Arduino Forum

Using Arduino => Project Guidance => Topic started by: MrMr on Jun 30, 2014, 09:49 am

Title: Dual sim
Post by: MrMr on Jun 30, 2014, 09:49 am
Hi

Have anyone succesfully used arduino with dual sim?

I need to send a sms when i get a input on the arduino. But because it is very unstable, i need 2 have 2 sim cards. Does anyone know of a simlar project that have written about it?
Title: Re: Dual sim
Post by: holmes4 on Jun 30, 2014, 12:08 pm
What do you mean by "unstable". Why do you think a dual sim would fix it? Sounds like you have a hardware problem, power, bad wiring or something.

Start there.

Mark
Title: Re: Dual sim
Post by: MrMr on Jun 30, 2014, 12:49 pm

What do you mean by "unstable". Why do you think a dual sim would fix it? Sounds like you have a hardware problem, power, bad wiring or something.

Start there.

Mark


Hi

Thank you for the answer. I am sorry i was not clear in my post. The problem is not hardware related, but the GSM network that is unstable. So the dual sim will help, because it will use 2 diffrent GSM networks.
Title: Re: Dual sim
Post by: Nick_Pyner on Jun 30, 2014, 04:55 pm

Have anyone succesfully used arduino with dual sim?


I haven't done it, but it should not be a problem. The typical SIM board has jumper to use software serial or hardware serial. Therefore you should be able to simply stack two differently-configured shields. If you were desperate enough you could continue the saga with more shields
Title: Re: Dual sim
Post by: Zapro on Jun 30, 2014, 07:44 pm
Have a look at this circuit, if it works with a SD-card, it will work with a SIM too.
http://hackaday.com/2014/06/08/the-in-circuit-sd-card-switch/ (http://hackaday.com/2014/06/08/the-in-circuit-sd-card-switch/)

Simply, power down the GSM modem, switch the card and power it on again.

If the GSM modem has a pin for signaling "Sim-card-holder open" you could use that too, signaling the GSM modem that the card was removed and re-inserted, without powering down the modem.

// Per.
Title: Re: Dual sim
Post by: MrMr on Jul 01, 2014, 09:44 am

Have a look at this circuit, if it works with a SD-card, it will work with a SIM too.
http://hackaday.com/2014/06/08/the-in-circuit-sd-card-switch/ (http://hackaday.com/2014/06/08/the-in-circuit-sd-card-switch/)

Simply, power down the GSM modem, switch the card and power it on again.

If the GSM modem has a pin for signaling "Sim-card-holder open" you could use that too, signaling the GSM modem that the card was removed and re-inserted, without powering down the modem.

// Per.


Thank you. I will look into that. Think it is what i am looking for.