Pi Slow Scan TV wins 'Make' contest

The Raspberry Pi contest, sponsored by Make, attracted nearly 40 projects. The panel of judges were impressed by the range and quality of the entrants and while the competition was close, one project rose to the top, Gerrit Polder’s Slow Scan TeleVision (SSTV) Camera.

The Raspberry Pi with the PiCam is used as a wireless camera which can transmit images over long distances, usually tenths of kilometers. Images will be transmitted by amateur radio (ham-radio) using slow scan television (SSTV) on the 2 meter band (144.5 MHz).

Since the Pi can generate the HF FM signal itself, no additional electronics are needed for low power transmissions. For a little bit more power a one or two transistor amplifier will be suitable. Furthermore a low pass filter is recommended to filter out higher harmonics of the signal.

This project also contains a Python script which detects movement. Using this script, the Raspberry Pi can be used as a wireless security cam at distances far outside the range of normal WiFi networks.

Listening to D-STAR with DSD 1.7

D-STAR digital voice can now be decoded using DSD 1.7 software

Up until recently it was possible to decode D-STAR headers using either DSD 1.6 or dstar.exe and an RTL-SDR, but it was not possible to decode voice. Now amateur radio hobbyist PU2VLW has brought to our attention that the latest DSD development version 1.7 is capable of decoding D-STAR audio.

RTL-SDR - http://www.rtl-sdr.com/listening-d-star-digital-voice-dsd-1-7/

PU2VLW (Google English) - http://tinyurl.com/DecodingDSTAR

Outernet - Shortwave radio from space

Outernet is described as the modern version of shortwave radio broadcast from space

It is planned that the Outernet will consist of a constellation of hundreds of low-cost, CubeSats in Low Earth Orbit (LEO). Each satellite receives data streams from a network of ground stations and transmits that data in a continuous loop until new content is received.

In order to serve the widest possible global audience, the entire constellation utilizes UDP-based multicasting over WiFi. Although still not common, WiFi multicasting is a proven technology, especially when the data requires only one hop to reach the recipient.

Outernet claims to be able to bypass censorship, ensure privacy, and offer a universally-accessible information service at no cost to global citizens. They say lack of an Internet connection should not prevent anyone from learning about current events, trending topics, and innovative ideas.

Although Outernet's near-term goal is to provide the entire world with broadcast data, the long-term vision includes the addition of two-way Internet access for everyone - for free.

The team hope to have the first test CubeSats launched in 2015.

Outernet - https://www.outernet.is/