teaching machines

Booting, SSH, GUI and Compiling

September 13, 2012 by . Filed under buster.

Buster – The Beginning

Upon receiving the Rasberry PI (B) model from Dr. Johnson 8 days ago I’ve been able to accomplish a few things:

I’ll go over these in order, so to start off I’ll describe the process I had to go through to be able to boot Raspian on the Rasberry Pi device.

I was given an 8GB Transcend SDHC card and the Rasberry Pi device itself. I supplied the power source, a small wall-wart from my Motorola Atrix 4G phone, USB power cable, HDMI cable and personal laptop and display. I started by Googling around for the distribution and found a place to download it here: http://downloads.raspberrypi.org/images/raspbian/2012-08-16-wheezy-raspbian/2012-08-16-wheezy-raspbian.zip . To write it to the SD card from my laptop running Windows 7 (64-bit) I had to download the program “Win 32 Disk Imager” found here: http://www.softpedia.com/get/CD-DVD-Tools/Data-CD-DVD-Burning/Win32-Disk-Imager.shtml. After inserting the SD card into my laptop’s card reader, installing Win 32 Disk Imager and downloading the Raspian .zip file, I was ready to actually put the OS on the card.

Imaging was easy, I selected the file I wanted to put on the Card, what drive letter the card was, clicked the “Write” button Win 32 Disk Imager, waited a bit and that was it.

So I inserted the SD card into the device, connected my Das Keyboard, Logitech G500 mouse to the USB ports and Sharp TV via HDMI, lastly I powered on. And I got a picture!

So at this point I had booted Raspian.

So all was good until I tried to SSH into another server, I decided this was a good way to test network connectivity after having plugged in an Ethernet cord to the device AFTER booting. It didn’t work. So I decided it would be a good idea to restart the device in attempt to get network connectivity.

After the reboot, I saw the computer had obtained an IP address and I was able to SSH into andy.cs.uwec.edu, one of UWEC’s Department of Computer Science’s Linux boxes. It worked!

The last thing I did that night was check out the GUI. So I typed “startx” into the shell prompt. I was greeted with the dark pink raspberry with two green leaves and a white background, pretty. So I immediately noticed the “Python Games” icon and decided that would be a good place to start. I played the “Bejeweled” knockoff and noticed I wasn’t getting very good frame rates. My guess is that the CPU was doing the heavy lifting of coloring the pixels and the GPU was just being used to send them to the screen. After that I put it away for a week.

Picture of my setup when I was trying to access the device via SSH:

“Just compile something”

This was the hardest “Hello World” program I have ever written. It started with the # sign. So the default “Shift+2” key combination wrote the European “L” shaped pound sign, and not this one: “#”. I started smashing keys and eventually found that the button above “Enter” when pressed in combination with the “Shift” modifier key produced “#”. OK so there’s my first character. Include <stdio.h> went well.

#include <stdio.h>

int main() {

printf( UH OH! Where is my double quote? “ ?? the (Shift+’) was procuding the at symbol, “@” which is normally (Shift+2), so after more trial and error I found that (Shift+2) was actually the double quote. Forward we go, that is until I have to add the \n right before the closing double quote. I still haven’t found the backslash key/key combination. So I used

fflish(stdout);

return 0;

}

But I was able to compile and get my resulting “Hello World”