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by PeterO
Mon Oct 22, 2018 2:15 pm
Forum: Troubleshooting
Topic: Lightning bolt with 5.5 4A power supply
Replies: 10
Views: 264

Re: Lightning bolt with 5.5 4A power supply

To add to what has already been said... In my experience, just about any old power supply will do. In fact, the constant "advice" given on this forum to always buy the "official" power supply seems misguided. The fact is that you really only need all those amps if you are running lots of peripheral...
by PeterO
Sun Oct 21, 2018 5:08 pm
Forum: Media centres
Topic: New TV Tuner from HQ
Replies: 65
Views: 1609

Re: New TV Tuner from HQ

This new dongle comes with an extendable antenna (120-350mm) with a 1 metre cable and MCX connector that plugs into the side of the USB dongle. The antenna works best when its length is a multiple of a quarter of the ADS-B transmission wavelength, which is 69mm. Experiment with different antenna le...
by PeterO
Sun Oct 21, 2018 4:19 pm
Forum: Media centres
Topic: New TV Tuner from HQ
Replies: 65
Views: 1609

Re: New TV Tuner from HQ

68mm is λ/4 at 1.09 Ghz.

PeterO
by PeterO
Fri Oct 19, 2018 3:33 pm
Forum: C/C++
Topic: Double Check - Free`ing the right thing
Replies: 13
Views: 226

Re: Double Check - Free`ing the right thing

If you need triple indirection then IMHO you are almost certainly doing it wrong ! PeterO Yes yes! Exactly my thoughts. Its never needed and probably quite hard to debug if it doesn't work :( So....... for my benefit of learning ... in general... how do you pass a pointer to pointer array in the fo...
by PeterO
Fri Oct 19, 2018 2:14 pm
Forum: C/C++
Topic: Double Check - Free`ing the right thing
Replies: 13
Views: 226

Re: Double Check - Free`ing the right thing

void image_free_pixel_data(uint32_t ***pixel_data, int *height)
If you need triple indirection then IMHO you are almost certainly doing it wrong !

PeterO
by PeterO
Tue Oct 09, 2018 7:07 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Serial connection: No such file or directory: ' /dev/ttyS0'
Replies: 3
Views: 124

Re: Serial connection: No such file or directory: ' /dev/ttyS0'

It looks like you have a USB serial adapter plugged in ...

Code: Select all

[    6.207354] usb 1-1.2: cp210x converter now attached to ttyUSB0
If that is the device you are trying to use, then it is accessed via /dev/ttyUSB0

Also, the onboard serial interface is accessed via /dev/ttyAMA0

HTH

PeterO
by PeterO
Mon Oct 01, 2018 9:46 am
Forum: Off topic discussion
Topic: Windows 10 ARM64 on R-Pi 3
Replies: 11
Views: 1026

Re: Windows 10 ARM64 on R-Pi 3

Castle_Romeo wrote:
Mon Oct 01, 2018 9:31 am
If I were to find a Raspberry Pi clone that has a Qualcomm chip, would it work???
You would have to ask that question on the support forum for what ever board you choose to find, because a board with a Qualcomm chip is by definition NOT a Raspberry Pi.

PeterO
by PeterO
Thu Sep 27, 2018 9:26 pm
Forum: Networking and servers
Topic: what is the best OS for NFS
Replies: 19
Views: 590

Re: what is the best OS for NFS

I ma expecting the folders that are in 192.168.0.15 /mnt/nfs/ to show up in 192.168.0.21 /export/secam. I got nothing. Well there's your problem then :shock: You seem to have got the definition of server and client the wrong way round. sudo mount 192.168.0.21:/export/secam /mnt/nfs/ That command wi...
by PeterO
Thu Sep 27, 2018 9:02 pm
Forum: Networking and servers
Topic: what is the best OS for NFS
Replies: 19
Views: 590

Re: what is the best OS for NFS

Looks like it has worked. What output were you expecting it to produce ?
Why do you think it has failed ?

PeterO
by PeterO
Fri Sep 21, 2018 1:04 pm
Forum: Official Foundation Display
Topic: GTK3 Comboboxes unusable on touch display
Replies: 4
Views: 258

Re: GTK3 Comboboxes unusable on touch display

Worked around problem using a GtkMenuButton and a GtkPopover, which works nicely :-)
Image
PeterO
by PeterO
Thu Sep 20, 2018 11:53 am
Forum: Official Foundation Display
Topic: GTK3 Comboboxes unusable on touch display
Replies: 4
Views: 258

Re: GTK3 Comboboxes unusable on touch display

Combobox is unusable. Install the demo and try it yourself. The "Items with icons" example won't allow the selection to be changed from "Warning" With a mouse the selection highlighting follows the mouse pointer, but with the touch screen the selection won't change. And it is inconsistent too. Once ...
by PeterO
Thu Sep 20, 2018 10:26 am
Forum: Official Foundation Display
Topic: GTK3 Comboboxes unusable on touch display
Replies: 4
Views: 258

GTK3 Comboboxes unusable on touch display

I've discovered that the combobox in GTK3 is unusable on a touch screen like the official 7" display. First found the problem in my own code then found the combobox demo code in gtk3-demo has the same problems. gtk3-demo comes from the gtk-3-examples package and can can be install with sudo apt-get ...
by PeterO
Mon Sep 17, 2018 3:26 pm
Forum: Troubleshooting
Topic: Running into problems with serial over USB
Replies: 8
Views: 256

Re: Running into problems with serial over USB

"...put the tty into raw mode"... Not sure what you mean by this. I have a serial device which I am accessing using libserialport. There are two functions sp_read and sp_write which allow me to send and receive data over the chosen port. what would putting the tty into raw mode do for me? I have no...
by PeterO
Mon Sep 17, 2018 7:03 am
Forum: Troubleshooting
Topic: Running into problems with serial over USB
Replies: 8
Views: 256

Re: Running into problems with serial over USB

First thought, have you put the tty into raw mode ?

