Fixed GSM Terminal

[dsk]

The cabin has no telephone connection, and cellphones are not that expensive.
;)Step 1 Convince the family about the need of getting the old alarm-system ringing me and telling its an alarm.
;)Step 2 By a lo cost unit at ebay. http://tinyurl.com/cl45q46
;)Step 3 Testing it out at home.
and that's whats going home just now:
Setup at the pictures: GSM terminal, Dialgizmo, Old jack, and a W.E. 500 1961, trustable, and maybe one best on line impedance matching.  Hoff hook current measured to 18.5 milliamps.
Click on the last pic to hear the ringing.

 


dsk

[twocvbloke]

That's pretty neat, though I have to say, the ringer cadence sounds a bit short for a US-type ring (assuming that's what is aimed for), but otherwise seems pretty cool...

I've looked at those chinese GSM gateways, and now someone has one, does it have any connection to hook it up to a computer (E.G. for data, altering settings, etc.)? If so, it'd definitely look like a good candidate to play with...

[dsk]

  No PC interface, and the manual..
English is not my native language, so maybe that's why, but I rater guess its some google translate from Chinese.

I had to use my phone to set the sim-card with no PIN code, and then it was plug and play.
It sounds like it is sending caller id as DTMF, so it should be possible to get that info with a an extra box, and it is displayed on the unit itselves.

So far I have only been able to use the programming for setting date, and time.
All hints are welcome, the manual: http://www.scribd.com/doc/96281338/Gsm-Pots-Adapter

dsk

[twocvbloke]

Yeah, most manuals that come with devices that originate over in the PRC are virtually impossible to understand, as they literally translate from chinese to chinglish, and don't bother actually verifying that it's correct...

I think about all you really need to do with it is just set the date and time, the rest just seems to be about setting call charge rates and stuff which makes no sense, as the mobile providers do that for you, I guess china does it all differently...

Not sure about the PIN number stuff, again, it makes no sense what they're saying...

There's a good reason why I prefer not to buy stuff from over there...

[dsk]

That's my kind of gambling 
The unit works well, the phone rings, the echo canselling software uses a few seconds to optimise, and when the Sim card is put in with no code, everyting just works. 
The cost of the only gsm terminal I found here are approx 7.5 times the price of the eBay unit.
Actually it is so good, I have desired to test it during the summer, and see if it should replace my landline.
(Just to save money) The cost of a landline as we have it now are high, $27.5 pr month, and 0 for cellphone, and still the use are 2.5 times as expensive.
The tel-co has stated to evaluate to shut down the POTS system due to high cost maintaining the copper net. They still deliver ADSL (vi copper net) so I don't understand this

dsk

[twocvbloke]

Yeah, there's always talk of telcos shutting down POTS systems, but, it's so integrated into the countries involved that if they took it away, there'd be many without communications, as not everyone has access to the internet (be it cos they don't have computers, or have any need for it, like most elderly people), and as you say, they carry the ADSL signals to customers as they don't actually do fibre up to houses as yet, so they can't basically get rid just because it's expensive, they have to fine better ways to build and maintain (and secure from metal thieves) the copper...

As for the GSM Terminal, I think I'd go for a name-brand one, like Nokia, Ericsson or Huawei (the latter makes 3G products, of which I have one (E156G 3G USB modem)), cos at least then you can get instructions that have been properly written, and easily accessible features...

[dsk]

  I shouldn't opened it, and breaking the seal 
For real its no warranty, shipping are to expensive so I opened it:

dsk

[twocvbloke]

Blummin' heck!!! That looks like the guts of an old Nokia 6210 in there!!!

I doubt they'd actually comply with the warranty anyway, that phone PCB is most likely a used part, and thus wouldn't actually be covered under any sane warranty here in the western part of the world...

I think I'll definitely avoid these GSM terminals, that's some pretty dubious hardware for sure....

[Owain]

so that's what happens to old phones sent to China for recycling   

[dsk]

Now it is really tested out. Connected to our Securitas alarm, and tested several times, all messages OK..

Next is to put it up at the cabin 

dsk

[dsk]

Now it has been working for about 1 year.
I have connected one alarm system, one remote power-switch and 2 telephones a 500 and a 2500. (and of course the Dialgizmo.)

All this made the ring signal to weak, so I have added a relay and ringing generator so now I have grounded ringing and 20Hz for the telephones.

Great fun 

dsk

[twocvbloke]

It's a year already? Doesn't seem that long ago...