re-uploaded

git-svn-id: https://arducopter.googlecode.com/svn/trunk@952 f9c3cf11-9bcb-44bc-f272-b75c42450872

libraries/APM_RC/APM_RC.cpp

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+/*
+	APM_RC.cpp - Radio Control Library for Ardupilot Mega. Arduino
+	Code by Jordi Muñoz and Jose Julio. DIYDrones.com
+
+	This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+	RC Input : PPM signal on IC4 pin
+	RC Output : 11 Servo outputs (standard 20ms frame)
+
+	Methods:
+		Init() : Initialization of interrupts an Timers
+		OutpuCh(ch,pwm) : Output value to servos (range : 900-2100us) ch=0..10
+		InputCh(ch) : Read a channel input value.  ch=0..7
+		GetState() : Returns the state of the input. 1 => New radio frame to process
+		             Automatically resets when we call InputCh to read channels
+		
+*/
+#include "APM_RC.h"
+
+#include <avr/interrupt.h>
+#include "WProgram.h"
+
+#if !defined(__AVR_ATmega1280__)
+# error Please check the Tools/Board menu to ensure you have selected Arduino Mega as your target.
+#else
+
+// Variable definition for Input Capture interrupt
+volatile unsigned int ICR4_old;
+volatile unsigned char PPM_Counter=0;
+volatile uint16_t PWM_RAW[8] = {2400,2400,2400,2400,2400,2400,2400,2400};
+volatile unsigned char radio_status=0;
+
+/****************************************************
+   Input Capture Interrupt ICP4 => PPM signal read
+ ****************************************************/
+ISR(TIMER4_CAPT_vect)  
+{
+  unsigned int Pulse;
+  unsigned int Pulse_Width;
+  
+  Pulse=ICR4;
+  if (Pulse<ICR4_old)     // Take care of the overflow of Timer4 (TOP=40000)
+    Pulse_Width=(Pulse + 40000)-ICR4_old;  //Calculating pulse 
+  else
+    Pulse_Width=Pulse-ICR4_old;            //Calculating pulse 
+  if (Pulse_Width>8000)   // SYNC pulse?
+    PPM_Counter=0;
+  else
+    {
+    PPM_Counter &= 0x07;  // For safety only (limit PPM_Counter to 7)
+    PWM_RAW[PPM_Counter++]=Pulse_Width;  //Saving pulse. 
+    if (PPM_Counter >= NUM_CHANNELS)
+      radio_status = 1;
+    }
+  ICR4_old = Pulse;
+}
+
+
+// Constructors ////////////////////////////////////////////////////////////////
+
+APM_RC_Class::APM_RC_Class()
+{
+}
+
+// Public Methods //////////////////////////////////////////////////////////////
+void APM_RC_Class::Init(void)
+{
+  // Init PWM Timer 1
+  pinMode(11,OUTPUT); //     (PB5/OC1A)
+  pinMode(12,OUTPUT); //OUT2 (PB6/OC1B)
+  pinMode(13,OUTPUT); //OUT3 (PB7/OC1C)
+
+  //Remember the registers not declared here remains zero by default... 
+  TCCR1A =((1<<WGM11)|(1<<COM1A1)|(1<<COM1B1)|(1<<COM1C1)); //Please read page 131 of DataSheet, we are changing the registers settings of WGM11,COM1B1,COM1A1 to 1 thats all... 
+  TCCR1B = (1<<WGM13)|(1<<WGM12)|(1<<CS11); //Prescaler set to 8, that give us a resolution of 0.5us, read page 134 of data sheet
+  OCR1A = 3000; //PB5, none
+  //OCR1B = 3000; //PB6, OUT2
+  //OCR1C = 3000; //PB7  OUT3
+  ICR1 = 40000; //50hz freq...Datasheet says  (system_freq/prescaler)/target frequency. So (16000000hz/8)/50hz=40000,
+
+  // Init PWM Timer 3
+  pinMode(2,OUTPUT); //OUT7 (PE4/OC3B)
+  pinMode(3,OUTPUT); //OUT6 (PE5/OC3C)
+  pinMode(4,OUTPUT); //     (PE3/OC3A)
+  TCCR3A =((1<<WGM31)|(1<<COM3A1)|(1<<COM3B1)|(1<<COM3C1));
+  TCCR3B = (1<<WGM33)|(1<<WGM32)|(1<<CS31); 
+  OCR3A = 3000; //PE3, NONE
+  OCR3B = 3000; //PE4, OUT7
+  OCR3C = 3000; //PE5, OUT6
+  ICR3 = 40000; //50hz freq
+
+  // Init PWM Timer 5
+  pinMode(44,OUTPUT);  //OUT1 (PL5/OC5C)
+  pinMode(45,OUTPUT);  //OUT0 (PL4/OC5B)
+  pinMode(46,OUTPUT);  //     (PL3/OC5A)
+  
+  TCCR5A =((1<<WGM51)|(1<<COM5A1)|(1<<COM5B1)|(1<<COM5C1)); 
+  TCCR5B = (1<<WGM53)|(1<<WGM52)|(1<<CS51);
+  OCR5A = 3000; //PL3, 
+  //OCR5B = 3000; //PL4, OUT0
+  //OCR5C = 3000; //PL5, OUT1
+  ICR5 = 40000; //50hz freq
+
