Rudma Tek

Understanding the building blocks of our earth through technology and where.

By incorporating software, hardware and procedures we can create spatial systems to better understand our planet, create information to support better decisions promoting a sustainable future.

We advance the spatial industry with innovative Geographic Information Systems (GIS).

NationalMap and Open Data

Australia has a National Map and it is better than a biscuit.

Rumour has it that the National Map started shortly after a bit of jealousy by a federal member towards the brilliant Queensland Globe.

Starting with being Open Source (Queensland Globe is based on a few proprietary tools) National Map has grown rapidly and now displays a large percentage of the 7400 discoverable datasets on

The National Map can be found here:

Not just a pretty face either. You can connect another GIS web-service to it or display file-based GIS data. The opposite is true as well. Each dataset in the National Map lists the data source it is connected to and this link can be used in your own GIS app – be it a web site, mobile app or full blown desktop GIS such as ArcGIS Desktop.

Please explore the National Map or contact us to assist with linking the data to your project or explaining some of the technologies involved.

Garmin Virb Elite (GPS equipped action cam)

After searching the internet I had to resort to scalpels and multimeters to define the pinout of a Garmin Virb action cam.


These cameras are well specced and are equipped with GPS and Ant+. The camera can be acquired from Johnny Appleseed GPS at this link.
In order to connect the camera to other devices such On Screen Display (OSD) for video transmitters on UAVs or small vehicles a slightly more efficient cable needs to be used compared to the Garmin issued version (link)


The 4-to-1 cable provides 3.5 mm stereo input for an external mic, RCA composite video output, 3.5 mm stereo audio out and mini-USB port.

The aim is to come up with a small and light cable containing only the essentials. Garmin uses a resistor connected between one of the data lines and USB Ground to determine if the camera should switch to external view mode. The connector is a Mini USB B but equipped with 10 pins. Connectors can be obtained from a variety of sources on eBay or other sites. ReadyMadeRC have them for US$0.89 (link)

Pin 1: USB Power (5v)
Pin 2: USB Data +
Pin 3: USB Data -
Pin 4: Garmin Video Enable 2.2kOhm resistor to Pin 5
Pin 5: USB Ground (Garmin Video Ground)

Pin 6: Garmin Audio Out
Pin 7: Garmin Audio Ground (Mic Input + Audio Output)
Pin 8: Garmin Mic Input channel 1
Pin 9: Garmin Mic Input channel 2
Pin 10: Garmin Video Out

After a bit of testing I now have a breakout cable about 3cm long and the diameter of the usb connector ready to connect to another external device.


GIS Brambles

Food for thought from a quant little River Bar in Brisbane

Food for thought from a quant little River Bar in Brisbane

Here follows the news. Or, as it will be known from now on, GIS Brambles.

They are very taste little morsels and food for thought however - be aware that there might be a thorn here and there.




© Rudma Tek Pty Ltd 2015