Monday, September 9, 2013

How to setup Putty to do X forwarding for Linux Ubuntu and Raspberry Pi.

How to setup Putty to do X forwarding for Linux Ubuntu and Raspberry Pi. (Remote desktop your Linux)Remote control your Linux and Raspberry Pi

What is X windows forwarding on Linux?

X windows forwarding allows you to local display the applications that is running on a remote Linux server.
Install your favorite X windows server on your MS windows PC.
I will install my favorite Cygwin x windows server and will explained the steps here.

Start the x Windows server.

You Should see a X in the icon bar at the bottom of your desktop.

When done continue with the Putty installation steps here

Install Putty and then run it to get to First configuration screen below.

1) Enter the Host-name or IP of your Linux server in host Name text box.  E.G
2) Enter the Port if its not the default port 22

Putty Start-up Configuration screen

2) Click on the Connection >> SSH >> X11 Category in the tree view.

3) Save the configuration.

4) Open your new configuration.
Enter your username and password.

login as: user1's password:
Welcome to Ubuntu 12.04.3 LTS (GNU/Linux 3.5.0-23-generic i686)

 * Documentation:

245 packages can be updated.
122 updates are security updates.

*** System restart required ***
Last login: Mon Sep  9 15:32:31 2013 from$ 

5) Now see if X fording is setup on your Linux (by default it is enabled but not for the root user)
Run the command echo $DISPLAY

The value could be localhost:12.0 or 10.0

Do not su to any user otherwise your DISPLAY setting will not work.

"ls -l .Xauthority"  in the home directory to verify a file named .Xauthority exists. If so it should show permissions -rw-------

If you have to su to a different user you will have to copy the Xauthority file from your home directory to the home of the su user as well and check if the DISPLAY setting is also correct.

If you don't have a DISPLAY setting then run this command. export DISPLAY=<value from step above> 

6)Test it with  xterm or xclock

it could take some time for the xterm application window to pop up on your MS windows desktop.

and there you have it.

If you want your Raspberry Pi Full desktop and not just the app you start you could use the command on the Raspberry Pi startlxde

Thursday, September 5, 2013

ZACUBE-1 (South Africa CubeSat-1)

ZACUBE-1 (South Africa)November 21st at  07:11:29 UTC.

The amateur radio CubeSat designed and built by students at the Cape Peninsular University of Technology in Bellville.
The current launch info has lift off scheduled for November 21st at  07:11:29 UTC.
Live launch video
You should be able receive ZACUBE-1 satellite on this weSDR.

Satellite seems to be in 1k2 mode at the moment.
The keps that seems to be the best at the moment is 2013-066B (27Nov2013) from

TX power at the moment 0.5 wat.
more info at
Here is a video recording of the telemetry.

The objectives of the mission are:
1) Training of post-graduate students in Satellite Systems Engineering.
2) Earth observation using a visible band matrix imager payload and an S-Band payload data transmitter (2.4 to 2.45 GHz).
3) UHF Store & Forward system (70 cm amateur band).

  • Uplink is 145.860 MHz
  • Downlink 437.345 MHz. Both links have selectable transmission rates of 1.2 kbps or 9.6 kbps.
  • Visible band matrix imager 115200 bps L-Band to S-band data transponder. (2.4 to 2.45 GHz).
  • HF beacon 14.099 MHz Hermanus Magnetic Observatory’s Dual Auroral Radar Network antenna at SANAE base in Antarctica (The HF beacon payload on 14.099 MHz ).
To decode the telemetry of ZAcube-1 download the software from
Telemetry format

0C 16 - header
7A 61 63 75 62 65 30 31 2E - ASCII Text message00 00 19 6d 2C - Timestamp (ticks)0B 0e 2C - Battery bus voltage (volt)06 ad 2C - OBC temperature (°C)00 2E - Command counter

Telemetry decoder from
Here is some pictures from the ZACUBE-1 camera

And many more follow the link to there site
Read more about it here.