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by jahboater
Tue May 26, 2020 11:33 pm
Forum: General discussion
Topic: Does dust kill the Rasberry Pi 4?
Replies: 11
Views: 435

Re: Does dust kill the Rasberry Pi 4?

It might attract less dust if placed on edge - which also improves the convection cooling.
by jahboater
Mon May 25, 2020 11:11 pm
Forum: General programming discussion
Topic: aarch64 vs. armhf + Linux + GCC
Replies: 5
Views: 267

Re: aarch64 vs. armhf + Linux + GCC

Not quite, whilst the scalar FPU in Aarch32 is capable of double precision floats, the SIMD NEON is only capable of single precision (Aarch32 behaves as armv7 which never had double precision in NEON, its registers are only 64 bit so can't hold multiple doubles). You only get double precision float...
by jahboater
Mon May 25, 2020 7:38 pm
Forum: General programming discussion
Topic: aarch64 vs. armhf + Linux + GCC
Replies: 5
Views: 267

Re: aarch64 vs. armhf + Linux + GCC

Specifically I wanted to use double precision FP NEON instructions as well as integer 64bit arithmetics. You do not need to run a 64-bit OS for this. Standard Raspbian will do that just fine! 1) NEON works perfectly in 32-bit mode. All Pi's from day one, even the Pi Zero have double-precision float...
by jahboater
Mon May 25, 2020 12:20 pm
Forum: Beginners
Topic: Starting out with Raspberry Pi questions
Replies: 5
Views: 229

Re: Starting out with Raspberry Pi questions

what exactly can I do with it? That's like saying "I have just purchased a car, where can I go in it?" Whats different about the Pi is that it is tiny and cheap, easy to setup, and almost impossible to damage with software. That is , you may learn and experiment as much as you like, and the worst t...
by jahboater
Sun May 24, 2020 11:40 pm
Forum: General discussion
Topic: Where to buy micro SD cards
Replies: 6
Views: 201

Re: Where to buy micro SD cards

I use Amazon for these Sandisk A1 class cards - which work very well in the Pi.
https://www.amazon.co.uk/SanDisk-microS ... 558&sr=8-2
Never had a fake one.
by jahboater
Sun May 24, 2020 11:38 pm
Forum: Troubleshooting
Topic: File too large error, possibly conflict in formatting
Replies: 6
Views: 142

Re: File too large error, possibly conflict in formatting

Is this NOOB's or a simple Rasbian image?

Raspbian itself has two partitions, a tiny FAT32 partition called boot and the remainder of the disk which is ext4.

The ext4 filesystem can handle any sized file (up to 16 TiB!!) but the FAT32 partition has very little free space.
by jahboater
Sun May 24, 2020 9:42 am
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

My just "run" thing is just an example, there is also just "build", just "reformat", just "lint" etc, etc. Not to mention that the just "run" thing also goes out and fetches all required package dependencies, recompiles everything as needed, builds the executable and runs it. That's impressive if i...
by jahboater
Sun May 24, 2020 8:38 am
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

You can't just write some code and say "run". Why on Earth not? You can of course, but few people bother, its not very useful for a large project. Its the sort of thing beginners writing hello world programs like. $ cc hello.c && a.out Hello world! The little TCC compiler did it directly. alias hel...
by jahboater
Sun May 24, 2020 1:15 am
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

Still using tools and techniques from half a century ago. If you are talking about .a files and ar, and .so files, they are nothing to do with C/C++. (In fact .a files are not even specific to program libraries, you may store anything in them, and .so files and lazy linking are not so old anyway). ...
by jahboater
Sat May 23, 2020 11:23 pm
Forum: Other programming languages
Topic: Linux shell script to control pi motor hat
Replies: 5
Views: 440

Re: Linux shell script to control pi motor hat

darkskyseeker wrote:
Fri May 22, 2020 5:38 pm
Just a little resistance to getting sidetracked with another learning curve. But then again, why stop learning?
The Raspberry Pi is all about learning, that is its raison d'être.

