libusb-devel

Controlling and reading a usb radio

[Deron <de...@pa...>]

Hello,

I hope this is an appropriate things to post here. I have an AlertFM usb 
radio that is "windows only" that I want to use on my Ubuntu server. The 
plan is to set it up to listen for EAS warnings on our local radio 
station. (We live a long way from civilization and don't always have the 
TV on). If I can get the audio stream, I can do the rest easy enough 
(I've got that part written and tested using recordings of EAS audio 
messages).

Anyway, I have a windows computer and captured some channel changing 
data using their software, and digging around I found this software 
which actually recommends hidapi for HID devices. No problem, I have 
that installed along with libusb and I think I even have it changing 
channels (one report sets the channel, and another reads back the 
current channel. Still an input report I can't seem to grab which gives 
signal strength data etc, but I could live without that.)

What I don't have now is the audio stream. I'm not very familiar with 
USB, so this is a really basic question, but what do I do to read that 
data? I'm guessing that hidapi won't be able to read that data, and 
somehow need to mix in calls with libusb? I've not had much luck finding 
sample applications for hidapi, and if someone could just nudge me in 
the correct direction I would appreciate it or even basic info on USB 
that would fluff out my knowledge without have to read an encyclopedia 
on USB.

Thanks!

Deron

Re: Controlling and reading a usb radio

[Peter S. <pe...@st...>]

Hi!

Deron wrote:
> What I don't have now is the audio stream. I'm not very familiar with 
> USB, so this is a really basic question, but what do I do to read that 
> data?

This is highly device-specific. The process is to reverse-engineer
how the device communicates with the PC. You may have to learn a fair
bit of USB details.


> if someone could just nudge me in the correct direction I would
> appreciate it or even basic info on USB that would fluff out my
> knowledge without have to read an encyclopedia on USB.

If you send the output of lsusb -v for the device to this list, we
may be able to help you find the correct process.

If you want, you can also check out my USB intro talk which goes into
some light technical detail about the bus.

Slides: http://events.ccc.de/congress/2010/Fahrplan/events/4234.en.html
MPEG-4: http://mirror.fem-net.de/CCC/27C3/mp4-h264-HQ/27c3-4234-en-usb_and_libusb.mp4
Flash: http://youtu.be/uBBE2gihv5I

And feel free to stop by #libusb on freenode for some live
discussion.


//Peter

Re: Controlling and reading a usb radio

[Deron <de...@pa...>]

On 5/7/12 10:48 AM, Peter Stuge wrote:
> Hi!
>
> Deron wrote:
>> What I don't have now is the audio stream. I'm not very familiar with
>> USB, so this is a really basic question, but what do I do to read that
>> data?
> This is highly device-specific. The process is to reverse-engineer
> how the device communicates with the PC. You may have to learn a fair
> bit of USB details.
>
>
>> if someone could just nudge me in the correct direction I would
>> appreciate it or even basic info on USB that would fluff out my
>> knowledge without have to read an encyclopedia on USB.
> If you send the output of lsusb -v for the device to this list, we
> may be able to help you find the correct process.


This is what I get:


Bus 004 Device 002: ID 12cf:7111
Device Descriptor:
   bLength                18
   bDescriptorType         1
   bcdUSB               1.10
   bDeviceClass            0 (Defined at Interface level)
   bDeviceSubClass         0
   bDeviceProtocol         0
   bMaxPacketSize0        64
   idVendor           0x12cf
   idProduct          0x7111
   bcdDevice            1.00
   iManufacturer           1 Axentia Technologies AB
   iProduct                2 ALERT FM Radio
   iSerial                 0
   bNumConfigurations      1
   Configuration Descriptor:
     bLength                 9
     bDescriptorType         2
     wTotalLength          145
     bNumInterfaces          3
     bConfigurationValue     1
     iConfiguration          0
     bmAttributes         0x80
       (Bus Powered)
     MaxPower              100mA
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       0
       bNumEndpoints           0
       bInterfaceClass         1 Audio
       bInterfaceSubClass      1 Control Device
       bInterfaceProtocol      0
       iInterface              0
       AudioControl Interface Descriptor:
         bLength                 9
         bDescriptorType        36
         bDescriptorSubtype      1 (HEADER)
         bcdADC               1.00
         wTotalLength           43
         bInCollection           1
         baInterfaceNr( 0)       1
       AudioControl Interface Descriptor:
         bLength                12
         bDescriptorType        36
         bDescriptorSubtype      2 (INPUT_TERMINAL)
         bTerminalID             1
         wTerminalType      0x0710 Radio Receiver
         bAssocTerminal          0
         bNrChannels             2
         wChannelConfig     0x0003
           Left Front (L)
           Right Front (R)
         iChannelNames           0
         iTerminal               0
       AudioControl Interface Descriptor:
         bLength                13
         bDescriptorType        36
         bDescriptorSubtype      6 (FEATURE_UNIT)
         bUnitID                 2
         bSourceID               1
         bControlSize            2
         bmaControls( 0)      0x01
         bmaControls( 0)      0x00
           Mute
         bmaControls( 1)      0x00
         bmaControls( 1)      0x00
         bmaControls( 2)      0x00
         bmaControls( 2)      0x00
         iFeature                0
       AudioControl Interface Descriptor:
         bLength                 9
         bDescriptorType        36
         bDescriptorSubtype      3 (OUTPUT_TERMINAL)
         bTerminalID             3
         wTerminalType      0x0101 USB Streaming
         bAssocTerminal          0
         bSourceID               2
         iTerminal               0
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        1
       bAlternateSetting       0
       bNumEndpoints           0
       bInterfaceClass         1 Audio
       bInterfaceSubClass      2 Streaming
       bInterfaceProtocol      0
       iInterface              0
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        1
       bAlternateSetting       1
       bNumEndpoints           1
       bInterfaceClass         1 Audio
       bInterfaceSubClass      2 Streaming
       bInterfaceProtocol      0
       iInterface              0
       AudioStreaming Interface Descriptor:
         bLength                 7
         bDescriptorType        36
         bDescriptorSubtype      1 (AS_GENERAL)
         bTerminalLink           3
         bDelay                  0 frames
         wFormatTag              1 PCM
       AudioStreaming Interface Descriptor:
         bLength                11
         bDescriptorType        36
         bDescriptorSubtype      2 (FORMAT_TYPE)
         bFormatType             1 (FORMAT_TYPE_I)
         bNrChannels             2
         bSubframeSize           2
         bBitResolution         16
         bSamFreqType            1 Discrete
         tSamFreq[ 0]        96000
       Endpoint Descriptor:
         bLength                 9
         bDescriptorType         5
         bEndpointAddress     0x83  EP 3 IN
         bmAttributes            5
           Transfer Type            Isochronous
           Synch Type               Asynchronous
           Usage Type               Data
         wMaxPacketSize     0x0200  1x 512 bytes
         bInterval               1
         bRefresh                0
         bSynchAddress           0
         AudioControl Endpoint Descriptor:
           bLength                 7
           bDescriptorType        37
           bDescriptorSubtype      1 (EP_GENERAL)
           bmAttributes         0x00
           bLockDelayUnits         2 Decoded PCM samples
           wLockDelay              0 Decoded PCM samples
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        2
       bAlternateSetting       0
       bNumEndpoints           2
       bInterfaceClass         3 Human Interface Device
       bInterfaceSubClass      0 No Subclass
       bInterfaceProtocol      0 None
       iInterface              0
         HID Device Descriptor:
           bLength                 9
           bDescriptorType        33
           bcdHID               1.11
           bCountryCode            0 Not supported
           bNumDescriptors         1
           bDescriptorType        34 Report
           wDescriptorLength     203
          Report Descriptors:
            ** UNAVAILABLE **
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0040  1x 64 bytes
         bInterval              10
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x02  EP 2 OUT
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0040  1x 64 bytes
         bInterval               1
Device Status:     0x0000
   (Bus Powered)