+  // Init PPM input and PWM Timer 4
+  pinMode(49, INPUT);  // ICP4 pin (PL0) (PPM input)
+  pinMode(7,OUTPUT);   //OUT5 (PH4/OC4B)
+  pinMode(8,OUTPUT);   //OUT4 (PH5/OC4C)
+      
+  TCCR4A =((1<<WGM40)|(1<<WGM41)|(1<<COM4C1)|(1<<COM4B1)|(1<<COM4A1));  
+  //Prescaler set to 8, that give us a resolution of 0.5us
+  // Input Capture rising edge
+  TCCR4B = ((1<<WGM43)|(1<<WGM42)|(1<<CS41)|(1<<ICES4));
+  
+  OCR4A = 40000; ///50hz freq.
+  OCR4B = 3000; //PH4, OUT5
+  OCR4C = 3000; //PH5, OUT4
+ 
+  //TCCR4B |=(1<<ICES4); //Changing edge detector (rising edge). 
+  //TCCR4B &=(~(1<<ICES4)); //Changing edge detector. (falling edge)
+  TIMSK4 |= (1<<ICIE4); // Enable Input Capture interrupt. Timer interrupt mask
+}
+
+void APM_RC_Class::OutputCh(unsigned char ch, uint16_t pwm)
+{
+  pwm=constrain(pwm,MIN_PULSEWIDTH,MAX_PULSEWIDTH);
+  pwm<<=1;   // pwm*2;
+ 
+ switch(ch)
+  {
+    case 0:  OCR5B=pwm; break;  //ch0
+    case 1:  OCR5C=pwm; break;  //ch1
+    case 2:  OCR1B=pwm; break;  //ch2
+    case 3:  OCR1C=pwm; break;  //ch3
+    case 4:  OCR4C=pwm; break;  //ch4
+    case 5:  OCR4B=pwm; break;  //ch5
+    case 6:  OCR3C=pwm; break;  //ch6
+    case 7:  OCR3B=pwm; break;  //ch7
+    case 8:  OCR5A=pwm; break;  //ch8,  PL3
+    case 9:  OCR1A=pwm; break;  //ch9,  PB5
+    case 10: OCR3A=pwm; break;  //ch10, PE3
+  } 
+}
+
+uint16_t APM_RC_Class::InputCh(unsigned char ch)
+{
+  uint16_t result;
+  uint16_t result2;
+  
+  // Because servo pulse variables are 16 bits and the interrupts are running values could be corrupted.
+  // We dont want to stop interrupts to read radio channels so we have to do two readings to be sure that the value is correct...
+  result =  PWM_RAW[ch]>>1;  // Because timer runs at 0.5us we need to do value/2
+  result2 =  PWM_RAW[ch]>>1;
+  if (result != result2)
+    result =  PWM_RAW[ch]>>1;   // if the results are different we make a third reading (this should be fine)
+  
+  // Limit values to a valid range
+  result = constrain(result,MIN_PULSEWIDTH,MAX_PULSEWIDTH);
+  radio_status=0; // Radio channel read
+  return(result);
+}
+
+unsigned char APM_RC_Class::GetState(void)
+{
+  return(radio_status);
+}
+
+// InstantPWM implementation
+// This function forces the PWM output (reset PWM) on Out0 and Out1 (Timer5). For quadcopters use
+void APM_RC_Class::Force_Out0_Out1(void)
+{
+  if (TCNT5>5000)  // We take care that there are not a pulse in the output
+    TCNT5=39990;   // This forces the PWM output to reset in 5us (10 counts of 0.5us). The counter resets at 40000
+}
+// This function forces the PWM output (reset PWM) on Out2 and Out3 (Timer1). For quadcopters use
+void APM_RC_Class::Force_Out2_Out3(void)
+{
+  if (TCNT1>5000)
+    TCNT1=39990;
+}
+// This function forces the PWM output (reset PWM) on Out6 and Out7 (Timer3). For quadcopters use
+void APM_RC_Class::Force_Out6_Out7(void)
+{
+  if (TCNT3>5000)
+    TCNT3=39990;
+}
+
+// make one instance for the user to use
+APM_RC_Class APM_RC;
+
+#endif // defined(ATMega1280)

libraries/APM_RC/APM_RC.h

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+#ifndef APM_RC_h
+#define APM_RC_h
+
+#define NUM_CHANNELS 8
+#define MIN_PULSEWIDTH 900
+#define MAX_PULSEWIDTH 2100
+
+#include <inttypes.h>
+
+class APM_RC_Class
+{
+  private:
+  public:
+	APM_RC_Class();
+	void Init();
+	void OutputCh(unsigned char ch, uint16_t pwm);
+	uint16_t InputCh(unsigned char ch);
+	unsigned char GetState();
+	void Force_Out0_Out1(void);
+	void Force_Out2_Out3(void);
+	void Force_Out6_Out7(void);
+};
+
+extern APM_RC_Class APM_RC;
+
+#endif

libraries/APM_RC/keywords.txt

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+APM_RC	KEYWORD1
+begin	KEYWORD2
+InputCh	KEYWORD2
+OutputCh	KEYWORD2
+GetState	KEYWORD2
+Force_Out0_Out1	KEYWORD2
+Force_Out2_Out3	KEYWORD2
+Force_Out6_Out7	KEYWORD2