micro-hopless
Member level 1
I'm using a SIM900 modem for connecting to a GPRS network, but the stupid modem will not recognize ANY SIM attached to it !
I have double, triple quadruple check the SIM connections but it won't work !.
I have zero volts on SIM_VDD pin, with 10uF cap to ground. The SIM_PRESENCE pin is connected to ground.
Modem responds to all AT commands, and is still in autobauding mode, which I wish to keep.
What is wrong?
I have double, triple quadruple check the SIM connections but it won't work !.
I have zero volts on SIM_VDD pin, with 10uF cap to ground. The SIM_PRESENCE pin is connected to ground.
Modem responds to all AT commands, and is still in autobauding mode, which I wish to keep.
What is wrong?