> If you want, you can also check out my USB intro talk which goes into
> some light technical detail about the bus.

Thanks! Just what I'm looking for!

>
> Slides: http://events.ccc.de/congress/2010/Fahrplan/events/4234.en.html
> MPEG-4: http://mirror.fem-net.de/CCC/27C3/mp4-h264-HQ/27c3-4234-en-usb_and_libusb.mp4
> Flash: http://youtu.be/uBBE2gihv5I
>
> And feel free to stop by #libusb on freenode for some live
> discussion.

Once I get a little better grip on this where I can ask more intelligent 
questions, will. Thanks! If any of the above output points to something 
I should be reading up on, please let me know. Also, here is a little of 
the output from USBlyzer demo. Since they just keep coming, I presume 
this is the actual audio data.

URB  1294-1233  16:06:21.806  2.415316 s  118.542 ms  Isoch Transfer  
3844 bytes data  80 DA 80 D9 00 D9 C0 D7...  in  01:01:83  8AC78030h  
USBPDO-2  usbhub  8481B768h  Success (Success)

00000000  80 DA 80 D9 00 D9 C0 D7 40 D7 80 D6 00 D7 80 D7  ........@.......
00000010  80 D7 C0 D6 00 D7 C0 D6 00 D7 C0 D6 40 D6 00 D6  ............@...
00000020  80 D6 80 D5 00 D5 80 D3 80 D3 80 D3 00 D4 80 D3  ................
00000030  00 D3 80 D2 80 D3 00 D4 C0 D4 40 D5 40 D6 40 D7  ..........@.@.@.
00000040  80 D8 80 D9 C0 DA 40 DB 00 DC C0 DC 80 DD C0 DD  ......@.........
00000050  80 DE 00 DF 00 E0 80 E0 00 E1 80 E1 C0 E1 00 E3  ................
00000060  80 E3 C0 E3 C0 E3 C0 E4 40 E5 C0 E5 80 E6 80 E6  ........@.......
...


Thanks again!

Deron

Re: Controlling and reading a usb radio

[François R. <re...@fr...>]

On 07/05/2012 20:58, Deron wrote:


>       bInterfaceClass         1 Audio
>       bInterfaceSubClass      1 Control Device
[...]
>       bInterfaceClass         1 Audio
>       bInterfaceSubClass      2 Streaming
[...]

Those two interfaces are standard USB classes, meaning a generic usb
audio driver should be able to handle it already.

>       bInterfaceClass         3 Human Interface Device
>       bInterfaceSubClass      0 No Subclass

That's just the interface to control the parameters (like the tuner
frequency) AFAIK.

François.

Re: Controlling and reading a usb radio

[Deron <de...@pa...>]

On 5/7/12 1:28 PM, François Revol wrote:
> On 07/05/2012 20:58, Deron wrote:
>
>
>>        bInterfaceClass         1 Audio
>>        bInterfaceSubClass      1 Control Device
> [...]
>>        bInterfaceClass         1 Audio
>>        bInterfaceSubClass      2 Streaming
> [...]
>
> Those two interfaces are standard USB classes, meaning a generic usb
> audio driver should be able to handle it already.
>
>>        bInterfaceClass         3 Human Interface Device
>>        bInterfaceSubClass      0 No Subclass
> That's just the interface to control the parameters (like the tuner
> frequency) AFAIK.
>
> François.
>

Thanks for the info. What would be the easiest way to pull audio data 
from it then?

Deron

Re: Controlling and reading a usb radio

[Peter S. <pe...@st...>]

Deron wrote:
> >>        bInterfaceClass         1 Audio
> >>        bInterfaceSubClass      2 Streaming
> >
> > Those two interfaces are standard USB classes, meaning a generic
> > usb audio driver should be able to handle it already.
> 
> Thanks for the info. What would be the easiest way to pull audio
> data from it then?

What do you want to do with the audio data?

You do not need to consider the fact that this is a USB device at all
beyond the interaction with the HID class interface, the device
appears as a sound card in your system. Try:

cat /proc/asound/cards

Run alsamixer or similar to set mixer controls, and an audio
recording software to record audio.


//Peter

Re: Controlling and reading a usb radio

[Deron <de...@pa...>]

On 5/7/12 4:13 PM, Peter Stuge wrote:
> Deron wrote:
>>>>         bInterfaceClass         1 Audio
>>>>         bInterfaceSubClass      2 Streaming
>>> Those two interfaces are standard USB classes, meaning a generic
>>> usb audio driver should be able to handle it already.
>> Thanks for the info. What would be the easiest way to pull audio
>> data from it then?
> What do you want to do with the audio data?
>
> You do not need to consider the fact that this is a USB device at all
> beyond the interaction with the HID class interface, the device
> appears as a sound card in your system. Try:
>
> cat /proc/asound/cards
>
> Run alsamixer or similar to set mixer controls, and an audio
> recording software to record audio.
>
>
> //Peter
>

I guess I know less about Linux audio then I do USB!

Indeed, it shows:

  1 [Radio          ]: USB-Audio - ALERT FM Radio
                       Axentia Technologies AB ALERT FM Radio at 
usb-0000:00:1a.1-1, full speed

I realize this may be beyond the knowledge of this list, but I'll 
explain anyway. I'm just looking for the pcm audio stream (be it 16bit, 
2 channel or whatever) so that my code can look for the audio tones that 
precede the EAS (the Emergency Alert System used in Canada and the US to 
broadcast severe weather warnings and other emergency notifications) and 
act accordingly. So opening a device/pipe is perfectly acceptable. 
Recording to disk and then checking it after the fact would be a bit 
difficult, but I suppose the tools might let me pipe it to my 
application(?).

