The rad1o is the badge of the Chaos Communication Camp 2015 (CCCamp15).
The rad1o badge contains a full-featured SDR (software defined radio)
half-duplex transceiver, operating in a frequency range of about 50 MHz
- 4000 MHz, and is software compatible to the HackRF.
See https://rad1o.badge.events.ccc.de for more information.
Both libhackrf and hackrf_transfer are using boolean flag named
"do_exit" which is not static. This is problematic because the flag is
used for different things. This patch fixes the problem by making the
flag static in both places.
When '-' is used for filename, write samples to stdout when receiving or
read samples from stdin when transmitting. This allows using
hackrf_transfer in shell pipes with tools like csdr.
User info messages are written to stderr.
Intro:
Some of the Hackrf board use a bad performance crystal, it will cause some program can't work---such as GNSS(GPS) simulation. Most GPS receiver can capture the satellite
when the doppler within 10KHz, but 10ppm bias of the crystal will cause 15Khz doppler. And my hackrf board uses a 16ppm crystal :( normal
Of course, I can replace the crystal or use a external clock. But for most people, add a ppm correct function to hackrf_transfer is useful.
How to use:
1, measure your crystal's error
You can use a precision counter to measure it.
Connect the hackrf's "clock out" to the counter, get the frequency Fh, then ,
ppm = (Fh - 10000000)/10
You can use a standard clock source such as OCXO, TCXO, or Atom Clock, and a counter
to measure the crystal error too.
2, add an argument "-C ppm " when you use hackrf_transfer.
Eg. , your crystal error is -8ppm ( In other words , your clock is slower than the standard clock), then you should add "-C -8" follow the hackrf_transfer command.
Hope you can understand my poor English:)
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Thanks to Michael Ossmann;
Thanks to Jared Boone ;
Thanks to Benjamin Vernoux ;
Thanks to GPL.
