TFT LCD screen info?

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chipset

Senior Member
Hey guys. This is more of a question based on where I should start looking more than anything else and beyond that I know anything on this scale is well beyond my skills at this point but I love learning especially about things that interest me.

Ok well nowdays more and more auto manufacturers are integrating TFT lcd screens into their cars and some are even starting to create virtual instrument clusters as well (instead of using analog needle and scale style gauges). I then came across a company call magden technologies which makes a box that integrates vehicles sensors and onboard diagnostic data to drive an in car lcd screen with a virtual dash. Other companies have started producing other "screen" based instrumentation in different types of configurations.

It kinda peaked my interest if a pix axe could be used as the brain behind some kind of unit like this. I searched around and the best Ive found is more or less info for LCD displays like a 16x2 ect. Due to the lack of info (or my lack of using the correct verbiage) I wanted to ask if anyone had some info or points of interest on the web regarding a microcontroller based lcd screen display. I know this can be done with a CarPC but micro's are so much better suited to a car.

What Im looking for is any info about making a graphic display and integrating it with a micro. Im hoping maybe theres a product or line of products that have the hardware to run the screen and a program to create the graphics and all they need is input from a micro in order to display the changing info from different sensors.

Like I said I just want to start learning about this type of stuff not someone to attempt to design it for me. Im just curios if this stuff is feasible for a one off project designed by a poor handicapped individual like myself lol.

Hope you guys have some links I can look at to start figuring out what all is involved in making something like this.
 
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BCJKiwi

Senior Member
Surely the first Q is 'how to access the data?'

Depending on the info required and the age of the car, the simplest way is via an off the shelf OBDII module. Otherwise you would need to install your own CAN devices.

Off the shelf OBDII modules are normally 'Read Only' - i.e. send a request for info and receive the data back as opposed to writing to the Car computers.

These modules are eminently picaxeable via the typical serial interface.
 
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chipset

Senior Member
ahh we're getting off to the wrong start. No I dont want to know how to access obd2 data or anything else, that wasnt the goal. At this point I was trying to see if anyone could point me into the right directions about having a tft lcd graphically display data fed to it by a micro.

here was my plan that I was hoping to follow to see if I could find the hardware for something like this...

micro (picaxe) reads digital or adc pins>> sends data to yet unknow processor that can display said data on a tft screen.

I was hoping that maybe there was a hardware/software solution that allowed you to make a graphic interface that fed a screen and took its raw data froma picaxe or similar microcontroller.

I was just giving examples of what I was looking in to possibly doing (if I could muster up the capabilties). I dont want to access OBD2 data though, I wanted to feed the pic a bunch of 0-5v signals from sensors and send data to another module that could then interpret that data and display it as a user defined graphic.

I was hoping there was a graphics solution that could do that and thats pretty much what Im asking about.
 
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BeanieBots

Moderator
Well, with all the normal caveats about putting electronics in a car.
(Don't, unless you know exactly what you are doing).

The obvious (on this forum) has to be this:-
http://194.201.138.187/epages/Store.storefront/?ObjectPath=/Shops/Store.TechSupplies/Products/LED042
It even has a built in graph routine.
It has also has a 'pointer' which can be used as a "needle".

Not the fastest display in the world, but worth a look at and VERY easy to drive.
Have a look here for some screen shots and example code.
http://www.picaxeforum.co.uk/showthread.php?t=12505

You can also get LCD DPMs.
They resemble an analogue meter but have custom LCD displays instead of a meter. RS & Farnell have them in the DPM section.

One thing to bear in mind with graphic displays is how data you need to send.
Just think about how big a 'picture' is and then ask yourself where that information is going to come from and how it will be coded.
 
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BeanieBots

Moderator
Yep, something like that is readily available.
It's called a LapTop:rolleyes:

Simply hook up your PICAXE to the serial port.
Write a graphics routine and read in the data from the PICAXE.
 
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chipset

Senior Member
did you read my post?? I was asking if there was ANOTHER module that could take data inputs from the picaxe and through that other module do what I posted.... Im well aware a picaxe is no where near in the right universe of doing what I posted but on a basic input output plane the pic can definitely do that.

I was asking if the clever minds that be in this forum know of a hardware/software solution that could do that.

I also already admitted that a CarPC aka "laptop" could do that but I was looking for microcontroller type hardware that could do the same thing. Im just not that educated on mobile graphics controllers be it cell phone displays or higher resolution ones. I just want to learn about it and I was hoping peopele in here would have links to that kind of thing so I could read about it. I was really hoping I wouldnt get sarcastic responses especially from a Mod.
 