I'm guessing I need to look into ALSA?

Deron

Re: Controlling and reading a usb radio

[Peter S. <pe...@st...>]

Deron wrote:
> Indeed, it shows:
> 
>   1 [Radio          ]: USB-Audio - ALERT FM Radio
>                        Axentia Technologies AB ALERT FM Radio at 
> usb-0000:00:1a.1-1, full speed
> 
> I realize this may be beyond the knowledge of this list, but I'll
> explain anyway. I'm just looking for the pcm audio stream (be it 
> 16bit, 2 channel or whatever) so that my code can look for the   
> audio tones that precede the EAS (the Emergency Alert System used
> in Canada and the US to broadcast severe weather warnings and other
> emergency notifications) and act accordingly. So opening a
> device/pipe is perfectly acceptable.
..
> I'm guessing I need to look into ALSA?

Yes. You will find a large number of programs which work with audio
input on Linux systems.

A simple capture example is:
http://equalarea.com/paul/alsa-audio.html#captureex

Depending on what analysis you need to perform to match the emergency
audio signature there may also exist many helpful tools and libraries
already. Since it's radio I expect you'll want to have a bit of fuzz.


//Peter

Re: Controlling and reading a usb radio

[Hans de G. <hde...@re...>]

Hi,

On 05/07/2012 05:10 PM, Deron wrote:
> Hello,
>
> I hope this is an appropriate things to post here. I have an AlertFM usb
> radio that is "windows only" that I want to use on my Ubuntu server. The
> plan is to set it up to listen for EAS warnings on our local radio
> station. (We live a long way from civilization and don't always have the
> TV on). If I can get the audio stream, I can do the rest easy enough
> (I've got that part written and tested using recordings of EAS audio
> messages).
>
> Anyway, I have a windows computer and captured some channel changing
> data using their software, and digging around I found this software
> which actually recommends hidapi for HID devices. No problem, I have
> that installed along with libusb and I think I even have it changing
> channels (one report sets the channel, and another reads back the
> current channel. Still an input report I can't seem to grab which gives
> signal strength data etc, but I could live without that.)
>
> What I don't have now is the audio stream. I'm not very familiar with
> USB, so this is a really basic question, but what do I do to read that
> data? I'm guessing that hidapi won't be able to read that data, and
> somehow need to mix in calls with libusb? I've not had much luck finding
> sample applications for hidapi, and if someone could just nudge me in
> the correct direction I would appreciate it or even basic info on USB
> that would fluff out my knowledge without have to read an encyclopedia
> on USB.

I see that you've already gotten several useful replies further in the
thread. So it looks like getting the audio from the device is a solved
problem, which only leaves the tuning. Tuning normally is handled
by v4l2 kernel driver.

Chances are that your device is using the si470x chipset, as that uses
a usb-audio class interface for the audio and a hid interface for
tuning...

To test this you would need to do the following (as root):

1) plug in the device
2) do dmesg, you should see something like this in there:
usb 2-1.5: New USB device found, idVendor=12cf, idProduct=7111
Note the 2-1.5
3) "cd /sys/bus/usb/drivers/usbhid"
4) "ls"
You should see a symlink in there starting with the same prefix as in the
dmesg, followed by :1.2, ie: "2-1.5:1.2", then do:
5) "echo '2-1.5:1.2' > unbind"
Replacing 2-1.5:1.2 with the address string for your device
6) "modprobe radio-usb-si470x"
7) "cd /sys/bus/usb/drivers/radio-si470x"
8) "echo '0x12cf 0x7111' > new_id"
9) ls, now the 2-1.5:1.2 like string should be there, if not
    see "dmesg" for errors :|
10) "ls /dev/radio*"
If there is a radio device there things seem to be working!

Now start a program recording / looping back sound from
the alsa device for the usb-stick, and then start a radio
tuning program, for example the very simple "radio" app
from xawtv.

###

If the above does not work, it looks like you do need to write
some software to drive the device yourself after all. IMHO the end
result of this project would be to write a v4l2 kernel driver.

For starters we can write a little libusb program, but once we've
put in that effort why not go all the way and make it usable as a
normal/standard radio device under Linux?

The first step would be to catch some USB-traces of windows setting
the frequency, or iow windows doing some tuning to a radio station.

The way to do that now a days is to start windows inside a vm under Linux
and then redirect the usb device to the windows vm.

When you've the device working inside a windows vm, then:
-figure out on which usb bus the device sits (lsusb will tell you this)
-shutdown the windows vm
-unplug the device
-start wireshark as root and ignore the security warning, it is not really
  relevant when using wireshark to monitor usb devices
-tell wireshark to record usb transfers on the bus the device was on
-re-plug in the device, this needs to happen after starting wireshark,
  so that wireshark sees the usb device descriptors come past and can
  thus automatically load the right protocol dissectors
-write down where in the log wireshark now is, as everything up till this
  point was send by the standard linux hid and audio drivers
-start the vm and redirect the device to it
-write down where in the log wireshark now is, as everything up till this
  was windows initialization which is likely not interesting
-start the windows radio app, look in the wireshrak log for any HID messages,
  these are likely doing the tuning
-tune to a certain frequency if possible (ie no auto tuning, but pick a fixed freq.),
  write down where in the log you are, and what frequency you tuned to
-tune to a another frequency if possible (ie no auto tuning, but pick a fixed freq.)
  write down where in the log you are, and what frequency you tuned to
-stop the windows radio app
-stop wireshark capturing usb packets
-save the capture in wireshark!

And then you can go and try to figure things out from the capture. Note besides
a libusb developer I'm also a v4l2 developer and have reverse engineered quite
a few usb devices. This sounds like a fun little project and I would like to help,
which requires me getting my hands on such a device...

Regards,

Hans

Re: Controlling and reading a usb radio

[Hans de G. <hde...@re...>]

