1. WebSDR with Raspberry Pi
Tommy Gober, N5DUX
Font: Franklin Gothic Demi

2. Poll the Audience How many have a Raspberry Pi?
How many use Linux? In shack?
How many have assembled Softrock?

3. RTL-SDR may be now be possible!
Receiver
Softrock Lite II
Center frequency of 7.159
RTL-SDR may be now be possible!

4. Software Defined Radio
Direct Conversion Receiver
I/Q signals
90° out of phase
waveform diff provides signal
demod via geometry

5. Raspberry Pi $35± Different Models Model B Also need:
5VDC power, SD, keyboard, video* wifi? case?

6. Soundcard WebSDR requires stereo input Cheap USB devices won’t do
Wolfson Audio Card ($35) from Element14
stereo in, kHz ADC

7. Drivers Element14 makes drivers available Cross compile
Raspbian Distro from Element14

8. Linux Config startup script screen WebSDR config Hostname Enable IPV6
Ensure ALSA works

9. Linux Config screen Hostname (websdr40) Enable IPV6 Ensure ALSA works
WebSDR config

10. Router Config DynDNS Router port forwarding Considerations: Security
QoS
Max users
ISP ToS

11. WebSDR with Raspberry Pi
Tommy Gober, N5DUX