Peter,

The ILI9381 driver works but the screen is dark-to-light from the left. The BACKLIGHT command doesn't seem to do much.

Also, I cannot get the FORMATBOX graphic to work with the 2.8 inch display.

All the other advanced graphics command seem to work.

  Quote  

The ILI9381 driver works but the screen is dark-to-light from the left. The BACKLIGHT command doesn't seem to do much.

Try ILI9481

  Quote  

Also, I cannot get the FORMATBOX graphic to work with the 2.8 inch display.

Works for me:



There is a bug causing a reset related to format box after leaving the program and editing or re-running but the basic functionality seems to work
Edited 2021-10-17 05:01 by matherp

I just get an interesting promo from Elektor ....
waveshare evaluation board for raspberry pi pico
The LCD , SD Card , Audio , etc... made it a good starting board.
You just have to add the pico on it ;)

The main problem with the Waveshare boards (and some others) is that unless you use stackable female headers on the pico (or use an expansion board of some sort) there's no-where to connect Pico pins to anything else. The picture in that link shows it very well - you can't connect anything to the Pico if you use the normal male pins. This was something I worked hard at when I did my PicoMite Backpack pcb. :)
Edited 2021-10-17 07:20 by Mixtel90

  Mixtel90 said  

The main problem with the Waveshare boards (and some others) is that unless you use stackable female headers on the pico (or use an expansion board of some sort) there's no-where to connect Pico pins to anything else. The picture in that link shows it very well - you can't connect anything to the Pico if you use the normal male pins. This was something I worked hard at when I did my PicoMite Backpack pcb. :)

That's weird, I had just found these and then I came here.

  Mixtel90 said  

The main problem with the Waveshare boards (and some others) is that unless you use stackable female headers on the pico (or use an expansion board of some sort) there's no-where to connect Pico pins to anything else. The picture in that link shows it very well - you can't connect anything to the Pico if you use the normal male pins. This was something I worked hard at when I did my PicoMite Backpack pcb. :)

What about using these with longer legs?!

  matherp said  

  Quote  

The ILI9381 driver works but the screen is dark-to-light from the left. The BACKLIGHT command doesn't seem to do much.

Try ILI9481

...

Is the item you are talking about exactly this one (circuit diagram)?

  Poppy said  

  matherp said  

  Quote  

The ILI9381 driver works but the screen is dark-to-light from the left. The BACKLIGHT command doesn't seem to do much.

Try ILI9481

...

Is the item you are talking about exactly this one (circuit diagram)?

Actually now I am a little more confused.

Is there any important difference between these 2 boards concerning compatibility?

Pico_Eval-Board

Pico-Res-Touch

... or will both work without any problems?

  Quote  

Is there any important difference between these 2 boards concerning compatibility?

Both of them wire the display in parallel and then use shift registers to create a SPI I/F (hence all the extra chips). This does not present the same as a normal SPI connected ILI9488 and it appears from cdeagle doesn't work. The only driver I have ever written to use this sort of connection is the ILI9481 driver which may or may not be compatible.

I don't have one of these displays so am unable to test and/or get it working.

  Poppy said  

  Mixtel90 said  

The main problem with the Waveshare boards (and some others) is that unless you use stackable female headers on the pico (or use an expansion board of some sort) there's no-where to connect Pico pins to anything else. The picture in that link shows it very well - you can't connect anything to the Pico if you use the normal male pins. This was something I worked hard at when I did my PicoMite Backpack pcb. :)

What about using these with longer legs?!

Those are the stackable female headers I was on about. If you fit them to a Pico you can plug it into anything and still be able to connect to it - you just have to be careful about which pins are already used. I did my first one like that - it gives you a row of holes back on your breadboard and allows you to make "hats" for it. A bit more expensive than the ordinary pins though.

------------

I'm not sure I like that idea of synthesized SPI on those displays. It's rather like creating a new serial interface that's neither I2C nor true SPI. Just checking ebay for a 10ft barge pole to keep them away.

cdeagle

Please try the attached



PicoMiteV5.07.00b29.zip



Use the option

OPTION LCDPANEL ILI9488W,GP8,GP15,GP9,GP13
Edited 2021-10-17 18:29 by matherp

Peter,

Results from b29. Asterisk is text that TBS doesn't like.

> option system spi gp10,gp11,gp12
> option lcdpanel ILI9488W,gp8,gp15,gp9,gp13
Error : Orientation
> option list
OPTION SYSTEM SPI GP10,GP11,GP12
OPTION LCDPANEL ST7789Read,  *,NULL,NULL,NULL
> text 10,10, "testing"
Error : Display not configured

Sorry missed the orientation in the command

option lcdpanel ILI9488W,L,gp8,gp15,gp9,gp13

and found something else as well - new version in a minute
Edited 2021-10-17 19:31 by matherp

Please do OPTION RESET before loading this

PicoMiteV5.07.00b29.zip


OPTION SYSTEM SPI GP10,GP11,GP12
OPTION LCDPANEL ILI9488W, LANDSCAPE,GP8,GP15,GP9,GP13

Peter,

In order to turn off the grey-to-white display of the 9488, I have to set BACKLIGHT 5.

Then I cannot see any graphics on the display. If I leave BACKLIGHT 100, the display seems to work, at least simple text and GUI TEST LCDPANEL. Of course it's hard to read.

Here's a photo of the display with BACKLIGHT 10 and GUI TEST LCDPANEL running.



David

Just to confirm, the new ILI9488W driver is working but the backlight is overpowering?

Try this version (last try possible without a display)


PicoMite.zip
Edited 2021-10-17 20:20 by matherp

Peter,

ILI9488W driver is working. Latest uf2 has reduced the display backlight almost completely. Still some on the right side of the display. Photo attached.



David

This is now using the initialisation specified by Waveshare in their demo code so nothing more I can do. The rest of the light bleed is presumably just down to the way the display is made. I'll post this version as a new beta.

Thanks for your help Peter.

It doesn't appear to be a very even backlight at all. Changing the brightness will be a compromise at best - it's the way the display is assembled. Either that or there's a bank of LEDs down the dark side that isn't working.