We are developing an application with GL6100/GL6110 which will interface via serial port to a micro-controller based device. We are embedding our Open AT application code in the GL61xx modem to control the GSM and GPRS TCP/IP communication links but are seeking advice on who should be the master controller (a host versus client question).
Our core method is to use the GL61xx as the “master” controller which will send instructions to the external micro-controller via the serial link (USB or RS232). In this case the external micro-controller simply waits and listens to its RX serial port for communication. In this case we only want to send the external controller specific commands as and when is needed and not all the information down the serial port when received and processed by the GL61xx. In a sense we wish to prevent/control GL61xx TX but still keep the GL61xx RX open for instructions from the external device. Is this possible. What AT commands would we use. Are there any traps to avoid (e.g. read about someone who put their GL61xx to deep sleep and could not wake because serial port had been disabled etc.)
The alternative option is to have the external micro controller as the master controller (similar to a PC) which then listens to everything received by the GL1xx modem. But this way we feel we are under utilising the programmable modems features.
Look forward to feedback.