Connect a UNO to a 4" LCD (420X380 ) with ILI9486 driver in SPI mode

hello,
first ,I apologie for my language :I am french and quite new in the "Arduino world"...
I try to connect a UNO to a 4" LCD (420X380 ) with ILI9486 driver in SPI mode . I use LCDWIKI library ….
After loading example found with the library ( ie : display txt ) my LCD blink once but no txt appears ...
I have cheeked many times , tried different wirring ,different library ( GFX , ...) without succes .Only the backlight is working!!
….
may be the init is no good ..I do not undestand the difference between software SPI and Hardware SPI ...
thank you if somebody help me .
bruno
note : i am not alowed ( I have modified my accompt and I am considered as "new" ) to send a file of my code ...

Please post a link to the actual display that you have bought. e.g. Ebay sale page.

The Forum Software is VERY inconvenient.
What are the specific rules for new members ?
I can understand that the Forum wants avoid SPAM.

David.

@bruno13660_1

TOPIC SPLIT
PLEASE DO NOT HIJACK!

Could you take a few moments to Learn How To Use The Forum.

Other general help and troubleshooting advice can be found here.
It will help you get the best out of the forum in the future.

You also appear to have created 2 accounts, although the other one has not been activated. Please can you delete the other account?

@Perry,

Are the "New Member Restrictions" published anywhere?
e.g. attaching files
e.g. posting messages
e.g. posting images

There is excellent advice on "How to get the best from a question"
But I can't find any "New Member" rules anywhere.
Or whether they are lifted after a day, a week, ...
Or whether they are applied to joining date or first post date.

It's described here.

I think the admins can tweak the settings though. Basically, you can quickly remove the original restrictions by reading a few threads.

1 Like

Thanks for the link. Is it actually published anywhere?
I presume that a new member might be informed.
As an existing member I have never seen this before.

Anyway, in summary:
A Trust Level 0 user is restricted to <= 3 topics, 1 image, 0 attachments, <= 2 links, <= 10 replies.

If this poor deprived user were to Spend a total of 10 minutes reading posts she gains Trust Level 1 e.g. images, attachments.

When a new member whinges about restrictions we can just tell her to read for 10 minutes !!

There are other ways to gain Trust Level 1 but reading posts seems the most practical method.

Incidentally, I always request a link to the actual display in question. And quote library example by name. Which is well within Trust Level 0.

David.

1 Like

From the instructions that @wildbill linked to:

Every new user gets a welcome PM mentioning the trust system and linking to this blog post, explaining that new users may be temporarily limited for safety reasons.

I have a similar problem as a mod I don't always know what the forum looks like to a regular user.

hello ,

I have bought the display to ALi express :

and for the level shifter ( for each signal between the display and the Uno ):

Convertisseur de niveau logique bidirectionnel 8 canaux, 5 pièces, haute vitesse, Duplex complet 3.3V 5V pour Arduino Raspberry Pi | AliExpress.....

I did answer you for the "new member restrition " in an other reply .

Thank very much for your help .

hello I apology to create a second account . to day my old account was out of order ( it ask me to activate but no way to do it ) I am about 3 years old member ??? any way ,I will discard my old account .
escuse me for the trouble ..;
bruno

Do you have 2 other accounts? Maybe the account I found is not you. The account I found was about 1 day old (I think), certainly not 3 years old. Can you send me a PM with a link to your old account and I'll see what I can do.

hello
after all these " administrative" problem , nobody answers me about the difference between "software SPI and Hardware SPI ...
I look for some information ( software exemple ) to set correctly my LCD . 4" , SPI ,driver ILI9486 with UNO
thank's
bruno

Hardware SPI means there is specific, dedicated hardware in the micro-controller that does the SPI function. The micro-controller just tells the hardware what to do and leaves it to get on with the job, freeing the micro-controller for other things. Software SPI means there is no dedicated SPI hardware (or there is but it's not used) so the whole SPI thing has to be done in software, which demands a lot of processor time and is much slower than using hardware SPI.

I don't know the answer to the rest of your question, sorry.

Which particular LCDWIKI library? provide a link.
Which example? quote by name.
Have you edited the constructor statement?
Copy-paste the changed constructor.

