WebSDR withRaspberry Pi

Tommy Gober, N5DUXFont: Franklin Gothic Demi

Poll the Audience

How many have a Raspberry Pi?

How many use Linux? In shack?

How many have assembled Softrock?

Receiver

Softrock Lite II

Center frequency of 7.159

RTL-SDR may be now be possible!

Software Defined Radio

Direct Conversion Receiver

I/Q signals 90° out of phase waveform diff provides signal demod via geometry

Raspberry Pi

$35± Different Models Model B Also need:

5VDC power, SD,keyboard, video*wifi? case?

Soundcard

WebSDR requires stereo input

Cheap USB devices won’t do Wolfson Audio Card ($35) from Element14

stereo in, 192kHz ADC

Drivers

Element14 makes drivers available

Cross compile Raspbian Distro from Element14

Linux Config

startup scriptscreenWebSDR configHostnameEnable IPV6Ensure ALSA works

Linux Config

screen Hostname (websdr40) Enable IPV6 Ensure ALSA works WebSDR config

Router Config

DynDNS Router port forwarding Considerations:

Security QoS Max users ISP ToS

WebSDR withRaspberry PiTommy Gober, N5DUX