Hi,
The product is fine,I have been using the SIM900D without any problems in many
different countries as well. It may run for a days without dropping the
connection. Obviously you have a hardware issue as your not supplying enough
voltage or power supply voltage drops when the gsm signal is l
Hi chrysn,
On Fri, Nov 14, 2014 at 05:43:47PM +0100, chrysn wrote:
>
> i was afraid so when i first saw them, but i never ran into an
> UNDER-VOLTAGE POWER DOWN condition so far; thing is, i'm running my
> entire board off 3.3V, which is the threshold for the warning. the
> module can do down to
Hi chrysn,
On Fri, Nov 14, 2014 at 02:12:16PM +0100, chrysn wrote:
>
> (i'd be very careful with that kind of oob mechanisms from a
> synchronization point of view, but then again, i'd much rather have a
> modem on a clean spi interface with cs and interrupt than all that
> asynchronous serial s
Chrysn,
yes, Simcom tech department sucks... they've had some internal issues on
the move from SIM340 to SIM900.
They are chinese and english docs are poor and mostly non-existent.
We've had a tech contact long ago but hopefully I haven't contacted them
for years.
Regarding the hw, you are too clos
hello sergio,
thank you for your responses.
On Fri, Nov 14, 2014 at 10:06:00AM -0300, Sergio R. Caprile wrote:
> Since PPP expects a serial transparent interface, and you are not
> providing that, I would write a "tap" which provides that to PPP and
> "taps" all other data out.
>
> GSM modem ---
hello sylvain,
thank you for your quick reply.
On Fri, Nov 14, 2014 at 11:54:45AM +0100, Sylvain Rochet wrote:
> I feel dazed and confused, is this really a thing which is actually
> usual in the wild or is it specific to your modem ?
i've seen it at least in different simcom devices (the volta
BTW,
"\r\nUNDER-VOLTAGE WARNING\r\n"
is a clear indication that your power supply is not well designed and/or
your module is not well decoupled.
It needs >2A current to transmit for a very short time, you need a 100uF
low impedance
in parallel with 2uF MLCC close to the module; or better, what
My view:
Since PPP expects a serial transparent interface, and you are not
providing that, I would write a "tap" which provides that to PPP and
"taps" all other data out.
GSM modem > real serial --> my module -> PPP virtual serial
---> tracking
Hi chrysn,
On Fri, Nov 14, 2014 at 10:09:18AM +0100, chrysn wrote:
> hello lwip users,
>
> i'd like to keep track of my gsm device's position while a ppp data
> connection is active. unfortunately, that means that the non-ppp
> messages (/\r\n+CENG:[0-9,"a-f]+\r\n/ in my case) arrive in the same
hello lwip users,
i'd like to keep track of my gsm device's position while a ppp data
connection is active. unfortunately, that means that the non-ppp
messages (/\r\n+CENG:[0-9,"a-f]+\r\n/ in my case) arrive in the same
stream as ppp messages. (at least, it appears, they are not fully
interleaved)
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