Yes, you have picked a very challenging project.
The servo part broken down into basic steps of what is going on here. (Other interrupt sources, and different timers could be substituted, but this is what I am using).
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Pulse Sensing:
Using CCP interrupt and calculate (pulse_width = falltime - risetime) with CCP capture low byte CCPR1L and capture high byte CCPR1H (these use Timer1). To do this, bits must be changed from capture on rise, to capture on fall.
Pulse Width Generation:
Need to create interrupt from about 1ms to 2ms in length. To do this, we load a timer with pulse width value, bring servo pin high, start timer, when interrupt occurs, bring servo pin low. I used Timer0.
Pulse Period Generation:
Need to generate 20ms time frame for sending servo signals. I used Timer2. Servo out pins need to pulse every 20 ms.
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On a side note:
Now just to discombobulate things a little bit (more!), cheating can sometimes work. Problem is, that you want to run one of your outputs through a motor controller, and these don't like cheaters. They like very reliable 20ms time (Pulse Period) frames for the servo pulses. So, where you might have gotten away with using PBP's pulsin and pulsout commands for sensing and controlling servo's, you will not get away with using the pulsout command for controlling your motor controller.
One place you could get away with a little cheating, is to use Pulsin command to sense your receiver's servo pulses. Then you would not have to worry about the servo Pulse Width sensing. I have used this with an RC autopilot project, and it was smooth enough to fly. But, since you are doing all this work learning about interrupts, and timers, you might as well do it the right way, and measure the pulse with an interrupt.
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