How to produce variable frequency sqare Wave on PIC 18

[Skywalker]

I want to use a PIC18F242 to produce a square wave with variable frequency between 50Hz an 3khz. On the datasheet I found that I can use CCP1 module for doing this. Toggle the CCP1 Pin on matching Timer1 an reset Timer 1 over the Special event Triger.

My problem is now, how to do this in C
I can't use interrupts for this, because I want to make a tone with this sqare wave and have to do some RS232 actions wich last more than a time between switching for a 3khz signal.

The Pic is running on 20mhz
Timer is is dived by 2
But with

[Mark]

Piece of cake to do the frequency. And yes you can do it with interrupts and still have RS232. The PIC has a hardware UART so it doesn't require any of the processor resources except to load or read a register. The overhead for the square wave should be very small. Set the CCP to toggle the pin and just keep adding the period value to the CCP register. This will cancel out any latency.