share it later in the week when it's gone through a clean up and slight refactor for performance. Friday probably. Link will be in the comments when it's up

[@fredthebulldog529]

Can you share your lvgl configuration file? Your transitions are pretty smooth and I'm using an esp32s3 my transitions are a little choppy still. I've gone through and adjusted the screen buffer, the memory allocation, made sure its all running within SRAM and not PSRAM, enabled double buffer with DMA, etc.... it works ok but yours look just a bit smoother. Perhaps it's slower transition speeds helping but if you could share your lvgl conf That would be awesome!

[@GarageTinkering]

Sure. I'll be uploading the polished and refactored code for this tomorrow, so I'll put the conf file up there too. Otherwise if you're on Discord send me a DM and I'll wing it over.