New SDR dongle received but cannot get it to work

This is merely a historical archive of years 2008-2021, before the migration to mailman3.

A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/osmocom-sdr@lists.osmocom.org/.

Cinaed Simson cinaed.simson at gmail.com
Tue Oct 24 03:12:04 UTC 2017


On 10/23/2017 03:30 PM, John wrote:
> Cinead,
> 
> My apologies for this and thanks for your clarification. I have followed
> thorough with the suggestions made by yourself and Marcus, including
> installing the provided ruleset and checking the device power usage. I
> have also tried another USB cable and another computer. However I did
> miss the point you made about leaving off the '-t' in the detail of your
> original response.
> 
> Also, I have been responding to the messages I received from the mailing
> list thinking that I was responding to the mailing list, but it seems
> that I have actually been responding directly to individuals. This was
> unintentional and I apologise, but the e-mail 'From:' header on the
> messages I have received from the list shows the e-mail address of the
> individual who sent the message rather than the mailing list address
> which seems rather unusual. It means I have to manually copy in the
> 'osmocom-sdr at lists.osmocom.org' address into the 'To:' header each time
> I reply, as I have done in this case.
> 
> So this is what I get with just rtl_test:
> 
> $ rtl_test
> Found 1 device(s):
>   0:  Realtek, RTL2838UHIDIR, SN: 00000001
> 
> Using device 0: Generic RTL2832U OEM
> usb_claim_interface error -5
> Failed to open rtlsdr device #0.

That's IO error.

> 
> Its the same whether I run it as user or with root privileges. I don't> see the dvb_usb_rtl28xxu kernel driver being loaded in the output of
lsmod.

You shouldn't have seen it - it should have been blacklisted.

Try

  lsmod | grep rt

-- Cinaed

> 
>> Okay, if you send another email with output of
>>
>>   rtl_test -t
>>
>> I'm going to blacklist your email address.
>>
>> Use
>>
>>   rtl_test
>>
>> to run the test for a 2832.
>>
>> Use
>>
>>   rtl_test -t
>>
>> to run the test for a 2838.
>>
>> Type
>>
>>   rtl_test --help
>>
>> It clearly indicates the -t flag in rtl_test is for the E4000.
>>
>> The system claims you have a 2832 - and not a 2838 or E4000 - so get
>> over it.
>>
>> Clear enough?
>>
>>
>>> Found 1 device(s):
>>>   0:  Realtek, RTL2838UHIDIR, SN: 00000001
>>>
>>> Using device 0: Generic RTL2832U OEM
>>> Found Rafael Micro R820T tuner
>> This is your device:
>>
>>   Using device 0: Generic RTL2832U OEM
>>   Found Rafael Micro R820T tuner
>>
>> It clearly states it's a RTL2832 device with a Rafael Micro R820T tuner.
>>
>>
>>> r82xx_write: i2c wr failed=-1 reg=1a 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.
>>   No E4000 tuner found, aborting.
>>
>> This statement clearly indicates your device is NOT a E4000 - or a 2838.
>>
>>> 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
>>>
>> Did you remove the your home brewed file from /etc/udev/rules.d? If not
>> then remove it and reboot.
>>
>> Send me a listing of
>>
>>   /etc/modprobe.d
>>
>> and the contents of the file you're using to blacklist the RTL devices.
>>
>> Also, update your system listing and install the following
>>
>>   apt-get update
>>   apt-get install librtlsdr-dev
>>   apt-get install libusb-1.0-0-dev
>>
>> What type of computer are you using? If you're using a computer with
>> more than 1 USB port, try plugging the dongle into another port.
>>
>> It's possible the RTL dongle is bad or you have problems with your USB
>> ports - but you need to eliminate system possible system software issues
>> first.
>>
>> -- Cinaed
>>
>>
>>>> Cinaed Simson <mailto:cinaed.simson at gmail.com>
>>>> 22 October 2017 03:53
>>>> 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
>>>>>
>>>>>
>>>>>
>>>> John <mailto:subs at qcontinuum.plus.com>
>>>> 21 October 2017 17:08
>>>> 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
>>>> 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
>>>>
>>>>
>>>>
>>> -- 
>>> John
>> John <mailto:subs at qcontinuum.plus.com>
>> 22 October 2017 17:02
>> Cinead,
>>
>> Thank you for this information and the ruleset. I have been looking
>> for an 'official' ruleset to try, but couln't find one. For whatever
>> reason a ruleset was not automatically installed. However, I installed
>> the software from the repository via apt-get rtl-sdr rather than
>> downloading and compiling.
>>
>> I have now removed the file I created and installed the one you
>> provided. Unfortunately it made no difference. I initially used just
>> the two udev commands to re-initialise udev, but then also rebooted
>> for good measure.
>>
>> You observation  is interesting however, as this device identifies
>> itself as vendorID '0bda' and deviceID '2838' in lsusb:
>>
>> Bus 002 Device 012: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T
>>
>> and likewise in dmesg:
>>
>> [  622.683133] usb 2-1.6: new high-speed USB device number 12 using
>> ehci-pci
>> [  622.787405] usb 2-1.6: New USB device found, idVendor=0bda,
>> idProduct=2838
>> [  622.787410] usb 2-1.6: New USB device strings: Mfr=1, Product=2,
>> SerialNumber=3
>> [  622.787413] usb 2-1.6: Product: RTL2838UHIDIR
>> [  622.787415] usb 2-1.6: Manufacturer: Realtek
>> [  622.787417] usb 2-1.6: SerialNumber: 00000001
>>
>> As you point out however, it has an R820T tuner, which has now been
>> visually confirmed by the markings on the IC, so if RTL and other
>> programs are expecting an E4000 then this is probably not going to
>> work. I expect that the device will always match the second rule in
>> the ruleset and it seems that it is possible to access the device in
>> user mode. However I'm not sure how to get around the expectations of
>> the driver? Curiously the second rule refers to 'Newsky TV28T
>> (E4000/R820T)' which mentions both radios for the same product ID, so
>> then one might expect that the driver looks for either and tries to
>> determine which it is?
>>
>> rtl_test seemed to identify it correctly - 'Found Rafael Micro R820T
>> tuner' but then then also fails to find an E4000 radio 'No E4000 tuner
>> found, aborting.' so my assumption was that it was trying to determine
>> which one was present, but then I am not familiar with the code.
>>
>> So the question in my mind is whether rtl_test is indeed making a
>> determination and the errors are due to a problem communicating with
>> the device, or whether it is looking for E4000 hardware as you say and
>> failing because it is sending inappropriate commands. If the latter,
>> then is there a way to fool it, e.g. by temporarily changing the
>> device ID or forcing the driver to communicate with an RT820T radio?
>>
>> I did find the -d flag and tried rtl_test -d0 but this yielded a
>> similar response, although it did not identify any tuner and simply
>> returned 'No supported tuner found'.
>>
>> The full output is below:
>>
>> $ rtl_test -t
>> 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=1a 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
>>
>>
>>
>>
>>
>> Cinaed Simson <mailto:cinaed.simson at gmail.com>
>> 22 October 2017 03:53
>> 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
>>>
>>>
>>>
>> John <mailto:subs at qcontinuum.plus.com>
>> 21 October 2017 17:08
>> 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
>> 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
>>
>>
>>
> 
> -- 
> John




More information about the osmocom-sdr mailing list