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by il_diavolo
Thu Aug 25, 2022 9:03 pm
Forum: Official Display
Topic: Official 7" screen white lines and goes black on Pi 3 B
Replies: 8
Views: 581

Re: Official 7" screen white lines and goes black on Pi 3 B

I'm no expert but mine does that if the voltage to the screen drops too low. I cured it by upgrading the power supply.
by il_diavolo
Mon Apr 11, 2022 9:18 pm
Forum: General discussion
Topic: Code works in Windows but not Raspberry pi (opencv)
Replies: 3
Views: 371

Re: Code works in Windows but not Raspberry pi (opencv)

I've been struggling with this for some time. After extensive Googling it is clear that there is a bug in OpenCV (4.5.4 in my case) when used with Raspberry Pi and Bullseye. (32 bit, don't know about the 64 bit version). As far as I can find, despite trying many of the suggestions on Stack Overflow ...
by il_diavolo
Sat May 15, 2021 9:04 pm
Forum: General discussion
Topic: Machine Vision using raspberry pi (3B+)
Replies: 13
Views: 897

Re: Machine Vision using raspberry pi (3B+)

Sorry, slightly off topic, but if one installs cv2 as suggested by Gordon77 "sudo apt install python3-opencv" does that include the "not free" SIFT and SURF methods? For a use example, "detector = cv2.xfeatures2d.SURF_create(100)"
by il_diavolo
Sat Feb 27, 2021 10:12 pm
Forum: Beginners
Topic: Run two programs simultaneously
Replies: 4
Views: 960

Re: Run two programs simultaneously

I would have thought that threading or multiprocessing is the answer. My robot runs with several threads and multiprocesses "simultaneously" processing compass, cameras, rotary encoders, text to speech etc..
by il_diavolo
Sat Feb 20, 2021 4:09 pm
Forum: General discussion
Topic: Terminal location on desktop
Replies: 4
Views: 735

Re: Terminal location on desktop

Thanks both of you for your input. I installed "Xterm" and it works just as you said. Unfortunately the default font is all but unreadable on the small screen and if I choose a "large" font version the terminal window is too big. Also my original question remains unanswered, why ...
by il_diavolo
Thu Feb 18, 2021 10:53 pm
Forum: General discussion
Topic: Terminal location on desktop
Replies: 4
Views: 735

Terminal location on desktop

I control my robot using a portable Pi 3B with an official 7" touchscreen which connects via VNC to the robot which is set up as an access point. Both the 3B and the Pi4B 2G in the robot have the screen sizes set at 800 x 480 in config.txt, the official screen resolution. Both Pi's are using re...
by il_diavolo
Tue Feb 02, 2021 10:30 pm
Forum: Official Display
Topic: How do I enable multi touch?
Replies: 3
Views: 1819

Re: How do I enable multi touch?

Rant over. Sorry about the rant. Never write on a forum after a bottle of wine! However it prompted me to look harder for a right click solution and after intense Googling I'm happy to report that the recipe from this link https://fmirkes.github.io/articles/20190827.html works a treat. I'm afraid I...
by il_diavolo
Sat Jan 16, 2021 10:49 pm
Forum: Official Display
Topic: How do I enable multi touch?
Replies: 3
Views: 1819

Re: How do I enable multi touch?

I'd be happy with a right click function that doesn't require all kinds of edits etc to get. And that won't get broken next time you upgrade the OS. Here, here. (or is it hear, hear?) I had "twofing"" working on my 3B "PortaPi" for a couple of years but then one of the rece...
by il_diavolo
Sat Oct 31, 2020 10:24 pm
Forum: Official Display
Topic: Multiple questions (right click, border and what DE)
Replies: 2
Views: 852

Re: Multiple questions (right click, border and what DE)

Hi, I have just purchased my official display and it works great for my portable setup However I have some questions How can I activate right click as I (to be honest) can't be bothered to read 76 posts of the how to guide, I have tried the initial post with no progress. How can I set a border for ...
by il_diavolo
Mon Oct 12, 2020 9:26 pm
Forum: Beginners
Topic: Gertboard connection to Pi4
Replies: 1
Views: 214

Re: Gertboard connection to Pi4

I used a pair of male/female 26 pin plugs with a ribbon cable to the Gertboard. I didn't go straight off the Pi's pins but via a PiBorg "TriBorg" expander board plugged onto the Pi4 (originally on a Pi2). The plugs and ribbon I bought in Maplin a few weeks before they went bust!
by il_diavolo
Thu Aug 20, 2020 9:13 pm
Forum: Automation, sensing and robotics
Topic: Map making from Lidar?
Replies: 2
Views: 880

Re: Map making from Lidar?