I Googled for LCDWIKI ILI9486 and got http://www.lcdwiki.com/4.0inch_SPI_Module_ILI9486

Then downloaded the "4.0inch_SPI_Module_ILI9486_MSP4022&MSP4023_V1.0.zip"

and ran this example
Demo_Arduino\Demo_UNO_Hardware_SPI\Example_01_Simple_test

which specified this wiring:

//             CS  DC/RS  RESET  SDI/MOSI  SCK   LED    VCC     GND    
//Arduino Uno  A5   A3     A4       11      13   A0   5V/3.3V   GND

Obviously you should use level-shifters on each of those signals.
This simple example uses no special libraries.

You can then try the LCDWIKI libraries e.g. display_graphics.ino with the same wiring.

Everything should work. If you have a problem, you can quote the example name. Then I can replicate your problem.

Please note that your chosen display requires a lot more effort than simply plugging in a ready-made Uno Shield, installing an approved library from the IDE Library Manager and running the library examples.

David.

@ david
ho thank very much to help me !!
I have found and loaded the library LCDWIKI by the same way than you suggest but I wanted verify your links and ... I have found a small difference in the LCDWIKI_SPI.h :on "your" file there is one line more : ILI9486_18 and it is a great difference !!!
I have load that file and


some exemple and ... my display is working fine !!
on my old program I wrote :
#define MODEL ILI9486
LCDWIKI_SPI mylcd(MODEL,CS,CD,MISO,MOSI,RST,SCK,LED);
and now i write : define MODEL ILI9486_18
and the driver is well selected !!!
Thank you so much for the good information and to give me the courage to restart test with another solution !! this is a great value of internet !!!
I try to send a picture ..;
best regards
bruno

Well done !

LCDWIKI works but is fairly crap.

All the library methods are badly spelled and don't correspond to normal human intuition.
Which makes it difficult to port an existing sketch to their strange badly spelled syntax.

David.

OK I heard your argument ... Now ,I know that my LCD is working an the wiring is good . If I find a better library ,i will change ...
note :I have not selected display on shield because it must be very thin ( my project is to replace an old LCD display which became black ( mushroom between the 2 slide of glass in a marine GPS )

do you know a good library ( with the good driver ! )for that display ( 420 x380, 4",SPI ,ILI9486 )
bruno

@PerryBebbington
thank for your clear answer . I thought some thing like that but I did not understand why they use the same pin out for hardware or software SPI .
I have seen hardware SPI is faster than software .
Now the display is well working !! the font are not very nice for large letters with that library . I am looking for an other library to get better results ... but I am glad to improve !!!
thank a lot
best regards
bruno

1 Like

If hardware SPI exists, and it is pretty standard on most if not all micro-controllers, then it does not make sense to use software SPI, and even less sense to use it on the pins that have hardware SPI available on them.

Something you will come to realise is that the library code for hardware SPI (and I2C) does not make full use of the available speed increase using the hardware can give. Often there is a single function call to send or receive data, so the code goes away and does that, and does not return until it's finished. Ideally there would be a background task to service the hardware until it has finished, allowing the rest of the micro-controller to go off and do something else. Hardware is still a lot faster than software, but not always as fast as it could be.

@bruno13660_1, @david_prentice, bonjour Bruno, hello David,

Thank you for this topic and the information provided!

It helped me get a 3.5" ILI9486 SPI display working finally.
I got it about 2 years ago and failed to get it working. So I had put it aside.
SURENOO 3.5 inch 320*480(RGB) 8PIN SPI TFT Color LCD Module Display Screen with PCB Adapter Board ILI9486 Driver.
I don't recommend it, as it has no CS line.

The hint to try the Demo_Arduino\Demo_UNO_Hardware_SPI\Example_01_Simple_test proved that the display was working.

The hint define MODEL ILI9486_18 told me why it had not worked for me, it needs 18-bit mode for native SPI, like the ILI9488.

I have updated my libraries ILI9486_SPI and GFX_TFT with support for ILI9486 with native SPI.

I tested with ESP8266 Wemos D1 mini and Seeduino UNO switched to 3.3V.

Jean-Marc

I have never seen this display before.

If they wanted to use less pins they could have used a single SDA and replaced MISO with /CS
You can enable bidirectional in software e.g. to read GRAM or registers.

Life is VERY difficult without a /CS pin.

David.