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BeanieBots

Moderator
Sorry if you took that the wrong way but what you are asking for IS a laptop.
You need a processor with enough power and memory to drive a graphics card which in turn can drive the display.
That is a laptop minus the keyboard.

You will need to write your own graphics and how your data will manipulate the graphics the way you want.
To program it you will need a keyboard. Back to a laptop again.

Is there something already available, pre-programmed and able to use YOUR data? Except the one shown in the video which is a complete unit already done and specific for the intended purpose, I doubt very much that you will be able to find an OEM version.
Even if you did, I bet it would be more expensive than a laptop.
 
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chipset

Senior Member
sorry if I took that as a sarcastic comment but it sorted seemed like it. All Im getting at is that cars of all makes have different types of displays all shown through a tft lcd display. The Prius has the fun little graphic that shows how much power youre using. Others have Sat nav. BMW and Merc have the Idrive and variants which are menu driven displays.

I know that a flash based controller is out there because they are alreaedy in use. Im hoping that somebody or maybe many people have knowledge of these and could give me links to them. More or less I just want to learn how this technology works and to see if its possible to make something of the same sort but with a design of my own.

Even if it cost $800 it would be worth it if you compare how much aftermarket gauges for a car cost (average cost is a $1000 us)
 
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Dippy

Moderator
Chippy, if you want something as fast and flashy as that video it is well beyond your average PIC.

I suspect it would beyond a 4G too as you would be limited by memory and serial transfer.

This is in the realms of a something really healthy with gallons of mem.

Unless you can get hold of one of those generous C men to programme something fancy then I would suggest you start off a bit more modestly.

Or get one of those Windows CE based thingies and write something in that.

I reckon even the fastest PIC writing to a QVGA GLCD would be pretty slow for shifting all that graphics.
 
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chipset

Senior Member
believe me at this point I can barely touch my toes with the basic commands of the pic axe let alone do anything like what I showed, Like I asked from the start I was hoping some of you guys may be up on stuff of this sort and be able to link me to hardware datasheets that may be used for this type of thing.

All I want to do is read about it and see how and what the OEMS and other companies may be using to do this type of thing. All this question is about is to learn.. thats it. If it takes a software developer to design this type of thing then so be it. I just wanted to se if the hardware was available to a little guy to make something like what Magden (the company I linked to )built. If not then fine, but at least Id learn a little bit more about the subject.

Like this story http://www10.mcadcafe.com/nbc/articles/view_article.php?section=CorpNews&articleid=314278

TI makes micros to do this. I was wondering if there was a mor complete solution for this type of thing (even if its expensive) Im just seeing if there are systems out there that can do this and maybe even be able to do it with picaxe integration
 
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Dippy

Moderator
Sorry, can't help.
Hopefully someone can search and find some information for you.
It does look very nice doesn't it.

If you wanted something less flashy/animated/fast then there are some serial to VGA devices around. Not cheap though. And the ones I have seen wouldn't have the memory to give you fancy resolution like that thing.

On a serious point though (and not being at all sarccy), even if someone provides you with a link to show the guts of something like that thing, where will it get you? They may have custom components and certainly a fancy micro containing thousands of lines of code. I just worry it may confuse more than educate?
 
hippy

hippy

Ex-Staff (retired)
Most cheap and large LCD screens ( laptop, PSP, DVD player ) don't have any screen memory or clever controller but require the screen to be continually refreshed. They often have three 8-bit signals for RGB so that's a miminum of 24 I/O lines required and the individual pixel data needs to be clocked out at multi-MHz speed ( 6MHz+ for 640x480 @ 50Hz ). You also need 1MB of fast memory to hold a 640x480 24-bit RGB image.

VGA capable screens improve things I/O-wise but still require continuous refresh at high-speed and needs memory, but it would be possible to interface a graphics card to a micro.

There are micros and interface chips which can control large LCD or VGA ( or none of the products would exist ! ). A Google search is a good place to start. You can find a micro with enough memory and a VGA interface that will handle 640x480 in 4 color for under $20.

A PICAXE could connect to such a system but then the issue of speed comes in to it, though that depends on what you require; it takes time to update the screen and longer the more you have to send.
 
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MartinM57

Moderator
I'm sure what chipset is after is a nice TFT lcd display with a nice and simple interface like the GLCD LED042 offering from
http://194.201.138.187/epages/Store.storefront/?ObjectPath=/Shops/Store.TechSupplies/Products/LED042
- but a bit bigger and a bit more powerful.

