Go to advanced search

by jahboater
Wed Jul 15, 2020 2:13 am
Forum: Other programming languages
Topic: Anyone else using .NET Core 3.1 and ASP.NET Core?
Replies: 5
Views: 140

Re: Anyone else using .NET Core 3.1 and ASP.NET Core?

The introduction of what is undeniably one of the most popular and widely used languages on the planet to the Raspberry Pi - c# - as well as technologies including .NET and ASP.NET "most popular and widely used" on Windows perhaps, but definitely not popular or widely used on Linux, or on UNIX for ...
by jahboater
Tue Jul 14, 2020 2:46 pm
Forum: Beginners
Topic: Cooling of Raspberry PI 4 - 4GB
Replies: 4
Views: 119

Re: Cooling of Raspberry PI 4 - 4GB

Just run it without a heatsink or fan for a few days and see if it throttles (it will come to no harm). You can tell if has throttled by running this command: vcgencmd get_throttled If it says anything other than 0x0, then you could add a heat sink. Hopefully the case allows some ventilation. Make s...
by jahboater
Mon Jul 13, 2020 5:38 pm
Forum: General discussion
Topic: Is there a way to get the hardware and software bit length from the pi its-self?
Replies: 6
Views: 365

Re: Is there a way to get the hardware and software bit length from the pi its-self?

The hardware for recent Pi's supports both 32 and 64 bits. Here "uname" shows the kernel is 64-bits and "file" shows the user land is also 64 bits. Clearly the hardware is running in 64-bit mode. $ uname -a Linux raspberrypi 5.4.50-v8+ #1324 SMP PREEMPT Wed Jul 1 17:13:08 BST 2020 aarch64 GNU/Linux ...
by jahboater
Mon Jul 13, 2020 6:55 am
Forum: Other programming languages
Topic: Anyone using Rust on a PI ?
Replies: 50
Views: 17536

Re: Anyone using Rust on a PI ?

Heater wrote:
Mon Jul 13, 2020 4:45 am
That does not look so elegant anymore.
Much safer!

See ...

https://docs.python.org/3/library/collections.html

Chainmaps might do what you want but they only work for dictionaries as far as I can see.
by jahboater
Mon Jul 13, 2020 3:20 am
Forum: Other programming languages
Topic: Anyone using Rust on a PI ?
Replies: 50
Views: 17536

Re: Anyone using Rust on a PI ?

Nothing happened. How do I get python to pass a slice that can be mutated? Yes that is a problem. Taking a slice as an rvalue always makes copy (creates a new object). see id() >>> v = list(range(10)) >>> v [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] >>> s = v[2:5] >>> s [2, 3, 4] >>> id(v) 548585103872 >>> id(...
by jahboater
Mon Jul 13, 2020 2:04 am
Forum: General discussion
Topic: How do you know if you need to add a cooling component for your Pi4?
Replies: 15
Views: 614

Re: How do you know if you need to add a cooling component for your Pi4?

HawaiianPi wrote:
Mon Jul 13, 2020 1:36 am
Passive heatsinks are yet another option, but it takes a pretty large one to cool well.
I use these from RS rated at 8.2K/W
https://uk.rs-online.com/web/p/heatsinks/7500951/
They are very cheap (£1.57) and provide more than enough cooling to ensure that throttling never happens.
by jahboater
Sun Jul 12, 2020 11:28 pm
Forum: General discussion
Topic: How do you know if you need to add a cooling component for your Pi4?
Replies: 15
Views: 614

Re: How do you know if you need to add a cooling component for your Pi4?

That's nice and cool.

Looks like you will not need this command:

Code: Select all

vcgencmd get_throttled
If it says 0x0 then your Pi is healthy, it has not throttled.
Also it means the power supply is good.
by jahboater
Sun Jul 12, 2020 7:38 pm
Forum: Device Tree
Topic: Cant turn off Power LED on Rasp Pi 4 Model B
Replies: 9
Views: 244

Re: Cant turn off Power LED on Rasp Pi 4 Model B

In case it is of interest, my Pi4 has these entries to turn all the lights off. [pi4] # Disable the PWR LED dtparam=pwr_led_trigger=none dtparam=pwr_led_activelow=off # Disable the Activity LED #dtparam=act_led_trigger=none #dtparam=act_led_activelow=off # Disable ethernet port LEDs dtparam=eth_led0...
by jahboater
Sun Jul 12, 2020 9:04 am
Forum: General discussion
Topic: Which OS is the fastest ?
Replies: 48
Views: 1747

Re: Which OS is the fastest ?