PeterO
by PeterO
Sat Sep 15, 2018 10:20 am
Forum: Graphics programming
Topic: gcc error: main.c No such file or directory
Replies: 4
Views: 311

Re: gcc error: main.c No such file or directory

gcc is telling you there is no file called main.c in the current working directory.

In which subdirectory have you put the main.c file ?

Oh and why do you think you need to use sudo ?

PeterO
by PeterO
Fri Sep 14, 2018 4:45 pm
Forum: Off topic discussion
Topic: What was your first computer?
Replies: 375
Views: 91410

Re: What was your first computer?

What's more telling is that, before I even got my first home computer, I trained on an IBM 1966 mainframe, learning true machine code (even some binary programming) and went on to cut my teeth using COBOL on an IBM 2966 at British Aerospace. If I'd been smart (and not employed otherwise) in 1999, I...
by PeterO
Sun Sep 09, 2018 9:19 am
Forum: Other programming languages
Topic: Bash script for read .txt
Replies: 11
Views: 466

Re: Bash script for read .txt

Try

Code: Select all

echo -n "Hello World" > led.txt
The "-n" will remove the new line character from the end of the string.

PeterO
by PeterO
Sun Sep 09, 2018 6:41 am
Forum: C/C++
Topic: Getting nonsense from GCC floats (doubles too)
Replies: 9
Views: 508

Re: Getting nonsense from GCC floats (doubles too)

My advice, never test anything to do with FFTs with "live" data. Always force a simple waveform in at the earliest possible stage so that your code is working with a known signal and a known spectrum. Trying to debug numerical problems with random data is a nightmare !

PeterO
by PeterO
Sat Sep 08, 2018 8:19 pm
Forum: Troubleshooting
Topic: Seagate hdd problem.
Replies: 13
Views: 364

Re: Seagate hdd problem.

For some reason, if I have a USB booting Raspbian, after the boot process has finished and the GUI loads etc, when I plug in the expansion drive, the system stops working. I think that the HDD somehow unmounted the USB boot drive. I expect the initial current taken by the HDD is more than the PI PS...
by PeterO
Sat Sep 08, 2018 7:31 pm
Forum: Troubleshooting
Topic: Seagate hdd problem.
Replies: 13
Views: 364

Re: Seagate hdd problem.

For some reason, if I have a USB booting Raspbian, after the boot process has finished and the GUI loads etc, when I plug in the expansion drive, the system stops working. I think that the HDD somehow unmounted the USB boot drive. I expect the initial current taken by the HDD is more than the PI PS...
by PeterO
Fri Sep 07, 2018 9:27 am
Forum: General discussion
Topic: Glade control panel
Replies: 5
Views: 182

Re: Glade control panel

picandies wrote:
Fri Sep 07, 2018 9:18 am
Has anyone on the rpi forum used Glade to make a hardware control app?
Yes. But I can't find the code at the moment :oops:

Image

PeterO
by PeterO
Thu Sep 06, 2018 9:36 am
Forum: General discussion
Topic: Glade control panel
Replies: 5
Views: 182

Re: Glade control panel

Using Python with Gtk3 is covered here : https://python-gtk-3-tutorial.readthedocs.io/en/latest/
Specifics on using Glade are here : https://python-gtk-3-tutorial.readthedo ... ilder.html

HTH

PeterO
by PeterO
Tue Aug 28, 2018 4:23 pm
Forum: Other
Topic: Download PROTA OS, new headless-oriented OS for B+ for free
Replies: 30
Views: 8864

Re: Download PROTA OS, new headless-oriented OS for B+ for free

This thread is 3 years old, and product seems to have been dead for just as long.
PeterO
by PeterO
Tue Aug 28, 2018 6:51 am
Forum: Troubleshooting
Topic: RPi3 won't mount external USB drive
Replies: 26
Views: 814

Re: RPi3 won't mount external USB drive

I run similar (*) Seagate drives on PI2s and Pi3s. On a Pi2 with a 4A supply it is plugged directly into the PI's USB port On a Pi3B+ with a 2.5A supply I use the (no longer available) Pimoroni raspberry shaped four port powered hub. Not had any problems with either configuration. PeterO (*) Its har...
by PeterO
Fri Aug 24, 2018 11:33 am
Forum: Advanced users
Topic: Can't manually enable experimental OpenGL driver on "clean" installation
Replies: 6
Views: 314

Re: Can't manually enable experimental OpenGL driver on "clean" installation

Found this old comment by Simon Long... https://www.raspberrypi.org/blog/another-new-raspbian-release/#comment-1252967 Perhaps the reason why the driver is not activated depends on one of these factors... Maybe , but that is over 2 years ago and many things have changed in that time...... I don't k...

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