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by knute
Fri Jan 25, 2019 11:28 pm
Forum: Java
Topic: Desktop indicators bleed through JavaFX
Replies: 19
Views: 5190

Re: Desktop indicators bleed through JavaFX

I haven't done much with FX on the Pi because it didn't work very well for quite a while. I know you can use Aleksy Shipilev's (https://builds.shipilev.net/openjdk-jdk11/) arm build of openJDK11 and gluon's JavaFX 11 early access for the arm. I don't know what repo has 11, when I look I just see ope...
by knute
Fri Jan 25, 2019 2:02 am
Forum: Advanced users
Topic: Virtual com port drivers?
Replies: 9
Views: 1182

Re: Virtual com port drivers?

Thanks for all the information. I got the sensor and plugged it in and it creates the /dev/ttyUSB0 device. I even got their SDK to compile and run some test programs on the Pi.

Thanks again for all the help.
by knute
Fri Jan 25, 2019 1:59 am
Forum: Java
Topic: Desktop indicators bleed through JavaFX
Replies: 19
Views: 5190

Re: Desktop indicators bleed through JavaFX

An update on my previous post. This worked great for graphics, but was crashing with a SEGFAULT when trying to play a media clip. Based on another post, I forced a reinstall and that seems to have fixed it. sudo apt-get install --reinstall -y openjdk-8-jre-headless openjdk-8-jre openjfx It does see...
by knute
Sun Jan 20, 2019 12:30 am
Forum: Advanced users
Topic: Virtual com port drivers?
Replies: 9
Views: 1182

Re: Virtual com port drivers?

Thanks everybody for all the information. I'm supposed to have the sensor next week to play with. I'm sure I will have more question later.

Thanks!
by knute
Sun Jan 20, 2019 12:27 am
Forum: Java
Topic: Desktop indicators bleed through JavaFX
Replies: 19
Views: 5190

Re: Desktop indicators bleed through JavaFX

casete wrote:
Sat Jan 19, 2019 4:04 pm
I'd be really interested to know what I would need to do to get my Pi set up properly with OpenJFX. Looking forward to hearing more!
If you are using openjdk8 then just: sudo apt install openjfx

that's it.
by knute
Sat Jan 19, 2019 3:10 am
Forum: Java
Topic: Desktop indicators bleed through JavaFX
Replies: 19
Views: 5190

Re: Desktop indicators bleed through JavaFX

You might give OpenJFX a try, it's in the repository. Tomorrow when I'm back in front of my Pi I'll post the code for a simple app and a screen shot. That may explain what's up.
by knute
Sat Jan 19, 2019 3:05 am
Forum: Advanced users
Topic: Virtual com port drivers?
Replies: 9
Views: 1182

Re: Virtual com port drivers?

So the /dev entries are created when the device is plugged in? That assumes a smart device yes, that tells the Pi what it is? Sorry to be so dense but this isn't something I have any familiarity with.
by knute
Fri Jan 18, 2019 8:55 pm
Forum: Java
Topic: Desktop indicators bleed through JavaFX
Replies: 19
Views: 5190

Re: Desktop indicators bleed through JavaFX

Maybe I should ask what Java and JavaFX you are using? And what version of Raspbian? I know that some early versions would only run through the framebuffer. I've run a few JavaFX programs under OpenJDK and OpenJFX and they window just like a Swing app does. Can you post your code or is it super secr...
by knute
Fri Jan 18, 2019 8:50 pm
Forum: Advanced users
Topic: Virtual com port drivers?
Replies: 9
Views: 1182

Re: Virtual com port drivers?

COM ports are a windows construct. USB-serial devices appear as tty's (terminal devices) as /dev/ttyUSB0 - /dev/ttyUSBx. You can access them through various file stream utilities (i.e. echo "blah" > /dev/ttyUSB0 results in blah being transmitted on the wire) or via system calls in your own programs...
by knute
Thu Jan 17, 2019 9:50 pm
Forum: Advanced users
Topic: Virtual com port drivers?
Replies: 9
Views: 1182

Virtual com port drivers?

Are there virtual com port drivers for serial to USB devices?

Thanks!
by knute
Thu Jan 17, 2019 9:47 pm
Forum: Java
Topic: Desktop indicators bleed through JavaFX
Replies: 19
Views: 5190

Re: Desktop indicators bleed through JavaFX

Can you make the background opaque on your app?
by knute
Thu Jan 17, 2019 4:04 am
Forum: Beginners
Topic: UART on Pi3B & 3B+ ?
Replies: 5
Views: 728

Re: UART on Pi3B & 3B+ ?

klricks wrote:
Wed Jan 16, 2019 4:24 am
knute wrote:
Wed Jan 16, 2019 3:53 am
.....The second is, is there any hardware flow control available (RTS,CTS)?
If UART 1 is used then RTS and CTS is available.

(UART 0 has no flow control)
Is there documentation somewhere on which pins for RTS/CTS and on the port in general?