Also known as "throw hardware at the problem." That works right up until you're using the best available hardware, and if it isn't enough, you're back to trying to improve the software. True. But I repeat, its risk free and near zero effort , no code change, for quite a large gain. Learning C and t...
by jahboater
Sun Jul 12, 2020 3:02 am
Forum: Python
Topic: beginner here! where do I start?
Replies: 6
Views: 216

Re: beginer here!

by jahboater
Sat Jul 11, 2020 11:42 pm
Forum: General discussion
Topic: Which OS is the fastest ?
Replies: 48
Views: 1747

Re: Which OS is the fastest ?

This leaves several areas to look at for optimization. First, choice of language processing method. If I am not mistaken, there are ways to actually compile Python programs instead of running everything through an interpreter. Second, rewrite the program in a more efficient language than Python, su...
by jahboater
Sat Jul 11, 2020 12:23 pm
Forum: General discussion
Topic: Which OS is the fastest ?
Replies: 48
Views: 1747

Re: Which OS is the fastest ?

I'm using Raspberry pi 3b+. That's easy then. Get a Pi4. The 3B+ runs at 1.4GHz, the Pi4 has more advanced CPU's (Cortex-A72) that easily run at 2GHz or more. The SD card access is twice as fast, the ethernet is full GIGe, there are two USB3 ports, the memory is many times faster and bigger, video ...
by jahboater
Sat Jul 11, 2020 11:50 am
Forum: General discussion
Topic: Which OS is the fastest ?
Replies: 48
Views: 1747

Re: Which OS is the fastest ?

Hassibayub wrote:
Sat Jul 11, 2020 11:41 am
I look at task manager in raspberry pi I see it only takes a 25% process. I want that somehow it takes complete resources (90-100%) to run my program faster.
You mean the code should be changed so its not waiting on something - a lock ? I/O ?
by jahboater
Sat Jul 11, 2020 9:37 am
Forum: Troubleshooting
Topic: MAKE errors
Replies: 5
Views: 164

Re: MAKE errors

I just actually managed to resolve this. There is a note in the makefile file "# Disable -Werror if there are compile errors ". I removed -Werror and now it compiles and executes fine Yes, you can just tell it to ignore the errors (which shouldn't be there in the first place). It will produce code ...
by jahboater
Fri Jul 10, 2020 11:58 pm
Forum: Other programming languages
Topic: Anyone using Rust on a PI ?
Replies: 50
Views: 17536

Re: Anyone using Rust on a PI ?

I'm not yet convinced anything about Python is elegant. How do I get a slice of an array in Python that I can pass around and through which I can mutate the original array? Not sure if its what you mean, but you can assign to slices (assuming the thing its slicing from is mutable, e.g. not a tuple ...
by jahboater
Fri Jul 10, 2020 7:14 pm
Forum: Beginners
Topic: How to check Rpi4 memory available
Replies: 19
Views: 2109

Re: How to check Rpi4 memory available

I bought an 8GB but at free -m // Mem 3727 free -h // Mem 3.6Gi htop // Mem 3.64G What does this mean? Did I get the wrong one? It should look like this: pi@raspberrypi:~ $ free -m total used free shared buff/cache available Mem: 7866 50 7643 13 172 7696 Swap: 0 0 0 pi@raspberrypi:~ $ free -h total...
by jahboater
Fri Jul 10, 2020 7:11 pm
Forum: Other programming languages
Topic: Anyone using Rust on a PI ?
Replies: 50
Views: 17536

Re: Anyone using Rust on a PI ?