Hi,

<snip snip>

On 05/13/2012 06:29 AM, Deron wrote:
> On 5/8/12 3:55 AM, Hans de Goede wrote:
>> Chances are that your device is using the si470x chipset, as that uses
>> a usb-audio class interface for the audio and a hid interface for
>> tuning...
>
> I took it apart awhile ago, and it is using an si part, but I don't recall that being the number. I'll have to find my notes...
>
> Ok, best as I can see here are the number from the si chip is:
>
> silabs
> f321
> ecnab3
> o741+
>
>> To test this you would need to do the following (as root):
>>
>> 1) plug in the device
>> 2) do dmesg, you should see something like this in there:
>> usb 2-1.5: New USB device found, idVendor=12cf, idProduct=7111
>
> Not exactly what I get. I get:
>
> [ 6.940474] generic-usb 0003:12CF:7111.0001: hiddev0,hidraw0: USB HID v1.11 Device [Axentia Technologies AB ALERT FM Radio] on usb-0000:00:1a.1-1/input2
> [ 6.940494] usbcore: registered new interface driver usbhid
> [ 6.940496] usbhid: USB HID core driver
>
>
>> Note the 2-1.5
>> 3) "cd /sys/bus/usb/drivers/usbhid"
>> 4) "ls"
>> You should see a symlink in there starting with the same prefix as in the
>> dmesg, followed by :1.2, ie: "2-1.5:1.2",
>
> Ok, I see:
>
> 9-4.1:1.0
> 9-4.4:1.0
> 4-1:1.2 <- second time around I see this!
>
> Which I can't correlate to any of the dmesg output. They link to:
>
> ../../../../devices/pci0000:00/0000:00:02.0/0000:0e:00.0/usb9/9-4/9-4.1/9-4.1:1.0
> ../../../../devices/pci0000:00/0000:00:02.0/0000:0e:00.0/usb9/9-4/9-4.4/9-4.4:1.0
>
> And appear to be the mouse and keyboard.
>
>> then do:
>> 5) "echo '2-1.5:1.2' > unbind"
>> Replacing 2-1.5:1.2 with the address string for your device
>
> Just for kicks, I went ahead and unbound the two devices.
>
>> 6) "modprobe radio-usb-si470x"
>> 7) "cd /sys/bus/usb/drivers/radio-si470x"
>> 8) "echo '0x12cf 0x7111' > new_id"
>> 9) ls, now the 2-1.5:1.2 like string should be there, if not
>> see "dmesg" for errors :|
>
> Well, I now see 4-1:1.2 -> ../../../../devices/pci0000:00/0000:00:1a.1/usb4/4-1/4-1:1.2
>
>> 10) "ls /dev/radio*"
>> If there is a radio device there things seem to be working!
>
> And I now see /dev/radio0
>
>>
>> Now start a program recording / looping back sound from
>> the alsa device for the usb-stick, and then start a radio
>> tuning program, for example the very simple "radio" app
>> from xawtv.
>
> "radio" appears to get a little further along. It actual seems to enable the radio in so much as when it is running, I get what seems like real radio static as to the just near silence I get otherwise. But I don't get any change in the output no matter the frequency tuned.
>

Ok, good, looking in:
drivers/media/radio/si470x/radio-si470x-common.c

I see the following module parameters:
/* Spacing (kHz) */
/* 0: 200 kHz (USA, Australia) */
/* 1: 100 kHz (Europe, Japan) */
/* 2:  50 kHz */
static unsigned short space = 2;
module_param(space, ushort, 0444);
MODULE_PARM_DESC(space, "Spacing: 0=200kHz 1=100kHz *2=50kHz*");

/* Bottom of Band (MHz) */
/* 0: 87.5 - 108 MHz (USA, Europe)*/
/* 1: 76   - 108 MHz (Japan wide band) */
/* 2: 76   -  90 MHz (Japan) */
static unsigned short band = 1;
module_param(band, ushort, 0444);
MODULE_PARM_DESC(band, "Band: 0=87.5..108MHz *1=76..108MHz* 2=76..90MHz");

/* De-emphasis */
/* 0: 75 us (USA) */
/* 1: 50 us (Europe, Australia, Japan) */
static unsigned short de = 1;
module_param(de, ushort, 0444);
MODULE_PARM_DESC(de, "De-emphasis: 0=75us *1=50us*");

/* Tune timeout */
static unsigned int tune_timeout = 3000;
module_param(tune_timeout, uint, 0644);
MODULE_PARM_DESC(tune_timeout, "Tune timeout: *3000*");

/* Seek timeout */
static unsigned int seek_timeout = 5000;
module_param(seek_timeout, uint, 0644);
MODULE_PARM_DESC(seek_timeout, "Seek timeout: *5000*");

Especially the band parameter looks interesting, as
according to your commented usb dumps your device has a
bottom of 87.5 Mhz, were the driver defaults to 76 Mhz,
so if you tuned to a known to work station in radio,
you actually didn't because of this setting being wrong,
edit /etc/modprobe.d/radio.conf

And put the following there:
options radio-usb-si470x band=0

Then do:
rmmod radio-usb-si470x
modprobe radio-usb-si470x

And redo the driver binding, now tune to a radio station
you know to work (from testing in windows for example)
using radio, and hopefully things will work then.

>>
>> ###
>>
>> If the above does not work, it looks like you do need to write
>> some software to drive the device yourself after all. IMHO the end
>> result of this project would be to write a v4l2 kernel driver.
>
> No problem. I'm happy to do what I can.
>
>>
>> For starters we can write a little libusb program, but once we've
>> put in that effort why not go all the way and make it usable as a
>> normal/standard radio device under Linux?
>>
>> The first step would be to catch some USB-traces of windows setting
>> the frequency, or iow windows doing some tuning to a radio station.
>
> I have some of that, and maybe this will tell you at a glance if it should be compatible.

I'm not that familiar with the si470x driver, lets first give the above a try
before we dive into the USB dumps. A quick look at the si470x driver does show
that it is doing various sanity check though, so if your device is not an
actual si470x, it is very close.

Regards,

Hans

Re: Controlling and reading a usb radio

[Deron <de...@pa...>]

On 5/12/12 10:57 PM, Hans de Goede wrote:
>
>> "radio" appears to get a little further along. It actual seems to 
>> enable the radio in so much as when it is running, I get what seems 
>> like real radio static as to the just near silence I get otherwise. 
>> But I don't get any change in the output no matter the frequency tuned.
>>
>
>
> Ok, good, looking in:
> drivers/media/radio/si470x/radio-si470x-common.c
>
> I see the following module parameters:
> /* Spacing (kHz) */
> /* 0: 200 kHz (USA, Australia) */
> /* 1: 100 kHz (Europe, Japan) */
> /* 2:  50 kHz */
> static unsigned short space = 2;
> module_param(space, ushort, 0444);
> MODULE_PARM_DESC(space, "Spacing: 0=200kHz 1=100kHz *2=50kHz*");
>
> /* Bottom of Band (MHz) */
> /* 0: 87.5 - 108 MHz (USA, Europe)*/
> /* 1: 76   - 108 MHz (Japan wide band) */
> /* 2: 76   -  90 MHz (Japan) */
> static unsigned short band = 1;
> module_param(band, ushort, 0444);
> MODULE_PARM_DESC(band, "Band: 0=87.5..108MHz *1=76..108MHz* 
> 2=76..90MHz");
>
> /* De-emphasis */
> /* 0: 75 us (USA) */
> /* 1: 50 us (Europe, Australia, Japan) */
> static unsigned short de = 1;
> module_param(de, ushort, 0444);
> MODULE_PARM_DESC(de, "De-emphasis: 0=75us *1=50us*");
>
> /* Tune timeout */
> static unsigned int tune_timeout = 3000;
> module_param(tune_timeout, uint, 0644);
> MODULE_PARM_DESC(tune_timeout, "Tune timeout: *3000*");
>
> /* Seek timeout */
> static unsigned int seek_timeout = 5000;
> module_param(seek_timeout, uint, 0644);
> MODULE_PARM_DESC(seek_timeout, "Seek timeout: *5000*");
>
> Especially the band parameter looks interesting, as
> according to your commented usb dumps your device has a
> bottom of 87.5 Mhz, were the driver defaults to 76 Mhz,
> so if you tuned to a known to work station in radio,
> you actually didn't because of this setting being wrong,
> edit /etc/modprobe.d/radio.conf
>
> And put the following there:
> options radio-usb-si470x band=0
>
> Then do:
> rmmod radio-usb-si470x
> modprobe radio-usb-si470x
>
> And redo the driver binding, now tune to a radio station
> you know to work (from testing in windows for example)
> using radio, and hopefully things will work then.
>


