select multi sim cards in sim900 using i2c

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hi,
i make sim900 support multi sim cards(20~40). don't need of sim cards working @ same time. need poll each of them.
my idea select sim cards connected sim900 using i2c.
is there i2c slave ic supporting sim card? did search found nothing. or there better way complete project?

please let me know idea, thanks.

the problem more switching of 3/4 lines between sim card , sim900 chip.

each 1 require own sim holder, line switches , i2c decoding , 20-40 of these on pcb ??

not mention programming , display / menu system need on arduino select required sim.

think need why need many sims , if true project or college test.


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