samalpramod
Posts: 2
Joined: Fri Aug 30, 2019 11:50 am

Display not working on Raspberry Pi 3 XPT 2046 3.5 inch display

Fri Aug 30, 2019 12:01 pm

Hi,
I am new to this forum and beginner. I had a Raspberry Pi3 device having Ubuntu 18.04 LTS server. A 3.5 inch RPi Display is attached to the Raspberry Pi device. But nothing is getting displayed on the LCD device which has XPT2047 touch controller. I had searched a lot on the Google and could not find anything that will help me to display data on the LCD screen. Please help me to resolve the issue.

Thanks
Pramod

W. H. Heydt
Posts: 10914
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Display not working on Raspberry Pi 3 XPT 2046 3.5 inch display

Fri Aug 30, 2019 3:16 pm

I would suggest a careful look at either the manufacturers or the retailers (may be the same) web sites. If they don't have set up directions, you may be out of luck. My experience with GPIO-mounted 3.5" displays (Neosec and Adafruit) is that you need to modify cmdline.txt and config.txt for the displays.

samalpramod
Posts: 2
Joined: Fri Aug 30, 2019 11:50 am

Re: Display not working on Raspberry Pi 3 XPT 2046 3.5 inch display

Wed Sep 04, 2019 1:20 pm

I too using GPIO mounted LCD touch screen with 3/5" RPi Display(RoHS). Could you please let me know the changes you made to config.txt and command.txt.

Thanks
Pramod

W. H. Heydt
Posts: 10914
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Display not working on Raspberry Pi 3 XPT 2046 3.5 inch display

Wed Sep 04, 2019 2:09 pm

samalpramod wrote:
Wed Sep 04, 2019 1:20 pm
I too using GPIO mounted LCD touch screen with 3/5" RPi Display(RoHS). Could you please let me know the changes you made to config.txt and command.txt.

Thanks
Pramod
The instructions are linked from this http://www.neosecsolutions.com//product ... 8&cPath=20 The config.txt and cmdline.txt are steps 11 and 12. NOTE: These are for the Neosec 3.5" touchscreen. Your vendor *should* have comparable information for their product. If they don't, I would drop that vendor like a hot potato.

wh7qq
Posts: 1330
Joined: Thu Oct 09, 2014 2:50 am

Re: Display not working on Raspberry Pi 3 XPT 2046 3.5 inch display

Wed Sep 04, 2019 11:22 pm

W. H. Heydt wrote:
Wed Sep 04, 2019 2:09 pm

The instructions are linked from this http://www.neosecsolutions.com//product ... 8&cPath=20 The config.txt and cmdline.txt are steps 11 and 12. NOTE: These are for the Neosec 3.5" touchscreen. Your vendor *should* have comparable information for their product. If they don't, I would drop that vendor like a hot potato.
It appears that more than one chipset/configuration are on the market. The MHS 35 display seems to use a different chipset for the display and the GPIO pin usage is somewhat different. There is no RTC. I recently purchased such a display from Kuman/Amazon (https://www.amazon.com/gp/product/B07P7 ... UTF8&psc=1) and I was able to follow the instructions and get a pretty display of the desktop. They have a nice set of instruction pages online in addition to the tiny "Quickstart" sheet included with the display. I initially had problems with getting readable text on the LXTerminal (cli) because it was too @#$! small for my old eyes.

Then, I went ahead and used a fresh copy of Buster and my normal HDMI display to get it set up and working properly. At that point, "raspi-config" showed a 720x480 default display which I reset to 320x480 and that helped some but a bit of further fiddling with "LXTerminal" Preferences increased the text size to 12 pts and bold. On reboot with the 3.5" display attached, all was happy.

The moral of the story is to not follow the "Quickstart" as written for the MHS 3.5. Start the setup with no 3,5"...just a normal monitor like a 21" HDMI type or a TV and get the RPi set up with that. Once setup to your satisfaction (including font size), go back to the "Quickstart" and do:

Code: Select all

sudo rm -rf LCD-show
git clone https://github.com/goodtft/LCD-show.git
chmod -R 755 LCD-show
sudo ./MHS35-show
And it all worked great!

This was done on an RPi3 with a Logitech K400 Keyboard/Mouse and the display mentioned above and the latest Raspbian Buster. (7/10).

Also, note that Etcher does not "see" the downloaded files until ".zip" is added to the end of the name...frustrating until you realize that.

W. H. Heydt
Posts: 10914
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Display not working on Raspberry Pi 3 XPT 2046 3.5 inch display

Thu Sep 05, 2019 1:18 am

wh7qq wrote:
Wed Sep 04, 2019 11:22 pm
W. H. Heydt wrote:
Wed Sep 04, 2019 2:09 pm

The instructions are linked from this http://www.neosecsolutions.com//product ... 8&cPath=20 The config.txt and cmdline.txt are steps 11 and 12. NOTE: These are for the Neosec 3.5" touchscreen. Your vendor *should* have comparable information for their product. If they don't, I would drop that vendor like a hot potato.
It appears that more than one chipset/configuration are on the market.
Hence my note that it applied to the displays I use and the OP should seek out comparable data from his supplier. The link I posted should be considered no more than a sample of what sort of things one might need to do, not a definitive solution for some random display.

Return to “General discussion”