Go to advanced search

by raspem
Mon Jun 10, 2013 7:57 am
Forum: General discussion
Topic: Is it normal for the RasPi to be this slow?
Replies: 18
Views: 2188

Re: Is it normal for the RasPi to be this slow?

A test I made put the CPU (running on 700MHz) between a Pentium II 450MHz and a Pentium III 800MHz. This was entirely CPU bound with practically no I/O. So the CPU should be a little faster than your result indicates, but at least compiling things means lots of reading and writing from "disk", which...
by raspem
Fri May 03, 2013 4:29 pm
Forum: Other programming languages
Topic: ruby 2 with tk
Replies: 2
Views: 1335

Re: ruby 2 with tk [workaround]

I finally managed to find a way to work around this problem. I hesitate to call is a "solution", since I still don't know exactly why it behaves this way, or why the workaround works... It's clear that there was something fishy going on with the thread scheduling, so I've done lots of testing with t...
by raspem
Wed May 01, 2013 10:00 am
Forum: C/C++
Topic: GTK segmentation error
Replies: 4
Views: 1611

Re: GTK segmentation error

Compile it for debugging (-g) and run it in the debugger (gdb). It should point you to exactly where the problem is.
by raspem
Wed May 01, 2013 7:19 am
Forum: Beginners
Topic: Cannot Execute wget
Replies: 8
Views: 5855

Re: Cannot Execute wget

"Works for me" is not very helpful, but what else can one say? [email protected] ~ $ which wget /usr/bin/wget [email protected] ~ $ ls -l /usr/bin/wget -rwxr-xr-x 1 root root 333280 May 2 2012 /usr/bin/wget [email protected] ~ $ wget http://sheasilverman.com/rpi/raspbian/debs/advancemame-raspberrypi_1-1_armh...
by raspem
Sat Apr 27, 2013 6:43 pm
Forum: C/C++
Topic: GCC problem to compile program with wiringPi.c
Replies: 4
Views: 5827

Re: GCC problem to compile program with wiringPi.c

Btw, Just curious, if i mentioned to include wiringPi.h in the #include, what is this library stuff ? What i learned in the programming is all the functions are defined in the header files ! then y do i need to tell those library files to tell it again :) Compiling your program is actually done in ...
by raspem
Sat Apr 27, 2013 5:30 pm
Forum: C/C++
Topic: GCC problem to compile program with wiringPi.c
Replies: 4
Views: 5827

Re: GCC problem to compile program with wiringPi.c

Gives me error like, tmp/ccv9OGV4.o: In function `main': pi_shutdown.c:(.text+0x3c): undefined reference to `wiringPiSetup' pi_shutdown.c:(.text+0x8c): undefined reference to `pinMode' pi_shutdown.c:(.text+0x90): undefined reference to `digitalRead' collect2: ld returned 1 exit status It's link err...
by raspem
Sat Apr 27, 2013 8:20 am
Forum: C/C++
Topic: build tools
Replies: 1
Views: 627

Re: build tools

Philderbeast wrote:what build tools do people recommend these days, I have seen a lot of projects using cmake, is this something i should look in to, or GNU autotools? or something else all together?
cmake is nice. :) autotools is not. :(
by raspem
Sat Apr 27, 2013 8:17 am
Forum: C/C++
Topic: Compiling problems
Replies: 4
Views: 3261

Re: Compiling problems

Hi! I tried to compile the following code on a raspberry Pi from this website for a project i am currently working on : http://hamsterworks.co.nz/mediawiki/index.php/Watch_Audio But when i try to compile it by using the "gcc -o watch_audio watch_audio.c -Wall -O2" i get the following errors. watch_...
by raspem
Thu Apr 25, 2013 7:19 am
Forum: General discussion
Topic: Display picture, graphs, progress bar and text.
Replies: 6
Views: 1954

Re: Display picture, graphs, progress bar and text.

Hi, I'm new with R.Pi. I want to have a black screen, show small pictures on pre defined places on the screen. I also need to delete the picture form the screen. Show preogress bar (that updates everyh minutes) and texts. Also graphs. Some data are from weather station. Any tip on programming langu...
by raspem
Wed Apr 24, 2013 5:53 pm
Forum: General programming discussion
Topic: rasspbian daemon
Replies: 1
Views: 1911

Re: rasspbian daemon

dzakens wrote:when i compile it with gcc daemon.c -o -Wall daemon i get such errors :
That should be

gcc -Wall daemon.c -o daemon
by raspem
Wed Apr 24, 2013 7:07 am
Forum: General programming discussion
Topic: Do you use a television set as monitor ?
Replies: 4
Views: 3178

Re: Do you use a television set as monitor ?

[My television set does not have hdmi but I would have to use compositie video with RCA connectors. On my PC monitoe I have a free VGA connector. VGA and DVI getting obsolete ? Havn't heard that before. Is it because they don't have sound in the same cable ? Well, if you have nothing else, and don'...
by raspem
Tue Apr 23, 2013 6:47 pm
Forum: General programming discussion
Topic: Do you use a television set as monitor ?
Replies: 4
Views: 3178

Re: Do you use a television set as monitor ?

I used my TV set initially, to get it running, mostly because that was the only hdmi screen I had available at the moment. Works fine, nothing wrong with that. (Except that it occupied my tv set.) For the project it's actually using a tiny 4.2" screen on the RCA connector, but that's not something y...
by raspem
Mon Apr 22, 2013 10:48 am
Forum: Other programming languages
Topic: How to include random questions into a bash script.
Replies: 3
Views: 1173

Re: How to include random questions into a bash script.