I was so hopeful! However, it made no difference. I even then tried 
setting space=0 and de=0, to no avail.

My attempts at a custom frequency changing program will generate pops in 
the audio output when changing the frequency, but the audio is silent. 
The radio program 
(http://www.cs.fsu.edu/~baker/devices/lxr/http/source/xawtv-3.95/console/radio.c) 
seems to enable the radio as when it is started the audio goes from 
silent to static, but I get the error "VIDIOCGAUDIO: Invalid argument" 
twice to console and changing the frequency does not generate any change 
in audio output. No pop, no change to static.


Thanks!

Deron

Re: Controlling and reading a usb radio

[Chuck C. <cm...@ea...>]

The chip that is being controlled is by SIlicaon labs
http://www.silabs.com/pages/Silabs-Search.aspx?q=si470x

On 05/13/2012 12:01 PM, Deron wrote:
> On 5/12/12 10:57 PM, Hans de Goede wrote:
>>> "radio" appears to get a little further along. It actual seems to
>>> enable the radio in so much as when it is running, I get what seems
>>> like real radio static as to the just near silence I get otherwise.
>>> But I don't get any change in the output no matter the frequency tuned.
>>>
>>
>> Ok, good, looking in:
>> drivers/media/radio/si470x/radio-si470x-common.c
>>
>> I see the following module parameters:
>> /* Spacing (kHz) */
>> /* 0: 200 kHz (USA, Australia) */
>> /* 1: 100 kHz (Europe, Japan) */
>> /* 2:  50 kHz */
>> static unsigned short space = 2;
>> module_param(space, ushort, 0444);
>> MODULE_PARM_DESC(space, "Spacing: 0=200kHz 1=100kHz *2=50kHz*");
>>
>> /* Bottom of Band (MHz) */
>> /* 0: 87.5 - 108 MHz (USA, Europe)*/
>> /* 1: 76   - 108 MHz (Japan wide band) */
>> /* 2: 76   -  90 MHz (Japan) */
>> static unsigned short band = 1;
>> module_param(band, ushort, 0444);
>> MODULE_PARM_DESC(band, "Band: 0=87.5..108MHz *1=76..108MHz*
>> 2=76..90MHz");
>>
>> /* De-emphasis */
>> /* 0: 75 us (USA) */
>> /* 1: 50 us (Europe, Australia, Japan) */
>> static unsigned short de = 1;
>> module_param(de, ushort, 0444);
>> MODULE_PARM_DESC(de, "De-emphasis: 0=75us *1=50us*");
>>
>> /* Tune timeout */
>> static unsigned int tune_timeout = 3000;
>> module_param(tune_timeout, uint, 0644);
>> MODULE_PARM_DESC(tune_timeout, "Tune timeout: *3000*");
>>
>> /* Seek timeout */
>> static unsigned int seek_timeout = 5000;
>> module_param(seek_timeout, uint, 0644);
>> MODULE_PARM_DESC(seek_timeout, "Seek timeout: *5000*");
>>
>> Especially the band parameter looks interesting, as
>> according to your commented usb dumps your device has a
>> bottom of 87.5 Mhz, were the driver defaults to 76 Mhz,
>> so if you tuned to a known to work station in radio,
>> you actually didn't because of this setting being wrong,
>> edit /etc/modprobe.d/radio.conf
>>
>> And put the following there:
>> options radio-usb-si470x band=0
>>
>> Then do:
>> rmmod radio-usb-si470x
>> modprobe radio-usb-si470x
>>
>> And redo the driver binding, now tune to a radio station
>> you know to work (from testing in windows for example)
>> using radio, and hopefully things will work then.
>>
>
> I was so hopeful! However, it made no difference. I even then tried
> setting space=0 and de=0, to no avail.
>
> My attempts at a custom frequency changing program will generate pops in
> the audio output when changing the frequency, but the audio is silent.
> The radio program
> (http://www.cs.fsu.edu/~baker/devices/lxr/http/source/xawtv-3.95/console/radio.c)
> seems to enable the radio as when it is started the audio goes from
> silent to static, but I get the error "VIDIOCGAUDIO: Invalid argument"
> twice to console and changing the frequency does not generate any change
> in audio output. No pop, no change to static.
>
>
> Thanks!
>
> Deron
>
>
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
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> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
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>

Re: Controlling and reading a usb radio

[Hans de G. <hde...@re...>]

