iM WORKING ON A project where i have to interface an 89c51 microcontroller with a GPS module and GSM mobile phone. Should i use a microcontroler with 2 serial ports? If so, which micros come with 2 serial ports. Do all micros with 3rd timer have a second serial port. What are the pins for the 2nd port?
In my case there is no need for simultaneous communication. Is it then possible to use a mC with a single port and use some ind of multiplexres, select lines transceivers etc. pls help
sathish
For this application there is no need for micro with 2 serial ports.
Most of GPSs doesn't even use RS-232 levels, instead they send out strings of 0-5V which can be directly connected to an AND or NAND gate(s) and by using additional pin from your micro you can select a device. Once you fetch desirable info from GPS switch to GSM. You have almost 1s before updated info from GPS is available..