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Forum Index : Microcontroller and PC projects : ILI9481 IPS 480x320 display not recommended

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matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10627
Posted: 07:06am 09 Jul 2022
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I've now received my display which I bought to support including a driver for BigMik but can't recommend this display for the following reasons

It's slow. Most display controllers are happy with 24MHz SPI. Mick's only works at 16MHz and mine only works at 12MHz. Others on the web have reported this as well.

RGB565 doesn't work which means the driver has to use RGB666 which uses three bytes per pixel rather than two - this increases access times by a further 50%

Can't use BLIT. Although the controller chip is supposed to allow reading the framebuffer there is no evidence of activity on the MISO pin from the display. As it happens the ILI481 driver will also initialise an ILI9341 so I can test that the framebuffer read primitives are correct and work but there is no activity on the ILI9481.

I suspect these displays have been built from a faulty batch of controller chips hence the comparatively low price.

Mick, I have fixed the portrait  etc. orientations and will include in the next beta
Edited 2022-07-09 17:07 by matherp
 
bigmik

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Joined: 20/06/2011
Location: Australia
Posts: 2971
Posted: 08:32am 09 Jul 2022
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Hi Peter,

That is disappointing about the speed, or lack thereof, Thank you for looking at it for me though, you did a wonderful job of getting it going, especially as you didn’t have a display at the time.

Thank you for fixing the driver orientations as well. I will just use them in places where I need the extra viewing angle and the speed is not a major issue.

Will the driver be set at 12MHz or can it run at 16 via an option? Either will be ok by me.

Take care,

Regards,

Mick
Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<
 
panky

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Joined: 02/10/2012
Location: Australia
Posts: 1116
Posted: 10:01am 11 Jul 2022
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Peter,
Does this caveat also apply to the 26 pin RPi 3.5" and 4" displays based on the ILI9481 (blue pcb and no SD card),
Cheers, Doug.
... almost all of the Maximites, the MicromMites, the MM Extremes, the ArmMites, the PicoMite and loving it!
 
matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10627
Posted: 11:25am 11 Jul 2022
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  Quote  Does this caveat also apply to the 26 pin RPi 3.5" and 4" displays based on the ILI9481 (blue pcb and no SD card),


Those displays are wired as 16-bit parallel and have shift registers to mimic SPI. They don't have the same speed limitation but can't "BLIT" as the wiring doesn't support it. They use the "standard" ILI9341 driver not ILI9341IPS
 
Plasmamac

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Joined: 31/01/2019
Location: Germany
Posts: 596
Posted: 06:07pm 12 Jul 2022
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What is the best display for the pico ?
Plasma
 
matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10627
Posted: 06:30pm 12 Jul 2022
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  Quote  What is the best display for the pico ?


All the below support blit

With suitable adapter or wiring
ILI9488 with 680ohm resistor in MISO
ILI9341

Direct connect plug and play
https://www.waveshare.com/pico-restouch-lcd-2.8.htm

For high res and speed but high pin usage
Any SSD1963
 
Plasmamac

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Joined: 31/01/2019
Location: Germany
Posts: 596
Posted: 07:35pm 12 Jul 2022
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thx matherp
Plasma
 
Rickard5

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Joined: 31/03/2022
Location: United States
Posts: 463
Posted: 08:41pm 12 Jul 2022
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  matherp said  
Direct connect plug and play
https://www.waveshare.com/pico-restouch-lcd-2.8.htm


I so love my Waveshare display, best Drunk buy ever ;) but I just found This Wave Share Display does anyone know if it will work as well as the Pimaroni one, this one has a bonus joystick :)
I may be Vulgar, but , while I'm poor, I'm Industrious, Honest,  and trustworthy! I Know my Place
 
Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 8304
Posted: 09:12pm 12 Jul 2022
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Looks like it probably will. The 240x240 ST7789 with a CS pin is supported by MMBasic.
Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs
 
stanleyella

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Joined: 25/06/2022
Location: United Kingdom
Posts: 2681
Posted: 11:04pm 12 Jul 2022
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Newbie. ili9341 is fast and touch is accurate an it reads sd card.
 
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