There are two problems: - Generate random numbers - Pick a line from something There's no way to do this in bash itself, so you have to rely on other commands and using a file (since it doesn't really have arrays). There are various options. Here are two possibilities (but I'm sure people can come u...
by raspem
Mon Apr 22, 2013 7:15 am
Forum: C/C++
Topic: fgets()
Replies: 2
Views: 908

Re: fgets()

nadir wrote:Here is an example:

Code: Select all

void get_x(int *x)
{	
	char buf[BUFSIZ]; 
	
	printf("enter x value: "); 
	fgets(buf, sizeof(int), stdin); 

That should be sizeof(buf).
by raspem
Sun Apr 21, 2013 5:24 pm
Forum: General programming discussion
Topic: Bash variable scope in Arch Linux
Replies: 7
Views: 1853

Re: Bash variable scope in Arch Linux

Umm... that seems to be the normal behavior. I would be surprised if you have seen anything else. foo=bar sets a local variable in the shell process. It's not an environment variable and will not be inherited by other processes (shells or otherwise). export foo will make it part of the environment, ...
by raspem
Sun Apr 21, 2013 6:15 am
Forum: C/C++
Topic: eclipse
Replies: 8
Views: 2742

Re: eclipse

oshricohen wrote:hi

can i use eclipse to program in c ?
http://www.eclipse.org/downloads/moreinfo/c.php

I've never tried it myself though. (I've only used Eclipse for java).
by raspem
Sun Apr 21, 2013 6:11 am
Forum: Beginners
Topic: Can't SSH/SCP Mac to RPI
Replies: 1
Views: 3255

Re: Can't SSH/SCP Mac to RPI

Can someone help me SSH/SCP files from Mac OS X to Rpi? I can move files from Rpi to Mac, but when I try to go from Mac to Rpi I get this error: “ssh: connect to host 192.168.0.197 port 22: Connection refused” To transfer files from Rpi to Mac, I typed: scp [UserName on Rpi]@[ip address of the rasp...
by raspem
Sun Apr 21, 2013 5:48 am
Forum: General discussion
Topic: How fast (slow) is the Rasperry Pi?
Replies: 37
Views: 5796

Re: How fast (slow) is the Rasperry Pi?

The test that takes the longest time to run took 3.2 seconds (CPU time, running on the normal 700 MHz). This puts it between a Pentium II 450MHz (4.2 s) and a Pentium III 800MHz (2.4 s). raspem, did you run the same test at all the levels of overclocking on the Pi out of interest? No, but I just tr...
by raspem
Sat Apr 20, 2013 5:35 pm
Forum: General discussion
Topic: How fast (slow) is the Rasperry Pi?
Replies: 37
Views: 5796

Re: How fast (slow) is the Rasperry Pi?

I would have assumed that these kinds of threads are soooo passé by now, but apparently some people still haven't received word of, or are unable to comprehend, the original and ongoing intended purpose of the Pi, and that's computing education (primarily at the secondary level for STEM subjects) a...
by raspem
Sat Apr 20, 2013 11:31 am
Forum: General discussion
Topic: How fast (slow) is the Rasperry Pi?
Replies: 37
Views: 5796

Re: How fast (slow) is the Rasperry Pi?

It's perhaps not the ideal platform for video editing or number crunching. That amused me because the other day I was discussing making a proof of concept non-linear video editor on the Pi. With hardware encode/decode of h264 video, its a ideal platform for video editing. On a tangent, it seems PCs...
by raspem
Sat Apr 20, 2013 10:09 am
Forum: General discussion
Topic: How fast (slow) is the Rasperry Pi?
Replies: 37
Views: 5796

Re: How fast (slow) is the Rasperry Pi?

Intersting benckmark. Pretty much confirms the performace evaluation stated in the FAQ with an example. You are not going to rewrite it to use MPI and have it run on a Pi Cluster (Bramble) , are you :razz: ? Well, I'm not sure the algorithm can be parallelized, nor that it would make it faster if i...
by raspem
Sat Apr 20, 2013 9:08 am
Forum: General discussion
Topic: How fast (slow) is the Rasperry Pi?
Replies: 37
Views: 5796

How fast (slow) is the Rasperry Pi?

A very long time ago (almost 25 years :shock:), I wrote a little program in C. Exactly what it does isn't important, but it can take some time to run on some input, and I have run the same test suite on almost every computer that I've owned or worked with since then, and kept records of the running ...
by raspem
Thu Apr 18, 2013 1:53 pm
Forum: Beginners
Topic: What have the permissions been set to +w for groups and all?
Replies: 5
Views: 929

Re: What have the permissions been set to +w for groups and

This is weird, but apparently documented an by design. It's using the umask in this case. From the man page: If none of these [ugoa] are given, the effect is as if a were given, but bits that are set in the umask are not affected. This makes a little sense when using "+", but is a bit strange with "...
by raspem
Wed Apr 17, 2013 5:35 pm
Forum: Other programming languages
Topic: ruby 2 with tk
Replies: 2
Views: 1335

Re: ruby 2 with tk

So, I decided to check what's going on when irb is apparently hanging during the "require 'tk'", so I attached an strace to the process... and then it works! :shock: It doesn't hang anymore.

Something really strange going on here, with threads, scheduling, or something, I dunno... :?
by raspem
Wed Apr 17, 2013 7:56 am
Forum: General programming discussion
Topic: Which Language to Learn?
Replies: 53
Views: 14867

Re: Which Language to Learn?

There's no one language which will solve all problems (contrary to what some people think, esp. in middle management ;) ) But if it's for fun, and performance is not an issue: ruby. It's beautiful (well, for a script-style language anyway), it's powerful, it's FUN. I've programmed for 30 years in mo...

Go to advanced search