Hi,

On 05/13/2012 06:01 PM, Deron wrote:
> On 5/12/12 10:57 PM, Hans de Goede wrote:
>>
>>> "radio" appears to get a little further along. It actual seems to enable the radio in so much as when it is running, I get what seems like real radio static as to the just near silence I get otherwise. But I don't get any change in the output no matter the frequency tuned.
>>>
>>
>>
>> Ok, good, looking in:
>> drivers/media/radio/si470x/radio-si470x-common.c
>>
>> I see the following module parameters:
>> /* Spacing (kHz) */
>> /* 0: 200 kHz (USA, Australia) */
>> /* 1: 100 kHz (Europe, Japan) */
>> /* 2: 50 kHz */
>> static unsigned short space = 2;
>> module_param(space, ushort, 0444);
>> MODULE_PARM_DESC(space, "Spacing: 0=200kHz 1=100kHz *2=50kHz*");
>>
>> /* Bottom of Band (MHz) */
>> /* 0: 87.5 - 108 MHz (USA, Europe)*/
>> /* 1: 76 - 108 MHz (Japan wide band) */
>> /* 2: 76 - 90 MHz (Japan) */
>> static unsigned short band = 1;
>> module_param(band, ushort, 0444);
>> MODULE_PARM_DESC(band, "Band: 0=87.5..108MHz *1=76..108MHz* 2=76..90MHz");
>>
>> /* De-emphasis */
>> /* 0: 75 us (USA) */
>> /* 1: 50 us (Europe, Australia, Japan) */
>> static unsigned short de = 1;
>> module_param(de, ushort, 0444);
>> MODULE_PARM_DESC(de, "De-emphasis: 0=75us *1=50us*");
>>
>> /* Tune timeout */
>> static unsigned int tune_timeout = 3000;
>> module_param(tune_timeout, uint, 0644);
>> MODULE_PARM_DESC(tune_timeout, "Tune timeout: *3000*");
>>
>> /* Seek timeout */
>> static unsigned int seek_timeout = 5000;
>> module_param(seek_timeout, uint, 0644);
>> MODULE_PARM_DESC(seek_timeout, "Seek timeout: *5000*");
>>
>> Especially the band parameter looks interesting, as
>> according to your commented usb dumps your device has a
>> bottom of 87.5 Mhz, were the driver defaults to 76 Mhz,
>> so if you tuned to a known to work station in radio,
>> you actually didn't because of this setting being wrong,
>> edit /etc/modprobe.d/radio.conf
>>
>> And put the following there:
>> options radio-usb-si470x band=0
>>
>> Then do:
>> rmmod radio-usb-si470x
>> modprobe radio-usb-si470x
>>
>> And redo the driver binding, now tune to a radio station
>> you know to work (from testing in windows for example)
>> using radio, and hopefully things will work then.
>>
>
>
> I was so hopeful! However, it made no difference. I even then tried setting space=0 and de=0, to no avail.
>
> My attempts at a custom frequency changing program will generate pops in the audio output when changing the frequency, but the audio is silent. The radio program (http://www.cs.fsu.edu/~baker/devices/lxr/http/source/xawtv-3.95/console/radio.c) seems to enable the radio as when it is started the audio goes from silent to static, but I get the error "VIDIOCGAUDIO: Invalid argument" twice to console and changing the frequency does not generate any change in audio output. No pop, no change to static.

Ah, you're using an old version of xawtv which uses the no longer
supported v4l1 API, there is a newer version here, hopefully its
radio.c version will work better:
http://git.linuxtv.org/xawtv3.git

Regards,

Hans

Re: Controlling and reading a usb radio

[Deron <de...@pa...>]

>> My attempts at a custom frequency changing program will generate pops 
>> in the audio output when changing the frequency, but the audio is 
>> silent. The radio program 
>> (http://www.cs.fsu.edu/~baker/devices/lxr/http/source/xawtv-3.95/console/radio.c) 
>> seems to enable the radio as when it is started the audio goes from 
>> silent to static, but I get the error "VIDIOCGAUDIO: Invalid 
>> argument" twice to console and changing the frequency does not 
>> generate any change in audio output. No pop, no change to static.
>
> Ah, you're using an old version of xawtv which uses the no longer
> supported v4l1 API, there is a newer version here, hopefully its
> radio.c version will work better:
> http://git.linuxtv.org/xawtv3.git
>
> Regards,
>
> Hans
>

I just used the URL as reference thinking it was the latest. I actually 
installed the program with apt-get install radio as I recall, and it 
seems to be old as well. Compiling the latest requires X11 which is a 
bit crazy for a server. I'm going to strip out the frequency change 
commands and see if I can get it to work...


.........

IT WORKS!!!

With the following (roughly) commands, I can make it work:

nano /etc/modprobe.d/radio.conf
add: options radio-usb-si470x space=0 band=0 de=0

cd /sys/bus/usb/drivers/usbhid
echo '4-1:1.2' > unbind
modprobe radio-usb-si470x
cd /sys/bus/usb/drivers/radio-si470x
echo '0x12cf 0x7111' > new_id

/dev/radio0 now exists and responds to proper commands. I can record 
with arecord -D "plughw:CARD=Radio,DEV=0" -f cd >audio.raw


So what can I do to make this permanent so as to survive resets of the 
server?

Can I do anything to help get this added to future releases?

And Hans, I owe you an AlertFM device :-) Would it be of any use to you? 
The device also supports some new US EAS like system, but it is not in 
my area (yet?) so no idea what would be required to make that work. Just 
happy to have the radio working properly now!

Deron

Re: Controlling and reading a usb radio

[Hans de G. <hde...@re...>]

Hi,

On 05/14/2012 11:45 PM, Deron wrote:
>
>>> My attempts at a custom frequency changing program will generate pops in the audio output when changing the frequency, but the audio is silent. The radio program (http://www.cs.fsu.edu/~baker/devices/lxr/http/source/xawtv-3.95/console/radio.c) seems to enable the radio as when it is started the audio goes from silent to static, but I get the error "VIDIOCGAUDIO: Invalid argument" twice to console and changing the frequency does not generate any change in audio output. No pop, no change to static.
>>
>> Ah, you're using an old version of xawtv which uses the no longer
>> supported v4l1 API, there is a newer version here, hopefully its
>> radio.c version will work better:
>> http://git.linuxtv.org/xawtv3.git
>>
>> Regards,
>>
>> Hans
>>
>
> I just used the URL as reference thinking it was the latest. I actually installed the program with apt-get install radio as I recall, and it seems to be old as well. Compiling the latest requires X11 which is a bit crazy for a server. I'm going to strip out the frequency change commands and see if I can get it to work...
>
>
> .........
>
> IT WORKS!!!

Good!

>
> With the following (roughly) commands, I can make it work:
>
> nano /etc/modprobe.d/radio.conf
> add: options radio-usb-si470x space=0 band=0 de=0
>
> cd /sys/bus/usb/drivers/usbhid
> echo '4-1:1.2' > unbind
> modprobe radio-usb-si470x
> cd /sys/bus/usb/drivers/radio-si470x
> echo '0x12cf 0x7111' > new_id
>
> /dev/radio0 now exists and responds to proper commands. I can record with arecord -D "plughw:CARD=Radio,DEV=0" -f cd >audio.raw
>
>
> So what can I do to make this permanent so as to survive resets of the server?

I've attached a kernel patch, if you build a kernel with this patch you should no
longer need the unbind and new_id magic.

> Can I do anything to help get this added to future releases?

Test the patch.

> And Hans, I owe you an AlertFM device :-) Would it be of any use to you?

I appreciate the offer, but I already have bought an si470x based usb radio
stick myself, it should arrive at my home soon-ish. The reason I bought one
is because of the poor state of userspace support for radio devices under
Linux, which I hope to one day improve...

What would be great (if you think it would be fun to do) would be if you
could work on a decent userspace app for radios. IE something like
gnome-radio ported to gnome/gtk3 and taught that most modern radio's
don't have analog output, but that it needs to read the data from
an alsa device and loopback it into another alsa device.