So putting one side all the:
- don't do anything regarding homebuilt electronics in cars
- you'll not get what you want without the power of a laptop
stuff, anyone with any leads on suitable hardware?

@chipset - I sympathise with you ... I've looked for things like this in the past but haven't found anything :(

@BCJKiwi - do you have any references to OBD/CAN readers that are microcontroller friendly (read-only and perhaps read and wrtite)?
 
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MartinM57

Moderator
@kr - I wish you hadn't posted that ;)

I can see a price for the Quick Start development kit, but not the per-display price...
 
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moxhamj

New Member
Kevrus, those displays are fantastic. The serial commands (and other protocols) would make things a lot easier to use.

I guess ease of interface might lead to suggestions here http://www.4dsystems.com.au/products.php

But I'm not sure a picaxe can drive those. Just think of how many pixels you need to turn on and off and the memory of a picaxe. So you would need big memory as well, eg the uDrive.

The propeller can do vga and TV (eg via the TV in on a portable DVD player). But you need to learn a new language.

Or there is the laptop suggestion. I'd look at that first, even if to just experiment with working with graphics. Turning pixels on and off, moving pixels. Write it in vb.net on a laptop, then look at porting the working code to something else.
 
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kevrus

New Member
Martin, if you look at the section marked 'graphic dip' and scroll down, the prices for the intelligent displays are there..not sure if they are the latest prices though (which I do have but not on my home pc at present...)

Dr, they are very appealing. I was pleased as punch when I first used a 2x16 alphanumeric...didn't take long before I needed (read as wanted) a 4x20. Have now moved up to a 128x64 graphic, and before boxing up my first project with that, I now want to re-do it with a 240x128 graphic...I guess colour is next as per 4dsystems...where will it all end, 60"plasma?
 
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Andrew Cowan

Senior Member
That's weird. In the price column, I have to right click on the little blue symbol, select properties, and then look at the 'alternative text' part to see the price.

A
 
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BCJKiwi

Senior Member
@ Chippy,

In my (admittedly limited) experience in this area, there is not much that you can 'ADC' or read digitally in any meaningful way on a modern car - that's the point I was trying to make. Have looked at trying to read rpm, speed and a few other simple things of that nature from current cars and gave up on it - there is little info available on the wiring, and every module - such as a single cluster of the instruments - has it's own CAN node.

If you want to build new independent pickups for each bit of info you want then that may be a different story.

Would be interested in what info you wish to process and how it might be gathered - always interested to learn!
 
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kevrus

New Member
Apologies, I should have mentioned that you need to hover the mouse over the little blue icon, Andrew found it...( passed the initiative test :) )
 
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chipset

Senior Member
BCJKiwi said:
@ Chippy,

In my (admittedly limited) experience in this area, there is not much that you can 'ADC' or read digitally in any meaningful way on a modern car - that's the point I was trying to make. Have looked at trying to read rpm, speed and a few other simple things of that nature from current cars and gave up on it - there is little info available on the wiring, and every module - such as a single cluster of the instruments - has it's own CAN node.

If you want to build new independent pickups for each bit of info you want then that may be a different story.

Would be interested in what info you wish to process and how it might be gathered - always interested to learn!
Click to expand...
you then would be very mistaken lol. Not only is there a ton of info available, I have it available to me as well. Beyond that I could name off well over 20 different things you could ADC or digitally monitor and there are cheap, reliable sensors available off the shelf with the wonderfoul addition of having the specs avaiable on the signal performance at different parts of its range. Fluid temps, fluid pressures, air temps and pressures, fuel level or any other level in a tank, engine speed, vehicle speed, gear position, wheel speed, voltage, current draw, displays for what lights are on in the car such as turn signal indicators, high beam indicator, generator light. Hell the list could go on for quite a while. Along with that if you do some math between different sensors you can calculate things like hp (which based on mass airflow into the engine over a certain amount of time) or performance data such as lateral acceleration or straight light acceleration. Needless to say there are more than a few things to monitor on a vehicle.

You also seem to forget that there are over a 100 years worth of cars on earth and over 90% of them dont have any CAN network, serial bus or even digital fuel injection. Hell some cars a bit more than 50 years old dont even have electric turn signals and moreover hydraulic brakes. Classis cars and their owners love to upgrade their car and have cool stuff in them. An LCD screen based gauge cluster would be a huge seller for the creator of it as long as was built to be adaptable to different vehicles. What Im trying to get at is that there are a lot of people that spend money on cars that may be older than you and this kind of thing would be definitely popular in this time and age.

