SKM53 GPS Module Need Help !!!

[has_mmu]

The default rate for the module is 9600 and i am using 20MHz with PIC18F4550.
FYI i am using SN7407N to convert the 2.8 TTL to 5V TTL.
It got stuck at (PIR1bits.RCIF) Condition...

I am connecting th TX(GPS)---> SN7407N ---->RX(PIC18F4550)
If this project is success, i will share the code for this GPS module.

Finally i found something is wrong with SN7407N.
The ouput(the pin is open) is between 5v-0v if input is 2.8v-0v.

BUT if i connect to the PIC(RX), the voltage is dropped if i connect supply of 2.8V(Voltage divider).
I set the RX pin to be input and it obviously cant show it will be '1' logic.
This SHOW the 5v signal is dropped due to the low output current.

I plan to use OP-AMP(As a Buffer ) due to limited time i have.


One more question ...is it possible to use op-amp(as amplifier) to act as level shifter from 2.8v to 5v?
If this is possible, this will simplify the circuit.

Thanks

[sich]

How did you connect the GPS TX to SN7404N and PIC RX?

[shahrul]

I have interface GPS Receiver using PIC16F887, see video PIC GPS Receiver.