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by Heater
Mon Jun 10, 2013 1:54 pm
Forum: General discussion
Topic: please help
Replies: 40
Views: 11987

Re: please help

ahmedwahdan, I am assuming the following: 1) In the end you will have your sensors connected to a Pi via serial port. Or perhaps even the GPIO/I2C/SPI on the GPIO header. 2) The Pi will be your server. That is for web pages and other connections from your mobile phone (or other) apps. 3) You are usi...
by Heater
Mon Jun 10, 2013 12:27 pm
Forum: General discussion
Topic: How much can I overclock?
Replies: 9
Views: 3933

Re: How much can I overclock?

miker00lz, I've got my raspi running at 1.0 GHz CPU, 500 MHz SDRAM clock, overvolt is set to 6. I'm using force_turbo as well. It's totally stable, I have QEMU running on it right now. Windows Server 2003 guest OS installed, and it's been running perfectly with a full-time 100% CPU load for 2 days. ...
by Heater
Mon Jun 10, 2013 10:54 am
Forum: General discussion
Topic: Is it normal for the RasPi to be this slow?
Replies: 18
Views: 2629

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

I installed qemu on my quadcore Intel PC and used to to run Raspian which was then used to compile a rather large project. Turned out to take about the same time as on the Pi itself. About 12 hours in this case.
by Heater
Mon Jun 10, 2013 9:30 am
Forum: General discussion
Topic: Adding RAM to Pi
Replies: 52
Views: 101291

Re: Adding RAM to Pi

stevech, object oriented programming leads to code size bloat. No it does not. Or at least it need not. This is a common myth. If you need multiple instances of something, for example a buffer, you can write that in C using pointers to your select which of your various buffers you are working on. Yo...
by Heater
Mon Jun 10, 2013 8:54 am
Forum: General discussion
Topic: Is it normal for the RasPi to be this slow?
Replies: 18
Views: 2629

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

Is it normal for a full up Linux running computer costing 48 Euro (A rather high off the shelf price in my local store), consuming only 1 Watt and being the size of a credit card to be able to calculate a million digits of Pi in 17 seconds?

That's a first in my experience.
by Heater
Mon Jun 10, 2013 8:10 am
Forum: General discussion
Topic: What else can I do with a pi?
Replies: 8
Views: 1439

Re: What else can I do with a pi?

In what way is Raspian "laggy". It performs as well as I expect for a 700Mhz machine using SD card storage. I only ever use it from the command line via ssh though.
by Heater
Mon Jun 10, 2013 8:03 am
Forum: General discussion
Topic: Industrial Embedded
Replies: 25
Views: 6223

Re: Industrial Embedded

Speed is not everything. For most of what I do with a Pi or other ARM boards they are all plenty fast enough. I bet this is true for most apps of most users. At that point the price, the design stability and the community become far more valuable than raw speed. The 200 Euro ARM board I mentioned do...
by Heater
Sun Jun 09, 2013 6:48 pm
Forum: General discussion
Topic: Few questions before purchase..
Replies: 10
Views: 1801

Re: Few questions before purchase..

Jim, If you look at an old tube flip-flop as used in you basic memory or counter circuit you find it is made of two triodes. Linking such tube flip-flops together in counter or other circuits required capacitor coupling. I think it's impossible to build a flip-flop with only two active components wi...
by Heater
Sun Jun 09, 2013 6:02 pm
Forum: General discussion
Topic: please help
Replies: 40
Views: 11987

Re: please help

ahmedwahdan, To get you started with node.js client/server programming here is an example I created for myself a little while ago as I was getting into how to make TLS work. The point here is actually the script that generates all the SSL certificates and keys. I had a devil of a job getting that ri...
by Heater
Sun Jun 09, 2013 5:18 pm
Forum: General discussion
Topic: Xbox 360 games on Raspberry Pi
Replies: 12
Views: 14346

Re: Xbox 360 games on Raspberry Pi

caljustcal ...because apparently you can! Where on earth did you get that idea from? I would suggest that if you have a Raspberry Pi you already have a enough of a game learning the ins and outs of the Pi and Linux and programming and making your own games. It's infinitley more fascinating and rende...
by Heater
Sun Jun 09, 2013 5:07 pm
Forum: General discussion
Topic: please help
Replies: 40
Views: 11987

Re: please help

OtherCrashOverride, ...webserver, JavaScript, XML/JSON, SSL, AJAX seem like a Rube Goldberg machine...to me. You know what? I agree. The whole web stack looks like something Heath Robinson would have devised http://en.wikipedia.org/wiki/W._Heath_Robinson . (Being British I have to mention we got the...
by Heater
Sun Jun 09, 2013 3:50 pm
Forum: General discussion
Topic: please help
Replies: 40
Views: 11987

Re: please help

OtherCrashOverride, Seems like a bit overkill. You can talk to GPIO, serial port, and network sockets without ever leaving the language he already knows: C Yes, you can do serial port. GPIO, and network sockets in C. I have done so myself a few times in the past. Of course you can do pretty much any...
by Heater
Sun Jun 09, 2013 1:41 pm
Forum: General discussion
Topic: Can't write image to new SD card
Replies: 6
Views: 4006