Thanks.
by knute
Thu Jan 17, 2019 4:02 am
Forum: Beginners
Topic: UART on Pi3B & 3B+ ?
Replies: 5
Views: 728

Re: UART on Pi3B & 3B+ ?

I ran a RPi to Arduino Due serial communication at 230400 without issues. I did not use any hardware flow control. I used software flow control. I used "<" to start a message and ">" to end a message sentence for each direction. I'd ignore bytes till the data stream hit a ">" and keep collecting da...
by knute
Wed Jan 16, 2019 3:53 am
Forum: Beginners
Topic: UART on Pi3B & 3B+ ?
Replies: 5
Views: 728

UART on Pi3B & 3B+ ?

I've got a project coming that needs to communicate via serial and I have no experience with Pis and the serial port. Fortunately it is 3.3v and won't require any level conversion. My first question is about baud rates and buffers. Can the Pi receive data at 115200 baud and clear the buffer fast eno...
by knute
Wed Jan 09, 2019 3:59 pm
Forum: Networking and servers
Topic: Setting up "basic" mail
Replies: 3
Views: 994

Re: Setting up "basic" mail

mail is part of the mailutils package (and I think some other). It delivers mail to a user or to a mail transfer agent. You need to install the rest of the mail system however, something to collect and deliver the mail. I really like sendmail for that but you will get plenty of other suggestions. I'...
by knute
Tue Jan 08, 2019 2:25 am
Forum: Graphics, sound and multimedia
Topic: Raspberry Pi two way communication
Replies: 2
Views: 2023

Re: Raspberry Pi two way communication

And this simple intercom program written in Java for the Pi at http://pi.knutejohnson.com.
by knute
Sun Jan 06, 2019 8:20 pm
Forum: Beginners
Topic: how install openjdk?
Replies: 8
Views: 11585

Re: how install openjdk?

I got around that by uninstalling the installed Java first. Then install openjdk. I'm not sure but I think it is a problem with the installer looking in the wrong place for certificates (but I could definitely be wrong).
by knute
Sun Dec 30, 2018 10:59 pm
Forum: Python
Topic: Automatic opening of a picture
Replies: 6
Views: 846

Re: Automatic opening of a picture

Well it would be easy enough to modify that program to display 4 images and then you wouldn't have to go get them.
by knute
Sun Dec 30, 2018 3:27 am
Forum: Python
Topic: Automatic opening of a picture
Replies: 6
Views: 846

Re: Automatic opening of a picture

I'm not much of a Python programmer but in Java reading an image file and displaying it is fairly easy. Every 10 seconds this program reads the file Desktop\image.jpg and displays it scaled and centered in a frame. If you resize the frame the image will resize. Just copy your dated file to another f...
by knute
Mon Dec 24, 2018 10:00 pm
Forum: General discussion
Topic: Create scrolling news ticker nu.nl
Replies: 2
Views: 342

Re: Create scrolling news ticker nu.nl

I've programmed news tickers before in Java but on faster computers with much faster video. I'm not sure that a Pi has quite enough oomph to display a ticker. How fast do you need it to tick?
by knute
Thu Dec 13, 2018 4:29 pm
Forum: Camera board
Topic: Raspixxx camera software - changes
Replies: 6
Views: 853

Re: Raspixxx camera software - changes

Pardon my ignorance but how does one get this software? I would like to try it out. As @JamesH mentions above: it's not in the regular repo, so you have to get the source from the 'userland' git repository and then build it. The repo is at https://github.com/raspberrypi/userland (use 'git clone' or...
by knute
Thu Dec 13, 2018 3:39 pm
Forum: Camera board
Topic: Raspixxx camera software - changes
Replies: 6
Views: 853

Re: Raspixxx camera software - changes

Pardon my ignorance but how does one get this software? I would like to try it out.
by knute
Wed Dec 12, 2018 2:09 am
Forum: Troubleshooting
Topic: SOLVED:pigpio problem with the latest raspbian
Replies: 0
Views: 139

SOLVED:pigpio problem with the latest raspbian

I installed the latest version of raspian lite and configured it. I then downloaded pigpio and tried to use a simple C program that reads a DHT sensor and got the following error message: 2018-12-11 20:07:12 initMboxBlock: init mbox zaps failed I get the same message if I attempt to start pigpiod. I...
by knute
Mon Dec 03, 2018 10:21 pm
Forum: Java
Topic: Raspbian Stretch Lite - simple Oracle JRE installation
Replies: 5
Views: 6994

Re: Raspbian Stretch Lite - simple Oracle JRE installation

Hello, What is the simplest way to install Java JRE? I don't need JDK. Just install OpenJDK. I just want two things: - I want to receive updates with apt-get upgrade So install OpenJDK. - I want fast JRE - so probably Oracle instead of Open JRE OpenJDK is the same code as Oracle now and it is just ...
by knute
Thu Nov 15, 2018 12:16 am
Forum: Java
Topic: Raspbian that supports javafx
Replies: 1
Views: 3565

Re: Raspbian that supports javafx

You can install openjdk8 and openjfx on the current raspbian and it will work fine.

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