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by rpdom
Sun Aug 04, 2019 4:23 am
Forum: Beginners
Topic: What is the shiny part on RPI4 (above the raspberry) for?
Replies: 6
Views: 306

Re: What is the shiny part on RPI4 (above the raspberry) for?

It's the WiFi and Bluetooth chip under a metal shield.
by rpdom
Sat Aug 03, 2019 7:43 pm
Forum: Beginners
Topic: Raspberry Pi 4 4GB and video streaming
Replies: 21
Views: 1163

Re: Raspberry Pi 4 4GB and video streaming

This is a forum dedicated to the Raspberry Pi. It is unlikely anyone will recommend another SBC on here.
by rpdom
Sat Aug 03, 2019 7:32 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39551

Re: Project Digital Apocalypse Not Now

There's about 50 lines of noise (including a large chunk of the DATA DIVISION) that moves from program to program with any COBOL I write. I've worked with a professional COBOL programmer in the past year (getting V6.2 running), I learned more from him in a week than I'd learned hacking ugly COBOL f...
by rpdom
Sat Aug 03, 2019 7:24 pm
Forum: Troubleshooting
Topic: Cannot login through GUI
Replies: 10
Views: 177

Re: Cannot login through GUI

If you've been running sudo apt-get upgrade (or dist-upgrade) at all, you should run sudo apt-get clean every now and then to delete the old installation files that are no longer needed.

If you only use sudo apt upgrade (or full-upgrade) you don't need to do that.
by rpdom
Sat Aug 03, 2019 7:14 pm
Forum: C/C++
Topic: compile Linux C programs to use cpu cores exclusively
Replies: 26
Views: 1111

Re: compile Linux C programs to use cpu cores exclusively

Heater wrote:
Sat Aug 03, 2019 6:34 pm
rpdom,

Well spotted. I fixed. Typical programmer, off by one errors all over the place :)
No worries. I've spent years of switching between languages that start arrays at 0 and some that start at 1.
by rpdom
Sat Aug 03, 2019 5:00 pm
Forum: C/C++
Topic: compile Linux C programs to use cpu cores exclusively
Replies: 26
Views: 1111

Re: compile Linux C programs to use cpu cores exclusively

So "0x01 is the hexadecimal representation of the bits 00000001. Notice that the bit zero is set to 1, being the first bit that means run on core 0. If you want to run on core 2 use: $ taskset 0x02 myProgram Where "0x02" is 00000010 in binary, the second bit is set, so core 2. If the cores start at...
by rpdom
Sat Aug 03, 2019 4:58 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 807
Views: 76461

Re: Raspberry Pi 4 Thread - general discussion

It's true: the latest Pi4 isn't quite as cheap as it is being made out. As mentioned above, the board £55, Power £8, fan £10, MicroHDMI 2 X £5, SD card £8. Definitely pushing close to £100. Don't forget the 2x4K monitors, network cable (if not using wifi), case, keyboard, mouse, assorted USB device...
by rpdom
Sat Aug 03, 2019 1:54 am
Forum: Networking and servers
Topic: Default Password No Longer Working When Connecting Via SSH
Replies: 3
Views: 145

Re: Default Password No Longer Working When Connecting Via SSH

If you have allowed SSH access from the internet and have not changed the default password you should switch that Pi off immediately, remove the card and write a fresh copy of Raspbian Buster to it. Then change the password before allowing port forwarding. Your Pi has been taken over by someone else...
by rpdom
Sat Aug 03, 2019 1:44 am
Forum: Troubleshooting
Topic: Raspberry Pi GPIO pins automatically on high
Replies: 5
Views: 199

Re: Raspberry Pi GPIO pins automatically on high

Have you got a volt meter you could test the voltage between the 3.3V and 5V pins and grounds? I'm nut sure, but I think you might have the cable connected to the Pi the wrong way round. Checking the supply pins will confirm that. If you haven't got a meter, head off to ebay and buy one of the cheap...
by rpdom
Fri Aug 02, 2019 8:21 pm
Forum: Raspbian
Topic: RaspberryPI Zero/W headless images
Replies: 8
Views: 310

Re: RaspberryPI Zero/W headless images

Write a Raspbian Lite image to the card. Create a ssh.txt file on the card. Create a wpa_supplicant.conf file on the card with the WiFi credentials. Eject card from PC. Put card in Pi Zero. Power up Pi. Wait a few minutes for first boot to complete. SSH connect to Pi. That's what I do. No keyboard. ...
by rpdom
Fri Aug 02, 2019 6:51 pm
Forum: General discussion
Topic: 4gb - 4B Demand must be high.
Replies: 134
Views: 5929

Re: 4gb - 4B Demand must be high.

I'm not allowed to drink Grapefruit juice, which is a pity because I really like it.
by rpdom
Fri Aug 02, 2019 6:28 pm
Forum: Troubleshooting
Topic: sending a value from php to python script
Replies: 2
Views: 60

Re: sending a value from php to python script

Code: Select all

	exec("sudo python /var/www/html/scripts/Weichen2.py" . $id .);
Shouldn't there be a space after the ".py". Otherwise it could be an issue with the web server not being allowed to use sudo (a good thing usually.) Does the Python really need sudo access?
by rpdom
Fri Aug 02, 2019 6:07 pm
Forum: Raspbian
Topic: Need Raspbian 9
Replies: 4
Views: 231

Re: Need Raspbian 9

Most of the older releases are available in the download archives https://downloads.raspberrypi.org/raspbian/images/
by rpdom
Fri Aug 02, 2019 2:15 pm
Forum: Beginners
Topic: Coding languages on the Pi?
Replies: 26
Views: 698

Re: Coding languages on the Pi?

