Home
JAQForum Ver 20.06
Log In or Join  
Active Topics
Local Time 23:39 04 Oct 2022 Privacy Policy
Jump to

Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.

Forum Index : Microcontroller and PC projects : ILI9341 display 360x240 shows only 240x240

Author Message
rea23
Newbie

Joined: 16/09/2022
Location: Switzerland
Posts: 4
Posted: 01:19pm 21 Sep 2022
Copy link to clipboard 
Print this post

Hi, I am new here. Found MMBasic and it is great!

My first attempt is always a program that tests the raction time to a visual (LED) or audible (buzzer) signal.

First I used a 3.5 inch display from waveshare (ILI9488W) with touch and sdcard reader. Everything works very well on the 480x320 pixel display, including touch and sd-card.

Now i am trying the same on a display with an ILI9341 controller. It is the display shown on page 47 in the manual. The connections to the pi pico are the same as in the manual. Connections for touch and sd-card are not made at the beginning.

Option settings are:
OPTION SYSTEM SPI GP18, GP19, GP16
OPTION LCDPANEL ILI9341, L, GP15, GP14, GP13

The problem:
With "GUI TEST LCDPANEL" the test is runnig, but the display shows only a resolution of 240x240 instead of 320x240. However, the command "PRINT MM.HRES" correctly displays 320. I have checked all connections several times and also used other GPIO's, but it remains the same. I am almost sure that the display is ok, because when changing the orientation, the other side of the display is ignored respectively the old content in 120x240 remains in place. I also deleted the firmware (V.5.04.07) and installed it fresh on the pico. But that has also not changed anything.

If anyone has an idea, I would appreciate any help. Thanks in advance.



 
Volhout
Guru

Joined: 05/03/2018
Location: Netherlands
Posts: 1668
Posted: 01:33pm 21 Sep 2022
Copy link to clipboard 
Print this post

  rea23 said  Connections for touch and sd-card are not made at the beginning.


Your module has no touch controller (not soldered on the board).
I have no idea about the part of the display that is not working. Sorry. Maybe it is wiring (16MHz SPI clock ?), maybe it is the LCD supply voltage.
I assume you are using 5.07.04 software, not 5.04.07 ?

Volhout
If nothing goes right ... turn left
 
stanleyella

Guru

Joined: 25/06/2022
Location: United Kingdom
Posts: 366
Posted: 02:28pm 21 Sep 2022
Copy link to clipboard 
Print this post

  Volhout said  
  rea23 said  Connections for touch and sd-card are not made at the beginning.


Your module has no touch controller (not soldered on the board).
I have no idea about the part of the display that is not working. Sorry. Maybe it is wiring (16MHz SPI clock ?), maybe it is the LCD supply voltage.
I assume you are using 5.07.04 software, not 5.04.07 ?

Volhout


True, no xptouch chip wired.
I had a similar problem with one ili9341. Try powering the 5V display vcc from 3.3V. That worked for me. At some time I had soldered jumper J1 that bypasses the 3.3V reg but removed it but it gives similar display error at 5V. Powering the lcd VCC from 3.3 made it work.
 
Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 8243
Posted: 12:55am 22 Sep 2022
Copy link to clipboard 
Print this post

Hello - welcome to the forums.

@ Volhout & stanleyella - No touch controller chip, true, but his options don't show touch having been configured for this display and test, so it should not matter.  It WOULD matter if he had tried to enable and configure touch, without the chip present, as MMBASIC will not be getting the correct responses from the touch chip(cos it it not there), and that will probably corrupt the LCD display writes, or the LCD controller will be trying to respond to the touch data or something.

@ rea23 - as a test, ensure no touch is enabled(OPTION TOUCH DISABLE if you still have the option set, but are simply not using it), and permanently connect the LCD CS line to ground, then run the test again.  This will help prove if you have a floating CS line or perhaps a high-resistance CS line that is confusing the LCD controller etc.

If the LCD panel works fine with CS wired low, there is a CS line issue.  If you still see the same issue, then it's time to try another LCD module.  Not all LCD modules are the same.  MOST of them are, but you do occasionally see the odd one that does strange things, so to eliminate that, you need to try another LCD - if you have one.

  Volhout said  I assume you are using 5.07.04 software, not 5.04.07 ?

No, he says he IS using 5.04.07, so this might be his problem if there was an issue with the LCD driver in the earlier firmware?
Smoke makes things work. When the smoke gets out, it stops!
 
rea23
Newbie

Joined: 16/09/2022
Location: Switzerland
Posts: 4
Posted: 09:49am 22 Sep 2022
Copy link to clipboard 
Print this post

Hello and thank you all for your help.

Sorry for my typo. Of course I'm using 5.07.04. OPTION TOUCH is disabled. As recommended, I wired the CS line to ground. After that the whole display 320x240 is white illuminated. GUI TEST DISPLAYPANEL shows nothing. IF CS is connected back to GP13 the test works as before with 240x240 pixel. Therefore I'm ready to use the display with this resolution. And i will not buy such a display from the same seller again.
 
