Comments on: Mini GSM localizer without GPS

By: BorisLandoni

BorisLandoni — Fri, 02 Nov 2012 08:19:00 +0000

Hi, in the post you can find also the source code.
The USB is only to charge the battery

By: Ping

Ping — Wed, 24 Oct 2012 06:26:00 +0000

I am interested with this Mini GSM localizer without GPS. However, I would like to integrate it with my own GPS tracker. Is that possible? Can I modify the programming to suit my requirement? The USB port in this circuit is for programming purpose or other purpose? This circuit requires external antenna?

By: BorisLandoni

BorisLandoni — Mon, 22 Oct 2012 08:07:00 +0000

? There is a link to download the firmware
http://www.open-electronics.org/wp-content/uploads/2011/06/FT908_GoogleLocalizator.zip

By: Mrunal

Mrunal — Fri, 19 Oct 2012 13:42:00 +0000

Good work! and thanks for sharing!!! but If I could get to know the code then its better than good…!

By: Boris Landoni

Boris Landoni — Mon, 27 Aug 2012 16:04:23 +0000

@RandomWireMan
I tried also OpenCellID, but Google has a more detailed database….
You can do some test with my page:
http://www.open-electronics.org/how-to-find-the-location-with-gsm-cells/

By: Boris Landoni

Boris Landoni — Mon, 27 Aug 2012 16:01:10 +0000

@jackjr
Yes you are right, but is also 3.6 volt tollerant.

VBAT:
Vmax= 4.5V
Vmin=3.4V
Vnorm=4.0V

Serial Port
VILmax=0.15 *VDD_EXT
VIHmin=0.85*VDD_EXT
VILmin= 0V
VIHmax= VDD_EXT
VOHmin= VDD_EXT-0.1V
VOLmax=0.1V
VOHmax= VDD_EXT
VOLmin= 0V

By: RandomWireMan

RandomWireMan — Sun, 26 Aug 2012 15:20:25 +0000

Hi Boris,

I was firing away too quickly. Googles and sonys location api work with both versions of the cell-id. Only OpenCellIDs api doesn’t work on the version I get with my sim900 module. Looks like a database problem.
Do you think it is possible that different modules spit out different cell-ids?

Cheers,

RandomWireMan

By: RandomWireMan

RandomWireMan — Sun, 26 Aug 2012 13:33:36 +0000

Hi Boris,

I am working on a similar project also with a SIM900 module.
If I read ‘AT+CREG?’ i get ‘ +CREG: 2,1,”2775″,”A225″‘ which translates to me as 41509(dec) for cellid and 10101 for lac.
This gives me wrong coordinates though. If I use my mobile(CellIDCollector),it tells me 7401133(dec) for cellid and 11528(dec) for lac. This gives me the correct coordinates.
Can you tell me what I am missing here?

Thanks a lot

RandomWireMan

By: jackjr

jackjr — Sun, 05 Aug 2012 14:08:21 +0000

Hi Boris,

There is something I don’t understand in your circuit.
The SIM900 UART works at 2.8V levels. But you are using a 3.6V power supply.

How can this be?

By: Boris Landoni

Boris Landoni — Wed, 27 Jun 2012 15:29:38 +0000

Hi, I didn’t find problem with GPRS connection and SMS, I don’t know what could be happened.
Doyou have other information?

By: Pranav

Pranav — Tue, 26 Jun 2012 21:30:15 +0000

Hi Boris,

i made a similar board as yours and observed a strange issue. When sim module is connected to gprs and at the same time sms is received it crashes.
can you advice what could be the fault? i also tried increasing the electrolyte capacitors from 1 to 5 470uF capacitors but it didn’t helped

Thanks
Pranav

By: Mat

Mat — Wed, 13 Jun 2012 23:59:46 +0000

Hi!

Could you give more information about switches? I want to buy but I don’t know which model is correct