Programming languages meant for DOS programs. Like Pascal etc... As I said earlier, almost every language you can think of is available in Raspbian. A lot of them will just need installing. One example: pi@raspberrypi:~ $ apt show fpc Package: fpc Version: 3.0.4+dfsg-22+rpi1 Priority: optional Sect...
by rpdom
Fri Aug 02, 2019 2:07 pm
Forum: Troubleshooting
Topic: what is metric 202 in ip route raspberry pi 4
Replies: 5
Views: 97

Re: what is metric 202 in ip route raspberry pi 4

Metric is a measure of priority. Routes with a lower "metric" are preferred to ones with a higher metric. For example you may have a 1Gb wired connection with a metric of 100 and a wireless connection with 200. The 100 connection will be the preferred route.
by rpdom
Fri Aug 02, 2019 1:24 pm
Forum: Beginners
Topic: Why does the raspberry-pi-zero return “Illegal instruction” after I wrote a command that is working on raspberry-pi 3 B+
Replies: 9
Views: 252

Re: Why does the raspberry-pi-zero return “Illegal instruction” after I wrote a command that is working on raspberry-pi

The OP is running a Python 3 program so I would guess any Illegal Instruction is through some C extension being used, which was provided, rather than they built themselves. I wouldn't know where to start with trying to figure out which C Extension that might be, where it would be called in the hier...
by rpdom
Fri Aug 02, 2019 11:38 am
Forum: Beginners
Topic: Coding languages on the Pi?
Replies: 26
Views: 698

Re: Coding languages on the Pi?

ProDigit wrote:
Fri Aug 02, 2019 11:28 am
I would presume this would include most DOS based programming languages?
Such as?

Specific vendor versions of languages may not be available.

Generic versions may be.

Don't expect to run .bat scripts or powershell. The bash shell is quite a bit more flexible, but uses different commands.
by rpdom
Fri Aug 02, 2019 11:36 am
Forum: Troubleshooting
Topic: Monitor HELP
Replies: 6
Views: 201

Re: Monitor HELP

I am using a rpi 3 B+ running NOOBS with an LG monitor. The question the aBUGSworstnightmare asked is still valid. NOOBS is not an Operating System. It is an OS installer and boot selector. Are you running Raspbian (installed from NOOBS) or something else? Is it the current Buster release or an old...
by rpdom
Fri Aug 02, 2019 11:31 am
Forum: General discussion
Topic: Meaningless boot problem
Replies: 15
Views: 452

Re: Meaningless boot problem

- I still can't understand why sd card corrupts in these cases, somehow sd card should be protected. Really? So how should the card be protected? The Raspberry Pi is no different than any other Linux, Windows or Mac OS PC. You need to shut down the operating system. If you just cut the power you ri...
by rpdom
Fri Aug 02, 2019 10:49 am
Forum: Beginners
Topic: Coding languages on the Pi?
Replies: 26
Views: 698

Re: Coding languages on the Pi?

We've had plenty of threads on the benefits of various languages, and they always end up in a language war. I've no idea what you're referring to James, but sticking to the script, basically almost any programming language ever written is available for the Pi. Just check the add/remove software men...
by rpdom
Fri Aug 02, 2019 10:27 am
Forum: General discussion
Topic: 4gb - 4B Demand must be high.
Replies: 134
Views: 5929

Re: 4gb - 4B Demand must be high.

People on a tight budget will go for the lowest cost option.

People on a not so tight budget will go for the best option they can afford.

Hardly anyone will go for the mid-range option unless it is the only one available to them.

This much I do know about marketing.
by rpdom
Fri Aug 02, 2019 7:52 am
Forum: Beginners
Topic: Coding languages on the Pi?
Replies: 26
Views: 698

Re: Coding languages on the Pi?

Most of those are either installed or can be installed easily. Perl is already installed. PHP is easy to install. C# is a microsoft thing, but I believe Mono supports it. Shell? Which one? Bash is the standard one. SQL? Again, which one? MariaDB (was MySQL) is easy to install. Support for various ot...
by rpdom
Fri Aug 02, 2019 6:46 am
Forum: HATs and other add-ons
Topic: What are people using for SATA interfaces?
Replies: 2
Views: 156

Re: What are people using for SATA interfaces?

USB3 is the only way you'll get a decent speed from a SATA interface. I don't believe there are any HATs that will provide one. Possibly it could be done via SPI, but it would a custom interface and custom kernel drivers and still wouldn't be as fast. I just use external USB 2.5" drives (SSD and HDD...
by rpdom
Fri Aug 02, 2019 6:39 am
Forum: Beginners
Topic: IP Addresses and Pi Connection to My Network
Replies: 6
Views: 216

Re: IP Addresses and Pi Connection to My Network

192.168.1.1xx 192.168.1.1yy Where yy is 12 counts higher then xx. (I guess I'm not supposed to reveal the actual numbers). It's harmless to show any numbers that start with 192.168 or 10 or 172.16 to 172.31. Those are all private local addresses and can't be accessed by anyone outside of your local...

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