Hi guys,this afternoon, left my busyness, I focused my mind in writing a simple code (for PICs), a 16F887 micro, to "capture" the raising and falling ramp of a pulses out of my Futaba receiver FP-R129DP in order to be captured by the micro.Not a big problem to deal with...just few instructions to use the built-in "capture" hardware function in the micro.Problems started when I tried to visualize on my pc, by my pc-based scope, the waveform and timing between every pulses coming out from the receiver...Let's say that I was disappointed when I discovered that pulses from Servo_1 and Servo_2 (Aileron and Elevator) overlap each other and the same for Servo_3 and Servo_4 (Throttle and Rudder)!!!I took a picture of waveforms:
Red line is Aileron signal and blue is Elevator signal, they overlap exactly.Overlapping make it impossible to capture the raising and falling edges of a pulse for both Aileron and Elevator in the same time.So, do you know how is it possible to take the timing of a pulses when both overlap??I read in Paparazzi site that the signal (PPM mode) must be take before it reaches the servos, by soldering a wire before the multiplexer..Is this the only possible solution?Thank you very muchDave
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Just grab every other pair of pulses, alternating between channels? We do it all the time with Arduino. Just PulseIn until you get a reading, then do the same with the next channel. If you write efficient code, you should be able to get through all of your channels fast enough that you won't miss any significant change.
This is standard stuff. You just need to sample the pulses pretty often, not grab every one.
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This is standard stuff. You just need to sample the pulses pretty often, not grab every one.