Ive seen alot of guys here bring up LCDs them selves, what I was trying to find out if there was a module, chip or development board that you could plug into any off the shelf lcd screen like the onece that are in some cars head rests or the like. They use RCA cables to recieve information from a modul elsewhere in the car, just like a dvd player and your tv. I wanted to see if there was something that acted as a go between a microprocessor and an lcd screen.

Hope Im a little clearer about this and Im not at all concerned about the obstacle involved in actually monitoring anything. Forget its even going into a car.

Lets say you wanted a 7" LCD screen or even a lcd computer monitor to graphically show you how hot it is in your home. You have a thermometer hooked up to a pic to read the varying 0-5v signal from the thermometer. The pic then send this info to the magic box Im asking about. This magic box is not a personal computer. The magic box has a software program that would allow you to make a grapghic interface for whatever it happens to recieve from the pic. ONce it does this it then send out a signal to the monitor via a video driver of some sort.

NOW, does a magic box of this sort exist in any way, shape or form for consumers to buy? Ive learned alot of companies find a premade technology and adapt it to their needs. Im wondering if you guys happen to know of anything like this that is available?

Oh and then there are graphic cauges like these http://www.plxdevices.com/multigauges.html . They use an OLED housed in a circular gauge housing with a small cigarette box sized module that handles the signal inputs and also driving the OLED. The have a program that allows you to design your own gauges by drawing different pictures for each step of the gauges movement. This allows for animation of the entire gauge and the end result is something that is totally end-user customizable as well as versatile. Take into account that a standard set of analog gauges of high quality will set you back AT LEAST $800 us. This route doesnt allow for customizing and if you want to monitor something else you have to buy a new gauge. This is not only expensive but some gauges just arent available. When was the last time anyone made a horsepower gauge? How many people made that gauge with a picture of the car in the backround? This is only possible with an lcd style application. Im hoping to learn about this technology and how I may be able to do it for myself.
 
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chipset

Senior Member
I just came across a part of google I didnt know existed and found something that some guy succesfully did using an arduino. Im going to read up on it but Im sure a picaxe could be used to do the same thing. look up ROBOTMETER on google code and you can learn about what this guy is doing. Looks pretty promising . More or less it gives you a gist for what I was wanting to find info about.
 
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BCJKiwi

Senior Member
So how do you pick up RPM on a modern car that is entirely CAN with a node in the instrument cluster, coil on plug etc etc.

Looked at strap on magnets etc on the drive shaft for wheel speed and trying to work with the ignition system as well as the instrument panel for RPM.

Am unable to locate wiring diagrams and am reluctant to strip apart insturmnent clusters and poke about to find something that might be useful.

I certainly don't have access to wiring diagrams of the detail required for either of the last two cars I've owned and the dealer/workshops are most unhelpful - one european and one Japanese.

Maybe things are different in the US?
 
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chipset

Senior Member
actually getting an RPM signal from a coil on plug vehicle is pretty easy. With off the shelf parts you can get a tach adapter and reference it off of one coils trigger leg. Thats the normal way to add an aftermarket tach to a coil on plug car. And no its definitely not different in the US. Heres a link to MSD for the product Im referring to http://www.egauges.com/pdf/AutoMeter/561.pdf . Even with a ton of crazy electronics, there are ways to deal with them. Its even possible to run a tach directly off the crank sensor itself but thats a whole other thread.
 
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lbenson

lbenson

Senior Member
Re the "laptop without a keyboard" ("headless" device), the specs on what you pointed to seem dated to me: 200MHz ARM9 CPU, 32MB SDRAM (64-128MB opt), 32MB NAND Flash

The best in this line that I have seen so far is the Sheevaplug. Same price ($99), 1Ghz, 512MB Ram, 512MB Flash, SD. Everything must be connected through ethernet or 1 usb port or serial port (usb hub works, tho) (gpio pins available, I think). Active forum here: http://openplug.org/plugforum I think I have seen 12V mods.

Product description and purchase link here: http://www.marvell.com/products/embedded_processors/developer/kirkwood/sheevaplug.jsp

Identical price and form factor announced here for 1.2Ghz version: http://www.linuxdevices.com/news/NS3883004256.html
 
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BCJKiwi

Senior Member
@Chipset,

Thanks for that,

Had already written off those approaches as being way too expensive and too complicated specially when moving from vehicle to vehicle.

Found it much simpler, tidier, faster, and non warranty compromising, to use OBDII which can deliver all the information I was looking for through one standard connection.
 