Thanks for the link.
It seems that the simple answer to my question is that it's not simple!
by il_diavolo
Wed Aug 19, 2020 9:28 pm
Forum: Automation, sensing and robotics
Topic: Map making from Lidar?
Replies: 2
Views: 880

Map making from Lidar?

Is it possible to create a vectorised map from the 2D point cloud generated by a Slamtec RPLidar?
by il_diavolo
Mon Aug 17, 2020 9:32 pm
Forum: General discussion
Topic: RPI3 B+ & 7" Touchscreen & Camera Module off battery???
Replies: 2
Views: 169

Re: RPI3 B+ & 7" Touchscreen & Camera Module off battery???

My "PortaPi" consists of a Pi 3B, an official 7" screen and a V1 camera all mounted in a "Tupperware" type box. Both the Pi and the screen are powered by a single battery pack of 8 no. AA rechargeable batteries with a separate 5v feed to screen and Pi from two Piborg "B...
by il_diavolo
Wed Jul 08, 2020 9:14 pm
Forum: Python
Topic: Python loop help and if statement? help PLEASE
Replies: 21
Views: 1129

Re: Python loop help and if statement? help PLEASE

Thanks mstrudwick for making me smile! It's a great feeling when one's code works.
by il_diavolo
Wed May 20, 2020 9:06 pm
Forum: Troubleshooting
Topic: PIGPIO encoder script affected by other threads
Replies: 5
Views: 772

Re: PIGPIO encoder script affected by other threads

Idahowalker, thanks for the reply. Your code is a bit daunting at first sight but I'll work my way through it. Are you saying that one can dedicate a core to a particular task with multi tasking? I always aim to learn at least one new thing a day.
by il_diavolo
Wed May 20, 2020 4:15 pm
Forum: Troubleshooting
Topic: PIGPIO encoder script affected by other threads
Replies: 5
Views: 772

PIGPIO encoder script affected by other threads

My robot is a much modified DiddyBorg with a Pi4B2G running up to date Raspbian Buster and Python 3 scripts. There are two simple rotary encoders mounted on the left and right front wheels and these are decoded using the encoder script from the PIGPIO library, obviously there are two instances runni...
by il_diavolo
Sat Mar 28, 2020 10:01 pm
Forum: General discussion
Topic: Posting Images?
Replies: 11
Views: 940

Re: Posting Images?

MB?
by il_diavolo
Thu Mar 26, 2020 10:31 pm
Forum: Advanced users
Topic: 2D Indoor tracking for autonomous car
Replies: 6
Views: 818

Re: 2D Indoor tracking for autonomous car

I'm currently doing something similar with my robot. I am using a magnetometer to get compass bearings and rotary encoders on the wheels to measure distance. I have had good results by driving the robot along the required course and recording the distance and bearing at 25mm intervals. Then I place ...
by il_diavolo
Thu Mar 26, 2020 10:05 pm
Forum: General discussion
Topic: what happened to the raspberry pi 4 1GB?
Replies: 23
Views: 4060

Re: what happened to the raspberry pi 4 1GB?

That parable was the main reason I became an atheist. So unfair.
by il_diavolo
Thu Feb 13, 2020 10:42 pm
Forum: Python
Topic: pigpio_encoder not installing on Buster
Replies: 19
Views: 2127

Re: pigpio_encoder not installing on Buster

I can only say "I got it to work"! Once I realised that the "rotary.encoder" I was trying to import, thinking it was installed with pigpio, was actually the example code which needed importing as a module (put it in the same folder or make sure it's in the Python path). In fact I...
by il_diavolo
Thu Feb 13, 2020 10:22 pm
Forum: General discussion
Topic: How to install OpenCV on Raspberry Pi?
Replies: 6
Views: 16789

Re: How to install OpenCV on Raspberry Pi?

Have you tried renaming "cv2.cpython-37m-arm-linux-gnueabihf.so" to "cv2.so"? I'm sure that's what I did.
by il_diavolo
Fri Jan 24, 2020 10:23 pm
Forum: Troubleshooting
Topic: window is too big for the screen
Replies: 2
Views: 2295

Re: window is too big for the screen

A work around is to hold the "alt" key down on the keyboard and move the window on the screen with your finger until you can see the area you need. It also works with the Florence on-screen keyboard. Sorry, I can't give you a resizing solution. I have the same problem with the VNC Viewer w...

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