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Author Topic: Python 3 cant find RPi.GPIO  (Read 1614 times)

Offline johnwmcc

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Re: Python 3 cant find RPi.GPIO
« Reply #15 on: December 12, 2018, 10:41:30 AM »
Thank  you again, Rich.

Busy most of this evening but will follow up either late tonight or some time tomorrow

Offline johnwmcc

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Re: Python 3 cant find RPi.GPIO
« Reply #16 on: December 12, 2018, 10:55:03 AM »
Tried that, found config.txt, uncommented hdmi_force_hotplug=1, and rebooted.

Sorry, but no difference - still the same low resolution.

Will follow up on other suggestions late tonight or tomorrow - have to stop now.

Offline johnwmcc

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Re: Python 3 cant find RPi.GPIO
« Reply #17 on: December 12, 2018, 04:55:50 PM »
Still stuck.

Found and edited context.txt. Can't change the resolution that way as far as I can see.

Tried uncommenting in turn:
no display
hdmi_force_hotplug=1
hdmi_safe

Resolution stubbornly stuck at low or very low.

Searched Apps for 'vnc' and get only two results - one for tigervnc viewer, and x11vnc as the only server available in .tcz form.

Are there other vnc servers that will run on piCore? If so, where can one find them?

Tried tigervnc viewer 64bit on Windows.

The program has options to set the display resolution directly and also to 'resize remote session to local window'.

Tried two different resolutions - both 1024x768 (the default) and 1920x1080. Also tried 'resize..' to local window.

Neither works to enlarge the remote window - it just scales up the low res screen to a bigger view size, but gives no more effective resolution.

Anything else to try?

I've looked on this page: http://www.karlrunge.com/x11vnc/x11vnc_opts.html

It suggests using either  -geometry widthxheight or equivalently -scale widthxheight parameters when starting x11vnc server.

This doesn't change the resolution at the remote end, and just scales it up to that size on the viewer screen.

I notice that it does say at the top 'allow VNC connections to real X11 displays' (my emphasis).

Does this mean it can't set a resolution when running headless (no 'real' display)?

It was all working fine when there was a real monitor with Full HD resolution plugged in, but that isn't a realistic option for the intended end use.

Can anyone offer any further help before we just give up on this distro?

It is all proving an order of magnitude more difficult than we expected or can cope with.

Perhaps I should start a new topic for the resolution change - it seems to be an unsolved problem?
« Last Edit: December 12, 2018, 04:57:43 PM by johnwmcc »

Offline johnwmcc

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Re: Python 3 cant find RPi.GPIO
« Reply #18 on: December 12, 2018, 05:22:48 PM »
Just before giving up for the night, I tried once more.

Edited config.txt to uncomment hdmi_safe=1 and no display. Commented out again #hdmi_force_hotplug=1

Also uncommented and changed the framebuffer parameters, first to the default 1280x720 then 1920x1080.

This has definitely improved things, but I am now not quite certain which of the changes is taking full effect after I restarted x11vnc with the following command line:

x11vnc -display :0 -many -geometry 1920x1080

That seems to be working well enough to let us get on with debugging the python scripts, which was the original intention of this whole exercise.

Thanks for help that has pointed us in the right directions even if sometimes up apparently dead ends. Without that feedback from you we'd have had to give up days ago.


Online Rich

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Re: Python 3 cant find RPi.GPIO
« Reply #19 on: December 12, 2018, 07:14:21 PM »
Hi johnwmcc
Quote
This has definitely improved things, but I am now not quite certain which of the changes is taking full effect after I restarted x11vnc ...
I suspect it was the frame buffer parameters that made the difference. I saw a post from 2014 on the raspberry pi forum
that said  hdmi_force_hotplug=1  should be commented out. It went on to say to run:
Code: [Select]
fbset -g 1920 1080 1920 1080 16prior to starting X.