Just confirming: from looking over the ‘Arduino Connector’ on the GPRS schematic, it doesn’t appear that hardware flow control of the cellular modem is supported. Is this correct?
The CTS and RTC is not connected to Arduino pins, but they have been brought out. You can see them on the board.
That will work! Thanks for the quick reply.
A follow-up (sorry!): the UART header where the CTS/RTS/etc pins are brought out is labled (2V8). Will there be any issues interfacing the UART with a 3V3 host (like my Netduino) via this header? And what is the maximum safe supply voltage for the EXT_PWR header?
the Pins of sim900 are 2V8 , so, there is a mosfet to convert the Tx and Rx to 5v. as your application, i am not sure whether 2V8 logic would apply 3v3 logic, maybe you need a try. power supply on EXT_pwr should be 5V. thanks.