/elec/quadcopter

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1 by Tim Marston
initial commit, and a couple of receiver test programs
1
//
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// main.ino
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//
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// Testing reading from the receiver.  We're expecting a PWM signal, on
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// interrupt 0 (which is pin 2 on an Arduino Uno).
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//
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// This program tries to measure the frequency of the signal pulses in
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// microseconds.  It takes several measurements and prints out the average over
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// serial.
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//
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// number of signal pulses to average
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#define SIGNAL_SAMPLES 10
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// set to the time that the last signal pulse was at
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static volatile unsigned long _new_pulse_at = 0;
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// ISR to handle the PWM signal
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void signal_handler()
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{
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	// record time
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	_new_pulse_at = micros();
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}
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void setup()
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{
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	Serial.begin( 9600 );
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	// set up an interrupt handler on pin 2
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	attachInterrupt( 0, signal_handler, RISING );
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}
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void loop()
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{
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	unsigned long last_pulse = 0;
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	unsigned long intervals[ SIGNAL_SAMPLES ] = {0};
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	int interval_idx = 0;
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	while( true )
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	{
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		// detect pulse
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		unsigned long new_pulse = _new_pulse_at;
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		bool got_pulse = false;
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		if( new_pulse < last_pulse )
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			last_pulse = new_pulse;
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		if( new_pulse > last_pulse )
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		{
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			// check interval
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			unsigned long interval = new_pulse - last_pulse;
6 by Tim Marston
fixed receiver test code which is now working
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			if( false && interval < 300 )
1 by Tim Marston
initial commit, and a couple of receiver test programs
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			{
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				Serial.print( "[" );
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				Serial.print( last_pulse );
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				Serial.print( "," );
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				Serial.print( new_pulse );
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				Serial.print( "]" );
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			}
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//			if( interval > 19000 && interval < 20500 )
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//			{
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				// update interval buffer
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				intervals[ interval_idx ] = interval;
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				if( ++interval_idx >= SIGNAL_SAMPLES )
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					interval_idx = 0;
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				got_pulse = true;
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//			}
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			last_pulse = new_pulse;
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		}
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		// display average?
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		if( interval_idx == 0 && got_pulse )
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		{
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			// calculate average
6 by Tim Marston
fixed receiver test code which is now working
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			long interval = 0;
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			for( int a = 0; a < SIGNAL_SAMPLES; a++ )
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				interval += intervals[ a ];
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			Serial.print( intervals[ 0 ] );
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			Serial.println();
1 by Tim Marston
initial commit, and a couple of receiver test programs
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		}		
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	}
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}