For the alsa loopback part, see the code in the tv part of xawtv which
already knows how to figure out which alsa node belongs to a v4l2 node,
and how to loop back. Another project would be separating that code
from the tv part of xawtv and also make the xawtv radio app use it :)

If you want to donate me some hardware, I'm always looking for *old*
usb webcams to complete my collection (which I've for testing purposes
as I maintain a lot of usb webcam drivers). Chances are that whatever
you've I already have, so if you've an old cam you consider donating,
please first plug it in and do an lsusb, no use in shipping me a cam I
already have, and I already have about a 100 different models :)

Regards,

Hans

Re: Controlling and reading a usb radio

[Deron <de...@pa...>]

On 5/8/12 3:55 AM, Hans de Goede wrote:
> Hi,
>
> On 05/07/2012 05:10 PM, Deron wrote:
>> Hello,
>>
>> I hope this is an appropriate things to post here. I have an AlertFM usb
>> radio that is "windows only" that I want to use on my Ubuntu server. The
>> plan is to set it up to listen for EAS warnings on our local radio
>> station. (We live a long way from civilization and don't always have the
>> TV on). If I can get the audio stream, I can do the rest easy enough
>> (I've got that part written and tested using recordings of EAS audio
>> messages).
>>
>> Anyway, I have a windows computer and captured some channel changing
>> data using their software, and digging around I found this software
>> which actually recommends hidapi for HID devices. No problem, I have
>> that installed along with libusb and I think I even have it changing
>> channels (one report sets the channel, and another reads back the
>> current channel. Still an input report I can't seem to grab which gives
>> signal strength data etc, but I could live without that.)
>>
>> What I don't have now is the audio stream. I'm not very familiar with
>> USB, so this is a really basic question, but what do I do to read that
>> data? I'm guessing that hidapi won't be able to read that data, and
>> somehow need to mix in calls with libusb? I've not had much luck finding
>> sample applications for hidapi, and if someone could just nudge me in
>> the correct direction I would appreciate it or even basic info on USB
>> that would fluff out my knowledge without have to read an encyclopedia
>> on USB.
>
> I see that you've already gotten several useful replies further in the
> thread. So it looks like getting the audio from the device is a solved
> problem, which only leaves the tuning. Tuning normally is handled
> by v4l2 kernel driver.

I'm not so sure. Using the ALSA command:

arecord -l

shows:

card 0: Intel [HDA Intel], device 0: ALC889 Analog [ALC889 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: ALC889 Digital [ALC889 Digital]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 2: ALC889 Analog [ALC889 Analog]
   Subdevices: 2/2
   Subdevice #0: subdevice #0
   Subdevice #1: subdevice #1
card 1: Radio [ALERT FM Radio], device 0: USB Audio [USB Audio]
   Subdevices: 1/1
   Subdevice #0: subdevice #0

But

arecord -D "plughw:CARD=Radio" -f cd >audio.raw

Give me static. Ok, but a simple little program using hidapi appears to 
set the freq, but all I get are "clicks" in the arecord output that 
conincide with the attempts to change the frequency. I even tried 
looping through all frequencies every ten seconds but no go.

>
> Chances are that your device is using the si470x chipset, as that uses
> a usb-audio class interface for the audio and a hid interface for
> tuning...

I took it apart awhile ago, and it is using an si part, but I don't 
recall that being the number. I'll have to find my notes...

Ok, best as I can see here are the number from the si chip is:

silabs
f321
ecnab3
o741+

> To test this you would need to do the following (as root):
>
> 1) plug in the device
> 2) do dmesg, you should see something like this in there:
> usb 2-1.5: New USB device found, idVendor=12cf, idProduct=7111

Not exactly what I get. I get:

[    6.940474] generic-usb 0003:12CF:7111.0001: hiddev0,hidraw0: USB HID 
v1.11 Device [Axentia Technologies AB ALERT FM Radio] on 
usb-0000:00:1a.1-1/input2
[    6.940494] usbcore: registered new interface driver usbhid
[    6.940496] usbhid: USB HID core driver


> Note the 2-1.5
> 3) "cd /sys/bus/usb/drivers/usbhid"
> 4) "ls"
> You should see a symlink in there starting with the same prefix as in the
> dmesg, followed by :1.2, ie: "2-1.5:1.2",

Ok, I see:

9-4.1:1.0
9-4.4:1.0
4-1:1.2 <- second time around I see this!

Which I can't correlate to any of the dmesg output. They link to:

../../../../devices/pci0000:00/0000:00:02.0/0000:0e:00.0/usb9/9-4/9-4.1/9-4.1:1.0
../../../../devices/pci0000:00/0000:00:02.0/0000:0e:00.0/usb9/9-4/9-4.4/9-4.4:1.0

And appear to be the mouse and keyboard.

> then do:
> 5) "echo '2-1.5:1.2' > unbind"
> Replacing 2-1.5:1.2 with the address string for your device

Just for kicks, I went ahead and unbound the two devices.

> 6) "modprobe radio-usb-si470x"
> 7) "cd /sys/bus/usb/drivers/radio-si470x"
> 8) "echo '0x12cf 0x7111' > new_id"
> 9) ls, now the 2-1.5:1.2 like string should be there, if not
>    see "dmesg" for errors :|

Well, I now see 4-1:1.2 -> 
../../../../devices/pci0000:00/0000:00:1a.1/usb4/4-1/4-1:1.2

> 10) "ls /dev/radio*"
> If there is a radio device there things seem to be working!

And I now see /dev/radio0

>
> Now start a program recording / looping back sound from
> the alsa device for the usb-stick, and then start a radio
> tuning program, for example the very simple "radio" app
> from xawtv.

"radio" appears to get a little further along. It actual seems to enable 
the radio in so much as when it is running, I get what seems like real 
radio static as to the just near silence I get otherwise. But I don't 
get any change in the output no matter the frequency tuned.

>
> ###
>
> If the above does not work, it looks like you do need to write
> some software to drive the device yourself after all. IMHO the end
> result of this project would be to write a v4l2 kernel driver.

No problem. I'm happy to do what I can.

>
> For starters we can write a little libusb program, but once we've
> put in that effort why not go all the way and make it usable as a
> normal/standard radio device under Linux?
>
> The first step would be to catch some USB-traces of windows setting
> the frequency, or iow windows doing some tuning to a radio station.

I have some of that, and maybe this will tell you at a glance if it 
should be compatible. Here is the output from a Windows program. It was 
something like USBalizer or some such. I cut out the repeating parts 
(the "input report"). Frequency was 107.7 when I started the capture, 
and then 107.7 -> 107.9 -> 87.5 -> 87.7.


