[KP4TR] connected a Raspberry Pi to a small, cheap handheld radio, allowing anyone within a few miles of his house to connect to amateur radio operators all around the world.
For the hardware, [KP4TR] is using a Raspi, a Baofeng BF-888s 400MHz – 470MHz walkie-talkie radio, a USB sound card, and a pair of transformers for the 5V and 3.7V lines. All this is tucked away in a remakably vintage-looking plate and standoff enclosure, complete with acorn nuts and an RGB LED connected to the Raspi’s GPIO to indicate whether the radio is transmitting or receiving.
The software used is SVXLink, a Linux port of the Echolink software. This app allows hams the world over to connect to very distant radios over the Internet.
You can check out the video demos of the system below.
Continue reading “Pi-Powered Radio Over IP”
[Rogal] wrote a cell phone application called ToneTool that generates audio tone sequences. It can be used to output DTMF and SelCall sequences which are used by telephone systems and radio-telecommunication hardware. The software is written in J2ME so if you have a cell phone that can run Java apps it will probably work for you. This is like a digital-age Blue-box in everyone’s pocket. But we don’t think there’s too much opportunity for the mayhem seen with the original phone phreaking.
See him generating and sending DTMF commands over an Echolink network in the video after the break.
Continue reading “DTMF and SelCall signal generator”