Bleep
Regular Member

Joined: 09/01/2022
Location: United Kingdom
Posts: 95
Posted: 10:02am 22 Sep 2022
Copy link to clipboard 
Print this post

Hi,
Have you tried changing the orientation in the option settings, just as an experiment? Might give you a bit more info on what might be going on. Though it certainly looks like a duff display.
Regards Kevin
 
rea23
Newbie

Joined: 16/09/2022
Location: Switzerland
Posts: 4
Posted: 01:14pm 22 Sep 2022
Copy link to clipboard 
Print this post

Hi,
Yes, I tried all four possible orientations like L, P, RL, RP. Change from L to RL shows missing 120 pixel on right or left side, but display remains with 240x240 in whole.
Regards, Hausi
 
stanleyella

Guru

Joined: 25/06/2022
Location: United Kingdom
Posts: 366
Posted: 06:40pm 22 Sep 2022
Copy link to clipboard 
Print this post

My experience on one ili9341. I recommend you do not assume a device works.
First image is it running from 5V as it should but there is a display problem.
image2 is it running at 3.3V ,I just swapped the lcd supply to 3.3V



Edited 2022-09-23 04:42 by stanleyella
 
Glen0
Regular Member

Joined: 12/10/2014
Location: New Zealand
Posts: 56
Posted: 10:18pm 22 Sep 2022
Copy link to clipboard 
Print this post

I had a problem with odd behaviour on what I had bought as ILI9341 but actually worked better with ILI9488 setting
Below is what Peter replied to my requested for help

"AFAIK there are no 3.2" ili9341 - try ILI9488"
Good luck
Sorry, haven't worked out how to send you a link to the thread I created for my issue.
Perhaps just search on my forum name. Glen0
 
rea23
Newbie

Joined: 16/09/2022
Location: Switzerland
Posts: 4
Posted: 12:47pm 28 Sep 2022
Copy link to clipboard 
Print this post

Hi, I have tested all the suggestions. In the end the hint with the other display driver was successful. When using the ILI9488 driver in portrait mode, the display shows all pixels in the range of 0-320 (not only 0-319) and 0-240. The display is currently running at 3.3 volts.

OPTION LCDPANEL 9488, PORTRAIT, GP15, GP14, GP13   (why portrait?)

The colors are inverted, i.e. you have to enter the inverse RGB values to display the desired color. This is a bit strange and I don't see the reason for it. But otherwise everything is fine so far.

Thanks again for the help, Hausi


 
Mixtel90

Guru

Joined: 05/10/2019
Location: United Kingdom
Posts: 2992
Posted: 01:17pm 28 Sep 2022
Copy link to clipboard 
Print this post

Some of these Chinese displays are decidedly odd. I sometimes wonder if they are built for particular customers then just thrown on the market anyway - simply labelled by what they think the display driver chip is because the board looks like someone else's. No attention paid as to how the chip is wired, of course. Why test them when you can sell them anyway? :)
Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs
 
disco4now

Guru

Joined: 18/12/2014
Location: Australia
Posts: 635
Posted: 01:23pm 28 Sep 2022
Copy link to clipboard 
Print this post

Have a look at this command from the manual.
POKE DISPLAY command [,data1] [,data2] [,datan]
This command sends commands and associated data to the display controller
for a connected display. This allows the programmer to change parameters
of how the display is configured. e.g. POKE DISPLAY &H28 will turn off
an SSD1963 display and POKE DISPLAY &H29 will turn it back on again.


This will allow you to send commands to configure the display. If you get the datasheet for the ILI9488 you should be able to send the command to change it for INVERTON (command 0x21)
Something like below.

POKE DISPLAY &H21,0  
or
POKE DISPLAY &H21,1
Edited 2022-09-28 23:25 by disco4now
 
stanleyella

Guru

Joined: 25/06/2022
Location: United Kingdom
Posts: 366
Posted: 03:45pm 28 Sep 2022
Copy link to clipboard 
Print this post

I can only suggest you get another ili9341, check your wiring is correct and try again.
The picomite non vga mmbasic works very well with a working ili9341.
Mine are 5 years old so guess they cost more now but if buying from ebay, test the device and if it does not work report back to ebay for a refund as not working. Do not accept buyer pays return postage. They will refund you without you posting the device back.
The ili9341 used in the manual must have worked. It is same as mine and 1 out of 4 works perfectly.  
 
Glen0
Regular Member

Joined: 12/10/2014
Location: New Zealand
Posts: 56
Posted: 11:23pm 29 Sep 2022
Copy link to clipboard 
Print this post

@rea23

Did you get the SD card working after changing to the 9488 setting? I never tried to get SD working on mine as other displays arrived and I continued with those. (actually damaged one of them, they are rather sensitive things)
Cheers
 
phil99

Guru

Joined: 11/02/2018
Location: Australia
Posts: 678
Posted: 12:03am 30 Sep 2022
Copy link to clipboard 
Print this post

"Did you get the SD card working after changing to the 9488 setting? "

That is a good way to determine if it is an ILI9488 chip. If an SD card will only work with shared SPI when there is a 680R or switching transistor in between LCD SDO(MISO) and Pico MISO.


Edit
Attempted to see what "normal" control register values look like but just get 0 0 for everything.
Perhaps there is an offset required?

> for n=0 to 220 :? Peek DISPLAY n,,hex$(n) :next
0 0 0          0
0 0 1          1
0 0 2          2
0 0 3          3
0 0 4          4
.
.
.
0 0 215                D7
0 0 216                D8
0 0 217                D9
0 0 218                DA
0 0 219                DB
0 0 220                DC
>
Edited 2022-09-30 14:01 by phil99
 
Print this page


To reply to this topic, you need to log in.

© JAQ Software 2022