At least one distributor of rtl-sdr dongles (rtl-sdr.com) added
a bias-t to their dongles which could be toggled via GPIO P0 of the
RTL2832U chip.
source: http://www.rtl-sdr.com/rtl-sdr-blog-v-3-dongles-user-guide/
Signed-off-by: Steve Markgraf <steve@steve-m.de>
This improves SDR performence for nearby channel interference.
As a sideeffect also improves dynamic range becase ADC is not overloaded
by onwanted singlas.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
So far we had 32 * 256KB which was a bit overkill,
15 are more than enough.
15 was chosen instead of 16 because at least on Linux
there seems to be a system-wide limit of 63 transfers
(when they are 256KB large), so 4 dongles can be used
on a single machine without lowering the default transfer
number.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
Thanks to Joris van Rantwijk for finding what seems to be
a hardware limitation/bug (bit 28 of the rsamp register being
forced to the value of bit 27).
Signed-off-by: Steve Markgraf <steve@steve-m.de>
Since the R820T is a power hog and gets quite hot,
this makes sense, especially when being battery-
powered.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
This allows to open a device by a name (serial number string)
that has been programmed with rtl_eeprom -s.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
We now use Hz instead of KHz for calculating the PLL
parameters, and use the actual crystal frequency in Hz,
which allows to correct the frequency error in ppm.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
This commit adds the function rtlsdr_set_direct_sampling()
which can be used to enable/disable a mode where the
RTL2832 acts as a direct sampling receiver.
This mode disables the tuner, and by attaching a long
wire, or better, a 50Ω to 200Ω transformer and a lowpass-
filter to the In-phase ADC input (pin 1 or 2 of the RTL2832,
whereas pin 1 is at the molded dot) it is possible to listen to
shortwave radio stations. The coupling capacitors can be
left in place, but for better results they should be removed.
Tuning in this mode is done with the DDC, and since the
ADC samples with 28.8 MHz, tuning is possible from 0 to
28.8 MHz.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
Changing the license of the header as well,
which had been forgotten in commit
6aec27c6d0
- "tuner_e4k: relicense driver under GPLv2+"
Signed-off-by: Steve Markgraf <steve@steve-m.de>
This adds rtlsdr_set_agc_mode() to enable/disable it.
Thanks to Leif Asbrink for finding this setting.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
The driver was taken from http://git.linuxtv.org/ and adapted
for librtlsdr. Manual gain will be added in a follow-up commit.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
We now use Hz instead of kHz for the internal
calculations, and thus improve the tuning resolution
to ~50 Hz (tested with DAB).
Signed-off-by: Steve Markgraf <steve@steve-m.de>
The driver was taken from http://git.linuxtv.org/ and adapted
for librtlsdr. Also, fc0013_set_gain() was added.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
This tool allows to check for lost samples (and thus check the USB
connection), as well as benchmark the Elonics E4000 tunable range.
(-t switch)
Signed-off-by: Steve Markgraf <steve@steve-m.de>
Usually both, the RTL and the tuner ICs use the same clock. Changing the
clock may make sense if you are applying an external clock to the tuner
or to compensate the frequency (and samplerate) error caused by the
original cheap crystal.
This commit covers all tuner drivers except of the Fitipower FC2580
