On 10/21/2017 09:08 AM, John wrote:
Hello,
I am new to this list and to SDR radio. I have purchased an SDR dongle
but am having trougble getting it to work. The dongle was described as
an RTL8232U/R820T2 device. I am running on Linux MINT version 18.2 and
lsusb detects the device as follows:
Bus 002 Device 051: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T
Is it an RTL2832U or an RTL2838? I'm not really sure.
From research it seems that It seems like the fist order of business is
to blacklist the kernel driver? So I have done this by adding a
backlist-rtl.conf file to /etc/modprobe.d and rebooted the computer. I
have also added a rules file to /etc/udev/rules.d with the following
content:
# Realtek Semiconductor Corp. RTL2838 DVB-T
SUBSYSTEMS=="usb", ATTRS{idVendor}=="0bda",
ATTRS{idProduct}=="2838",
MODE:="0666", GROUP="adm", SYMLINK+="rtl_sdr"
I can now access the device in user mode without permission errors so I
assume that this is working OK.
So my next step was to run rtl_test -t. The output I got contained
errors.If I then try to run any sdr software such as rtl_fm or gqrx, the
device is reset and the application fails to run. Subsequentlly running
'rtl_test -t' gives:
No supported devices found.
Even running rtl_test-t sometimes does the same so i'm not sure whether
the device is 'dropping out' of its own accord.
I am wondering whether the current crop of devices are supported? Or is
this a configuration problem?
The output from rtl_test:
rtl_test -t
The output from rtl_test indicates it's a "2832" - but your home brewed
rule is probing for a "2838" which is the E4000.
I recommend you install the enclosed udev rules.
After you copy them to /etc/udev/rules.d, try
udevadm control --reload
udevadm trigger
If that doesn't work, reboot.
The correct rules should have been installed when you installed the
sofware - so you may have other problems.
And use
rtl_test
The command
rtl_test -t
is for the E4000 - and your enclosed error message indicates it's not E4000.
-- Cinaed
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001
Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
r82xx_write: i2c wr failed=-1 reg=13 len=7
r82xx_write: i2c wr failed=-1 reg=0c len=1
r82xx_init: failed=-1
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7
16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1
43.4 43.9 44.5 48.0 49.6
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
r82xx_write: i2c wr failed=-1 reg=0a len=1
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
WARNING: Failed to set sample rate.
No E4000 tuner found, aborting.
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
rtlsdr_demod_write_reg failed with -1
rtlsdr_demod_read_reg failed with -1
rtlsdr_write_reg failed with -1