Hi,
I would like to make sim900 support multi sim cards(20~40). I don't need all of my sim cards working at the same time. So I just need to poll each of them.
My idea is to select the sim cards connected to sim900 using I2C.
Is there any I2C slave IC supporting SIM card? I did some search but found nothing. Or is there any better way to complete my project?
Please let me know your idea, thanks.
The problem is more the switching of the 3/4 lines between the Sim Card and the Sim900 chip.
Each one will require is own sim holder, line switches and i2c decoding and then 20-40 of these all on a pcb ??
Not to mention the programming and the display / menu system you need on the Arduino to select the required Sim.
Think you need to say why you need so many Sims and if this is a true project for yourself or just a college test.
I think maybe you should consider giving more background to your project. Each time you switch sim, you'll start a fresh network search, then registration, then delay while you wait for the response from whatever you want (Im guessing its SMS), then you want to deregister. I wouldnt be surprised if that took 2-5 minutes per SIM.
Thanks for the feedback.
I have many sim cards, each of them will receive one sms each day. So I don't need all of them stand by all the time.