[Freeswitch-users] SIM7100 LTE modem with USB audio

Wed Jul 26 22:41:39 UTC 2017

I looked inside gsmopen_protocol.cpp and my eyes hurt. It has so many
hardcoded vendor-specific commands, and it does not know the actual
vendor that it speaks to. I really don't like adding more bad code
here.

I'm inclining to have a Perl daemon working the AT commands via the
control UART ports, and telling FreeSWITCH take the audio channel from
the audio UART port when it's ready. I think mod_portaudio should do
the job after minor modifications.

Then the AT command handler can be written in a modern and modular
fashion, with independent modules for different hardware.

Also this way we would open the door for new hardware solutions which
are able to send/receive PCM via ttyUSB ports. Then, for example, one
may build a hardware phone with it :)

On Wed, Jul 26, 2017 at 1:54 AM, Stanislav Sinyagin <ssinyagin at gmail.com> wrote:
> I assembled the lab, and will start digging the code tomorrow.
>
> The modem sends PCM audio via an UART USB device, just like Huawei dongles
> do. So, it looks like only a matter of accommodating to vendor and product
> codes and initialization strings.
>
>
>
> On 25 Jul 2017 15:10, "Giovanni Maruzzelli" <gmaruzz at gmail.com> wrote:
>>
>>
>>
>> On 23 July 2017 at 10:17, Stanislav Sinyagin <ssinyagin at gmail.com> wrote:
>>>
>>> Hi Giovanni, I only had time to configure it for Internet access:
>>>
>>> https://txlab.wordpress.com/2017/07/23/simcom-sim7100e-lte-modem/
>>>
>>> The benefit is mPCIe interface, so it can be placed inside and enclosure.
>>> No silly dongles any more :)
>>>
>>> I'll tinker with voice some time later. I can also provide you SSH access
>>> if you wish to work on gsmopen update.
>>
>>
>> Please, let me know if any progress or so.
>>
>> Will not be so easy to interface audio to it via USB, will need to create
>> a kernel driver, or use a userspace USB lib and create a user space driver.
>>
>> Happy hacking!
>>
>> -giovanni
>>
>>
>>
>>>
>>>
>>>
>>>
>>> On 21 Jul 2017 18:36, "Giovanni Maruzzelli" <gmaruzz at gmail.com> wrote:
>>>>
>>>> Hello Stanislav,
>>>>
>>>> have you had time to tinker with it?
>>>>
>>>> How it goes?
>>>>
>>>> Also, why you would prefer this one instead of the already supported
>>>> ones?
>>>>
>>>> -giovanni
>>>>
>>>>
>>>> On 8 July 2017 at 21:28, Stanislav Sinyagin <ssinyagin at gmail.com> wrote:
>>>>>
>>>>> Simcom has recently released a new 4G/LTE modem, and it has USB audio
>>>>> support.
>>>>> You can find sim7100_usb_audio_application_note_v0.01.pdf   with
>>>>> details at the vendor site, or at techship.com  after registration.
>>>>>
>>>>> It transmits 8kHZ, 16-bit PCM audio via a USB UART simulation.
>>>>>
>>>>> So, in theory, gsmopen module may be adapted to it (or maybe a new
>>>>> module is worth starting).
>>>>>
>>>>> I ordered a sample, will check it out soon.
>>>>>
>>>>> cheers,
>>>>> stanislav
>>>>>
>>>>>
>>>>> _________________________________________________________________________
>>>>> Professional FreeSWITCH Consulting Services:
>>>>> consulting at freeswitch.org
>>>>> http://www.freeswitchsolutions.com
>>>>>
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>>>>>
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>>>>>
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>>>>
>>>>
>>>>
>>>>
>>>> --
>>>>
>>>> Sincerely,
>>>>
>>>> Giovanni Maruzzelli
>>>> OpenTelecom.IT
>>>> cell: +39 347 266 56 18
>>>>
>>>>
>>>> _________________________________________________________________________
>>>> Professional FreeSWITCH Consulting Services:
>>>> consulting at freeswitch.org
>>>> http://www.freeswitchsolutions.com
>>>>
>>>> Official FreeSWITCH Sites
>>>> http://www.freeswitch.org
>>>> http://confluence.freeswitch.org
>>>> http://www.cluecon.com
>>>>
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>>>
>>>
>>> _________________________________________________________________________
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>>> http://www.freeswitchsolutions.com
>>>
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>>>
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>>
>>
>>
>>
>> --
>>
>> Sincerely,
>>
>> Giovanni Maruzzelli
>> OpenTelecom.IT
>> cell: +39 347 266 56 18
>>
>> _________________________________________________________________________
>> Professional FreeSWITCH Consulting Services:
>> consulting at freeswitch.org
>> http://www.freeswitchsolutions.com
>>
>> Official FreeSWITCH Sites
>> http://www.freeswitch.org
>> http://confluence.freeswitch.org
>> http://www.cluecon.com
>>
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