Input Report id:18 len:13            12 02 05 FC  65 41 A5 3E  10 3E 9F 
3C 08     repeating


Set Report (Feature id:4 len:3)        04 80 66                        
             setting freq to 107.9
Get Report (Feature id:11 len:64)    0B 02 05                            
         x9
Get Report (Feature id:11 len:64)    0B 02 01                            
         x17
Input Report id:18 len:13            12 02 05 FC 65 41 A5 3E 10 3E 9F 3C 
08        x1
                                          (3rd element corrisponds to 
RSSI in the Windows AlertFM interface)    (5th element appears to 
corrispond to BER in the Windows AlertFM interface)

Get Report (Feature id:11 len:64)    0B 02 01                            
         x22
Get Report (Feature id:11 len:64)    0B 42 06                            
         x1
Set Report (Feature id:4 len:3)        04 00 66
Get Report (Feature id:12 len:64)    0C FC 66                            
         x1


Input Report id:18 len:13            12 02 04 FC 66 41 A5 3E 10 3E 9F 3C 
08        repeating
Input Report id:18 len:13            12 02 05 FC 66 41 A5 3E 10 3E 9F 3C 
08        repeating


Set Report (Feature id:4 len:3)        04 80 00                        
             setting freq to 87.5 (it appears that the value they use is 
(freq - 87.5) * 5 )
Get Report (Feature id:11 len:64)    0B 02 04                            
         x
Input Report id:18 len:13            12 02 04 FC 66 41 A5 3E 10 3E 9F 3C 08
Get Report (Feature id:11 len:64)    0B 02 14
Input Report id:18 len:13            12 02 14 FC 00 41 A5 3E 10 3E 9F 3C 08
Get Report (Feature id:11 len:64)    0B 02 14
Set Report (Feature id:4 len:3)        04 00 00
Get Report (Feature id:12 len:64)    0C FC 00


Input Report id:18 len:13            12 02 15 FC 00 41 A5 3E 10 3E 9F 3C 08
Input Report id:18 len:13            12 02 13 FC 00 41 A5 3E 10 3E 9F 3C 08

Feature Report
     02 0a 50
waiting...
Data read:
     12 14 18 f8 00 42 3f d6 0c c7 c2 85 d9

Set Report (Feature id:4 len:3)        04 80 01                        
             setting freq to 87.7
Get Report (Feature id:11 len:64)    0B 02 14
Get Report (Feature id:11 len:64)    0B 02 11
Input Report id:18 len:13            12 02 14 FC 00 41 A5 3E 10 3E 9F 3C 08
Get Report (Feature id:11 len:64)    0B 02 11
Set Report (Feature id:4 len:3)        04 00 01
Get Report (Feature id:12 len:64)    0C FC 01

Input Report id:18 len:13            12 02 11 FC 01 41 A5 3E 10 3E 9F 3C 08
Input Report id:18 len:13            12 12 10 FC 01 41 A5 3E 10 3E 9F 3C 08


I did not capture from the beginning to the end of startup etc. I can go 
back and do that if helpful and post uncut results to a page somewhere 
on one of my web sites.

Thanks for your great email!

Deron

>
> The way to do that now a days is to start windows inside a vm under Linux
> and then redirect the usb device to the windows vm.
>
> When you've the device working inside a windows vm, then:
> -figure out on which usb bus the device sits (lsusb will tell you this)
> -shutdown the windows vm
> -unplug the device
> -start wireshark as root and ignore the security warning, it is not 
> really
>  relevant when using wireshark to monitor usb devices
> -tell wireshark to record usb transfers on the bus the device was on
> -re-plug in the device, this needs to happen after starting wireshark,
>  so that wireshark sees the usb device descriptors come past and can
>  thus automatically load the right protocol dissectors
> -write down where in the log wireshark now is, as everything up till this
>  point was send by the standard linux hid and audio drivers
> -start the vm and redirect the device to it
> -write down where in the log wireshark now is, as everything up till this
>  was windows initialization which is likely not interesting
> -start the windows radio app, look in the wireshrak log for any HID 
> messages,
>  these are likely doing the tuning
> -tune to a certain frequency if possible (ie no auto tuning, but pick 
> a fixed freq.),
>  write down where in the log you are, and what frequency you tuned to
> -tune to a another frequency if possible (ie no auto tuning, but pick 
> a fixed freq.)
>  write down where in the log you are, and what frequency you tuned to
> -stop the windows radio app
> -stop wireshark capturing usb packets
> -save the capture in wireshark!
>
> And then you can go and try to figure things out from the capture. 
> Note besides
> a libusb developer I'm also a v4l2 developer and have reverse 
> engineered quite
> a few usb devices. This sounds like a fun little project and I would 
> like to help,
> which requires me getting my hands on such a device...
>
> Regards,
>
> Hans
>

Re: Controlling and reading a usb radio

[Vincent P. <plr...@gm...>]

Le dimanche 13 mai 2012 06:29:44, Deron a écrit :
> But
> 
> arecord -D "plughw:CARD=Radio" -f cd >audio.raw
> 
> Give me static. Ok, but a simple little program using hidapi appears to
> set the freq, but all I get are "clicks" in the arecord output that
> conincide with the attempts to change the frequency. I even tried
> looping through all frequencies every ten seconds but no go.

FWIW, I have a similar experience with a radio part on a PCI tv card. When I 
enable FM tuner and loop the card's audio dev to speakers, I get static-ish 
noise... Until I switch the FM off, at which point I get perfect audio until 
some buffer runs out of data (ie, half a second, by hear).
I suspect there is a bug in some ring buffer access, where writing would 
overwrite not-read-yet data, or where updating write pointer would interfere 
with read pointer. But I'm not sure where to look.

-- 
Vincent Pelletier

Re: Controlling and reading a usb radio

[Vincent P. <plr...@gm...>]

Le dimanche 13 mai 2012 11:17:16, Vincent Pelletier a écrit :
> Le dimanche 13 mai 2012 06:29:44, Deron a écrit :
> > But
> > 
> > arecord -D "plughw:CARD=Radio" -f cd >audio.raw
> > 
> > Give me static. Ok, but a simple little program using hidapi appears to
> > set the freq, but all I get are "clicks" in the arecord output that
> > conincide with the attempts to change the frequency. I even tried
> > looping through all frequencies every ten seconds but no go.
> 
> FWIW, I have a similar experience with a radio part on a PCI tv card. When
> I enable FM tuner and loop the card's audio dev to speakers, I get
> static-ish noise... Until I switch the FM off, at which point I get
> perfect audio until some buffer runs out of data (ie, half a second, by
> hear).
> I suspect there is a bug in some ring buffer access, where writing would
> overwrite not-read-yet data, or where updating write pointer would
> interfere with read pointer. But I'm not sure where to look.

And I was wrong.
The solution to this problem is to use "fm -T forever on" so "fm" keeps the 
device opened - otherwise, tuner is put to sleep but sound is not muted, 
resulting in static noise.

-- 
Vincent Pelletier