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chipset

Senior Member
lbenson said:
Re the "laptop without a keyboard" ("headless" device), the specs on what you pointed to seem dated to me: 200MHz ARM9 CPU, 32MB SDRAM (64-128MB opt), 32MB NAND Flash

The best in this line that I have seen so far is the Sheevaplug. Same price ($99), 1Ghz, 512MB Ram, 512MB Flash, SD. Everything must be connected through ethernet or 1 usb port or serial port (usb hub works, tho) (gpio pins available, I think). Active forum here: http://openplug.org/plugforum I think I have seen 12V mods.

Product description and purchase link here: http://www.marvell.com/products/embedded_processors/developer/kirkwood/sheevaplug.jsp

Identical price and form factor announced here for 1.2Ghz version: http://www.linuxdevices.com/news/NS3883004256.html
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wow that really is cool and for the price I think it would do anything I could dream of. It runs on 5v DC so as long as the power stage is adequate this will run in a vehicle just fine.

Beyond that I guess I would need to learn how to develop an application for it. Anyone wanna help? Id pay for the hardware and Im good at graphics as well as being very well versed in the external hardware for a vehicle enviroment for getting data to the thing. I suppose what would be necessary is to draw pictures for the gauges as an animation that could be done in Adobe Flash and then have an application that could take the inputs from the sensors and create the graphics for output.

I know its easier said than done but this type of thing isnt that crazy as Im not planning on making it integrate with obd2 (although there are programs that can read it so it may be a possibilty).
 
C

chipset

Senior Member
BeanieBots said:
Yep, something like that is readily available.
It's called a LapTop:rolleyes:

Simply hook up your PICAXE to the serial port.
Write a graphics routine and read in the data from the PICAXE.
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Well after a lot of searching and asking people that own the particular product I linked to about magden-auto, I figured out that all it is an overpriced CarPC :rolleyes: They are selling it for $950 us as a base unit and the same thing could be put together with more processing power and many more features for way less than that. All this time I thought that it was a microcontroller and it definitely isnt. As soom as I was shown the boot up from a key off position it told me that it was a CarPC. They just customized the boot screens and such to cover up this fact. Either way I now know that what I thought was an elaborate piece of electronics is just an overpriced computer with a basic program running on it. Even I was impressed until I put two and two together.

I now know why most Micro controlled instruments of this type are rather simple in their displays, anything other than the most basic shapes require more processing power than a micro can handle.

I may still go this route cause its something that I have obsessed about for a long time but at least I know it takes a PC to do it.

Thanks guys, the links regarding some of the screens are worth it for having this thread up.
 
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GreenLeader

Senior Member
BCJKiwi said:
So how do you pick up RPM on a modern car that is entirely CAN with a node in the instrument cluster, coil on plug etc etc.

Looked at strap on magnets etc on the drive shaft for wheel speed and trying to work with the ignition system as well as the instrument panel for RPM.
Click to expand...
I made a logger for my car, which has carburettors and no modern electronics. I measured my signals using fairly cheap sensors:
- rpm with an inductive pick-up on alternator fan, and a simple circuit with an LM2917: would have used toothed cam pulley, but its made of aluminium :(
- road speed with an inductive pick-up on the toothed wheel for the ABSwheel speed sensor (my car has the toothed wheel, but not the ABS!
- turbo boost with a cheap pressure sensor plumbed in to existing sense lines
- intake and ambient air temperature with LM35's

I am also quite keen on a graphics display that I can drive with a Picaxe to show some of these signals in the car....
 
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Cosmic Software

Member
I hope that I am not missing the point (I did skip through the last couple of pages), but from what I understand, you are asking us to forget the application, and just find a solution to driving a TFT monitor.
If you have a monitor with a 15 pin VGA connector, then there is an IC that I think might be quite useful.

Have a look at http://www.tvterminal.de/doli.html

It is not capable of generating computer quality graphics, but I think that that would be asking too much. At 28.70 Euro, it is fairly priced, and may interest quite a few people.
 
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chipset

Senior Member
well like any thread people can add to it as they like. As far as Im concerned, I more or less found out that the system I was trying to emulate was in fact an overpriced Carputer aka CarPC. They just customized the boot screens to show their logo and a disclaimer about watching tv when driving blah blah blah..

Regardless, since this has come to light and the fact that CarPc's can be built for a few hundred dollars on the low end, I decided that a micro controlled setup would be way more work than its worth, especially when the CarPC already has programs written for it.

There are a ton of other things that the Pics are good for though, graphics arent one of them though..
 
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