/elec/quadcopter

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16 by Tim Marston
added (unfinished) rc-interface module to src; added arduino.mk
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//
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// main.ino
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//
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// This software is intended to be run on a small Arduino (e.g., a Pro Mini),
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// whose purpose is dedicated to talking to the RC system.  That is to say, it
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// listens to the PPM signal from the RC receiver and produces a compatible
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// single for the ESCs to control the motors.  It additionally talks to the main
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// board via a trivial serial protocol.  In so doing, this software relieves the
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// main board (and software running on it) of the task of interfacing with any
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// of the RC system.
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//
17 by Tim Marston
rc-interface: mostly completed it (untested, but rx and tx code should work)
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// Receiver
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// --------
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//
16 by Tim Marston
added (unfinished) rc-interface module to src; added arduino.mk
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// The 8 channels (from the RC receiver) need to be combined and fed to two
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// interrupts on the Arduino.  They need to be combined in such a way as to
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// alternate pulses between the two interrupts (which are alternately used to
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// read the pulses).  Like this:
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//
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//                  ch1  ch3  ch5  ch7  ch2  ch4  ch6  ch8
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//                   |    |    |    |    |    |    |    |
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//                   ▼    ▼    ▼    ▼    ▼    ▼    ▼    ▼
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//                   ¯    ¯    ¯    ¯    ¯    ¯    ¯    ¯
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//            ___    |    |    |    |    |    |    |    |     ___
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//    GND ---|___|---+----+----+----+    +----+----+----+----|___|--- GND
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//             R                    |    |                     R
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//             ____________________ | __ | _____________________
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//                                  |    |
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//                           pin 2  o    o  pin 3
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//                    (interrupt 0)        (interrupt 1)
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//
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// The two resistors in the circuit are pull-down resistors (so, say 100kΩ).
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// Without them, the Arduino is unable to read the pulse wave at all.
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//
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// Note that your receiver may not send pulses sequentially, in "channel order".
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// If this turns out to be the case, you will need to arrange for the pulses to
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// wire up the channels in an order whereby the pulses alternatively alternately
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// between the two interrupts and adjust the channel order below.
17 by Tim Marston
rc-interface: mostly completed it (untested, but rx and tx code should work)
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//
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// Motor control
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// -------------
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//
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// 
16 by Tim Marston
added (unfinished) rc-interface module to src; added arduino.mk
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#include "config.h"
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#include "receiver.h"
17 by Tim Marston
rc-interface: mostly completed it (untested, but rx and tx code should work)
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#include "motors.h"
18 by Tim Marston
completed (hopefully) the RC interface software
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#include "comms.h"
16 by Tim Marston
added (unfinished) rc-interface module to src; added arduino.mk
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void setup()
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{
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	Receiver::setup();
17 by Tim Marston
rc-interface: mostly completed it (untested, but rx and tx code should work)
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	Motors::setup();
18 by Tim Marston
completed (hopefully) the RC interface software
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	Comms::setup();
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	// led
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	pinMode( LED_PIN, OUTPUT );
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	digitalWrite( LED_PIN, LOW );
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}
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void flash_led()
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{
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	static bool on = false;
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	on = !on;
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	digitalWrite( LED_PIN, on? HIGH : LOW );
16 by Tim Marston
added (unfinished) rc-interface module to src; added arduino.mk
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}
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void loop()
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{
18 by Tim Marston
completed (hopefully) the RC interface software
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	int channel_values[ NUM_CHANNELS ];
16 by Tim Marston
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	while( true )
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	{
18 by Tim Marston
completed (hopefully) the RC interface software
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		// have we read a whole set of channel values?
16 by Tim Marston
added (unfinished) rc-interface module to src; added arduino.mk
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		if( Receiver::read_channels( channel_values ) )
17 by Tim Marston
rc-interface: mostly completed it (untested, but rx and tx code should work)
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		{
18 by Tim Marston
completed (hopefully) the RC interface software
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			// yes, flash led!
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			flash_led();
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			// send channel values to main board
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			Comms::write_channels( channel_values );
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			// set motor speeds
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			Motors::set_values( channel_values );
17 by Tim Marston
rc-interface: mostly completed it (untested, but rx and tx code should work)
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		}
18 by Tim Marston
completed (hopefully) the RC interface software
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		// update motors
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		Motors::update();
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added (unfinished) rc-interface module to src; added arduino.mk
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	}
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}