When you take a slice: let window = &sample[i..i + coeff.len()]; presumably Rust must check that the bounds given for the slice are within the bounds of the parent array. So it needs to maintain the bounds throughout. This talk of slicing makes me think how elegant Python is for all this sort of stu...
by jahboater
Fri Jul 10, 2020 6:38 pm
Forum: Other programming languages
Topic: Anyone using Rust on a PI ?
Replies: 50
Views: 17536

Re: Anyone using Rust on a PI ?

Heater wrote:
Fri Jul 10, 2020 6:17 pm
That is cool. Of course it only works if you have not forgotten to put that bounds test in. It's not often I seen people using arrays like that.
It helps maintenance, if someone adds or removes items from the array in the distant future, then the code still works.
by jahboater
Fri Jul 10, 2020 5:12 pm
Forum: Other programming languages
Topic: Anyone using Rust on a PI ?
Replies: 50
Views: 17536

Re: Anyone using Rust on a PI ?

Heater, #include <stdio.h> int main( int argc, const char *argv[] ) { char array[4] = {0}; if( argc < 10 ) return 1; array[argc] = argv[1][0]; printf( "%c\n", array[3]); // just to avoid the entire thing being removed! } Produces this for my build: $ make try gcc -std=gnu18 -funsigned-char try.c -Os...
by jahboater
Fri Jul 10, 2020 2:17 pm
Forum: Other programming languages
Topic: Anyone using Rust on a PI ?
Replies: 50
Views: 17536

Re: Anyone using Rust on a PI ?

All the .len() calls in convolution_fast look like they use a hidden length passed down from the caller with the array (in which case its run-time, and requires extra space) or are known to the compiler (in which case its just like C and is easily checked at compile time). How does Rust know how big...
by jahboater
Fri Jul 10, 2020 12:32 pm
Forum: Other programming languages
Topic: Anyone using Rust on a PI ?
Replies: 50
Views: 17536

Re: Anyone using Rust on a PI ?

Worse still, a release build from clean takes nearly 9 minutes. Rebuilding after an edit takes 20 seconds. Clearly its working properly like make and only compiling the changed, or dependent on the changed, source files. Is there an option to use multiple cores like make -j4 say ? Apparently the Ru...
by jahboater
Thu Jul 09, 2020 12:18 pm
Forum: Beginners
Topic: Newbie Question -- How much CPU load is too much?
Replies: 4
Views: 184

Re: Newbie Question -- How much CPU load is too much?

The Pi4 has four CPU's by the way.
A 50% load on one CPU is really only 1/8 of its capacity.
As noted above, it is a non-issue.

More important is the temperature, which should be kept below 80C to avoid throttling.
by jahboater
Thu Jul 09, 2020 11:25 am
Forum: Off topic discussion
Topic: An observation...NOT a prediction and NOT a "wish list"
Replies: 24
Views: 767

Re: An observation...NOT a prediction and NOT a "wish list"

And how big could a single executable have been in Xenix anyway? In the extreme one just loads one executable to RAM at a time. Like the desktop switchers we had for MS-DOS. It was a full UNIX system with many tasks running as normal. I cant remember the details except that I never liked it (the SC...
by jahboater
Thu Jul 09, 2020 10:16 am
Forum: General discussion
Topic: Which OS is the fastest ?
Replies: 48
Views: 1747

Re: Which OS is the fastest ?

I'm using default pi OS and I think it is slow. What do you mean "slow" - have you some specific examples? What model Pi are you using? The latest model the Pi4 is much faster in all respects (disk, memory, network, CPU, USB etc) than the older versions, and is easily over clocked by 500 MHz or mor...
by jahboater
Thu Jul 09, 2020 8:55 am
Forum: Troubleshooting
Topic: RPi 3B crashes, uses memory up?
Replies: 4
Views: 113

Re: RPi 3B crashes, uses memory up?

Thank you very much! I think I've found the problem which is that every time I removed the power without shutting down clamav would save a file of around 200MB, so I've gone through and deleted these and I now have much more filestore. Is there any reason why you cannot shut the Pi down cleanly? Wi...

Go to advanced search