Calibration needed on a waveshare 3,5 inch display

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
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Pa3fbx
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Joined: Fri Oct 16, 2020 1:08 pm

Calibration needed on a waveshare 3,5 inch display

Post by Pa3fbx » Fri Oct 16, 2020 1:22 pm

Hi Guy's,
New on the forum but active on the qo100..
Playing with portsdown to invesigate all the goodies..

My problem today is that i can not get the touchscreen off a waveshare 3,5 version A to work correctly.
I have struggled over a week with it and it seems that the touchscreen is not standard.
I have installed it on Portsdown 2020 with a Pi3B.

Made twice a new installation after screwingup the lot...

Now for testing the display i installed a windows version and again the calibration was off...
And when i mean off its swapped Top and Bottem off...

Than i found a calibration tool for the windows adn got it pretty good...

got the data but can't find where to put this in portsdown...
Due to the compleet mis alignment i cannet get into the touchscreen tool inside the portsdown menues...

So.. how to calibrate true the putty and menu in putty...

Thanks for your help in advance...

Benno

G8GKQ
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Re: Calibration needed on a waveshare 3,5 inch display

Post by G8GKQ » Fri Oct 16, 2020 1:46 pm

Hi Benno

Sounds like your display is behaving like a Waveshare "B".

Try going to the console menu (after logging in by ssh) and then go to "Display Type" and select the display Waveshare B (remember to press the spacebar to select), and then rebooting. It should turn the picture round....

Full details of that procedure here: https://wiki.batc.org.uk/Console_mode

Dave, G8GKQ

Pa3fbx
Posts: 229
Joined: Fri Oct 16, 2020 1:08 pm

Re: Calibration needed on a waveshare 3,5 inch display

Post by Pa3fbx » Fri Oct 16, 2020 2:30 pm

Thanks dave...
Sorry but no...
I,ve tryied your idea..
waveshare 3,5 ver B gives me a blank display and the touchscreen still is swapped...
by now i can confirm that the X and Y are swapped and rotated 180 ...
so for instance the TX button is bottom right and the M2 is right side abbove tghe middle..
got at the calib option but sadly it tells me the touch is to fare out off the crosshair and than falls back...

x and y outputs in putty give me for:
tx button x=3416 y=997
M3button x=563 y=860
Store preset x=592 y=3523
and preset 1= x=3592 y=3402

so conclusion bottom left is max and top right side is min values...

any other idea's...

benno

G8GKQ
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Re: Calibration needed on a waveshare 3,5 inch display

Post by G8GKQ » Fri Oct 16, 2020 2:48 pm

Benno

Please could you post a photo of the reverse (component and connector) side of your screen?

Thanks

Dave

Pa3fbx
Posts: 229
Joined: Fri Oct 16, 2020 1:08 pm

Re: Calibration needed on a waveshare 3,5 inch display

Post by Pa3fbx » Fri Oct 16, 2020 2:57 pm


G8GKQ
Site Admin
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Re: Calibration needed on a waveshare 3,5 inch display

Post by G8GKQ » Fri Oct 16, 2020 3:24 pm

OK Benno

Your problem is that you do not have a genuine Waveshare Type A Display. It is a some sort of (poor) copy.

The genuine display is marked like this: https://www.waveshare.com/product/displ ... -lcd-a.htm

You could go into the c code (rpidatv/src/rpidatvtouch.c) modify it to work and then recompile, but I would suggest that it is not worth the effort.

We had lots of similar problems when we started the project 3 years ago. If you have room, I would suggest that you replace it with the Raspberry Pi Foundation 7 inch display https://www.raspberrypi.org/products/ra ... h-display/ then you can use it to watch smooth video from the streamer or (with a MiniTiouner) as a DATV receiver.

Dave, G8GKQ

Pa3fbx
Posts: 229
Joined: Fri Oct 16, 2020 1:08 pm

Re: Calibration needed on a waveshare 3,5 inch display

Post by Pa3fbx » Fri Oct 16, 2020 5:59 pm

Your problem is that you do not have a genuine Waveshare Type A Display. It is a some sort of (poor) copy....

Hi Dave,

I was afraid this was the case.
Got it localy in the netherlands and not on ebay but even than there is no garantee...

I could go for a different display but as portsdown is currently just an experiment for me i will not invest more..
i have pluto with OBS running and am looking mainly for the RX features...
I am also looking at ryde witch is better for my needs alltough thats not ready by far...

I will look into a software solution now and if its gets to much work i leave the 3,5 display on the shelf for a different project...

Thanks so far...

Benno

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