Love it!
by jahboater
Sat May 23, 2020 10:43 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

Then there are two types of library, "static" libraries and "dynamic" or "shared". When using static libraries it's compiled code is actually added to the code produced when compiling your program. Every program your build will end up with a copy of the library code within it. On the other hand dyn...
by jahboater
Sat May 23, 2020 10:21 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

But where am I supposed to store the common libraries, since i have to manage them manually and would like to have a separate folder for different projects? Please don't keep using the word "manage" them because its much simpler than that. You may store libraries wherever you like. They could be in...
by jahboater
Sat May 23, 2020 8:00 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

On the Arduino-ESP I can write quite elaborate stuff and be really productive*, but I love just to push "Verify/Compile" and Upload instead of having to break my head to generate make-files and manage dependencies. A good complier should do that automatically and better than me. A compiler wont do ...
by jahboater
Sat May 23, 2020 6:17 pm
Forum: General discussion
Topic: SSD vs SD
Replies: 11
Views: 604

Re: SSD vs SD

Heater wrote:
Sat May 23, 2020 2:10 pm
Doesn't stuff in a tempfs vaporize on a power down?
Correct.
I suggested it for temporary files.

/tmp is tmpfs by default on most systems nowadays.

My first UNIX (UTS on an Amdahl mainframe) had /tmp in memory nearly 40 years ago!
by jahboater
Sat May 23, 2020 6:15 pm
Forum: General discussion
Topic: SSD vs SD
Replies: 11
Views: 604

Re: SSD vs SD

OP probably isn't using a 4B. They don't specify but do state they've been seeing this problem for 2 years. I.e. before the launch of the 4B. Yes, good point. (added in an edit)The default limit for tmpfs os 50% of RAM, you're actually allowing tmpf to use more than the default. Correct. I have bee...
by jahboater
Sat May 23, 2020 4:50 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

This part is not so clear to me. I have never seen a real Unix. Except maybe for the brief time I developed code on a Sun 360 work station. Did Unix even have a package manager? I assumed people shared code on tape or via FTP and some how had to build it from tar balls and the like. Yes. I don't re...
by jahboater
Sat May 23, 2020 3:40 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

Heater, I guess that had C/C++ always had a package system like npm, pip, crates etc then most of what is in the Debian repos would not need to be there. It would not need to be duplicated into RedHat's RPM, Canonical's repos and so on an so on... There is the history of C being the OS implementatio...
by jahboater
Sat May 23, 2020 3:33 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

Heater, Yes, makes sense. I have often thought that systems like Debian should not even include all those dev packages and many others besides. The operating system package system should only be concerned with what is needed to build a stable operating system More confusingly I see that the Debian r...
by jahboater
Sat May 23, 2020 2:14 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

If you are lucky and what you want to use is packaged in Raspbian. Often not the case. True, but are you saying these other repositories contain everything? It seems like a 1) a duplication of effort and 2) an added complication for the developer. I suppose pip and the like were built to cater for ...
by jahboater
Sat May 23, 2020 2:03 pm
Forum: General discussion
Topic: SSD vs SD
Replies: 11
Views: 604

Re: SSD vs SD

tmpfs is all well and good but you run the risk of making the system swap sooner and more often. With the default swap file on the SD card that may negate the gains of tmpfs. I set an upper limit on the tmpfs size: tmpfs /tmp tmpfs defaults,noatime,size=3g 0 0 On my 4GB Pi4, this allows up to 3GB o...
by jahboater
Sat May 23, 2020 1:59 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

All these language ecosystems have centralized maintained library package system. npm, pip, crates, respectively. Makes life so much easier than messing with the chaos of the C/C++ world. Isn't it just "sudo apt install libxxx" for C/C++? Sometimes you may need "sudo apt install libxxx-dev" to get ...
by jahboater
Sat May 23, 2020 1:39 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

Sorry but I have got no clue of what you mean: adding -lpigpio to what? The compiler command line. You can set that up in any IDE or simply append it to the command line: cc example.c -o example -lpigpio compiles the program in "example.c" and places the executable in the file called "example". The...
by jahboater
Sat May 23, 2020 1:37 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

But for general I2C access then just adding -lpigpio should be enough. Sorry but I have got no clue of what you mean: adding -lpigpio to what? The compiler command line. You can set that up in any IDE or simply append it to the command line: cc example.c -o example -lpigpio compiles the program in ...
by jahboater
Sat May 23, 2020 1:03 pm
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

That problem is what I was talking about. In the C/C++ world there is no such convenient way of finding or using nicely prepackaged libraries as you find for Arduino. It's a mess, you have to somehow find some library written my someone, somewhere, download the source from wherever they keep it, ad...
by jahboater
Sat May 23, 2020 11:55 am
Forum: C/C++
Topic: Tutorial to start programming in c++ for Arduino transfugees.
Replies: 72
Views: 1681

Re: Tutorial to start programming in c++ for Arduino transfugees.

For GPIO access, use:

http://abyz.me.uk/rpi/pigpio/cif.html

which is included with Raspbian

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