Re: Can't write image to new SD card

One way to do this is to get your self the live CD version of GParted. http://gparted.sourceforge.net/livecd.php which you may find comes in very useful for other jobs as well in the future. So what you do is: 1) Get a 16GB card and write your 8GB image to it. 2) Make sure it boots on a Pi but do no...
by Heater
Sun Jun 09, 2013 1:10 pm
Forum: General discussion
Topic: please help
Replies: 40
Views: 11987

Re: please help

OK good. So we have: 1) Read RFID tag and GPS coordinates from serial 2) Send it over internet to android mobile APP 3) Use a Raspberry Pi (or not)? If you know C you can pick up JavaScript very easily. Sounds crazy but one of the easist ways to get web things working is via JavaScript. Not running ...
by Heater
Sun Jun 09, 2013 11:04 am
Forum: General discussion
Topic: please help
Replies: 40
Views: 11987

Re: please help

ahmedwahdan, What subject are you hoping to graduate in, and at what level? How long have you got to complete this project? From the nature of your question it seems you know nothing of programming, and by implication nothing about serial communication, network and especially web protocols, client s...
by Heater
Sun Jun 09, 2013 10:09 am
Forum: General discussion
Topic: please help
Replies: 40
Views: 11987

Re: please help

I'm not an educator but having been hanging around varius technical forums for years I have see many questions pop up that are obviously homework problems. This issue gets even more interesting when you are on a forum that is clearly of an educational bias like this one or say the Parallax Inc. foru...
by Heater
Sat Jun 08, 2013 10:31 pm
Forum: General discussion
Topic: RPi web browsing - unusable?
Replies: 16
Views: 3446

Re: RPi web browsing - unusable?

I suggest all us Pi users stick to the good old stand by browser: https://en.wikipedia.org/wiki/Lynx_%28web_browser%29
by Heater
Sat Jun 08, 2013 9:27 pm
Forum: General discussion
Topic: RPi web browsing - unusable?
Replies: 16
Views: 3446

Re: RPi web browsing - unusable?

Yep. This issue of caching has a point though. As far as I can tell my browsers keep a copy of every page visit in cache for a quick redraw without reload when I go backwards and such. Of course that perhaps ends up being slower than downloading the whole thing again if you storage media is slow and...
by Heater
Sat Jun 08, 2013 8:17 pm
Forum: General discussion
Topic: RPi web browsing - unusable?
Replies: 16
Views: 3446

Re: RPi web browsing - unusable?

Here we have Firefox loading a more normal page: 18385 michael 20 0 1016m 313m 21m R 18.5 11.3 28:45.33 firefox 2406 root 20 0 227m 67m 8484 S 2.0 2.4 262:17.95 Xorg Clearly Xorg is not the major culprit in page rendering sluggishness on Linux. 2 percent of CPU vs 20 odd percent for Firefox.
by Heater
Sat Jun 08, 2013 7:52 pm
Forum: General discussion
Topic: RPi web browsing - unusable?
Replies: 16
Views: 3446

Re: RPi web browsing - unusable?

gkreidl, There are 2 things, that make browsing slow on the RPi:...xorg...javascript... Actually that is not true. Just now I'm logged into my Linux PC whilst someone is playing FarmVille. Here is what I see: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 18424 m 20 0 2860m 1.5g 17m R 90.5 55...
by Heater
Sat Jun 08, 2013 5:37 pm
Forum: General discussion
Topic: RPi web browsing - unusable?
Replies: 16
Views: 3446

Re: RPi web browsing - unusable?

As far as I know web browsers on the PC and the like are not GPU accelerated either. Except when it comes to things like webgl which are not very common. It is unlikely that a GPU would help rendering a typical web page or speed up the JavaScript in anyway. At some point you have to accept that the ...
by Heater
Sat Jun 08, 2013 3:48 pm
Forum: General discussion
Topic: How to post file from a rpi on a web server
Replies: 3
Views: 649

Re: How to post file from a rpi on a web server

If I wanted to move files from the Pi to a server I would run an ssh server on the server and use scp from the Pi:

Code: Select all

$ scp file_name user_name@server_address:some_directory
FTP is not secure.

Or do you mean to uplload files from a web page using web protocols and the webserver?
by Heater
Sat Jun 08, 2013 3:24 pm
Forum: Raspberry Pi OS
Topic: Memory Allocation Errors with Windows shared folders
Replies: 5
Views: 1338

Re: Memory Allocation Errors with Windows shared folders

So it was a Windows problem. No wonder we had no idea about it.
by Heater
Sat Jun 08, 2013 3:03 pm
Forum: General discussion
Topic: install and upgrade a software on RPi
Replies: 4
Views: 1051

Re: install and upgrade a software on RPi

Debian and hence Raspian are generally not using the latest version of anything. It takes time for someone to build the packages and then there has to be a lot of testing before it gets into the distro. Debian values stability over "freshness". Firstly, are you sure you need a newer version? Does it...
by Heater
Sat Jun 08, 2013 1:37 pm
Forum: General discussion
Topic: Cross compile whole Debian distro
Replies: 4
Views: 895

Re: Cross compile whole Debian distro

Pixel, I did not mean to be so negative. It's just that I have spend hundreds of hours fighting with setting up cross compilers for various platforms over the years, including ARM, sometimes you just have to as the target device does not have the OS or memory whatever to compile stuff for itself. I ...

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