mirror of https://github.com/ArduPilot/ardupilot
745 lines
24 KiB
C
745 lines
24 KiB
C
// Warning : Untested - Please use version 2.2.63 for field use.
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// -------------------------------------------------------------
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// PPM ENCODER V2.2.65 (25-09-2011)
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// -------------------------------------------------------------
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// Improved servo to ppm for ArduPilot MEGA v1.x (ATmega328p)
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// and PhoneDrone (ATmega32u2)
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// By: John Arne Birkeland - 2011
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// APM v1.x adaptation and "difficult" receiver testing by Olivier ADLER
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// -------------------------------------------------------------
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// Changelog:
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// 01-08-2011
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// V2.2.3 - Changed back to BLOCKING interrupts.
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// Assembly PPM compare interrupt can be switch back to non-blocking, but not recommended.
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// V2.2.3 - Implemented 0.5us cut filter to remove servo input capture jitter.
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// 04-08-2011
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// V2.2.4 - Implemented PPM passtrough funtion.
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// Shorting channel 2&3 enabled ppm passtrough on channel 1.
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// 04-08-2011
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// V2.2.5 - Implemented simple average filter to smooth servo input capture jitter.
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// Takes fewer clocks to execute and has better performance then cut filter.
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// 05-08-2011
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// V2.2.51 - Minor bug fixes.
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// 06-08-2011
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// V2.2.6 - PPM passtrough failsafe implemented.
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// The PPM generator will be activated and output failsafe values while ppm passtrough signal is missing.
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// 01-09-2011
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// V2.2.61 - Temporary MUX pin always high patch for APM beta board
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// 22-09-2011
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// V2.2.62 - ATmegaXXU2 USB connection status pin (PC2) for APM UART MUX selection (removed temporary high patch)
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// - Removed assembly optimized PPM generator (not usable for production release)
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// 23-09-2011
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// V2.2.63 - Average filter disabled
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// 24-09-2011
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// V2.2.64 - Added distincts Power on / Failsafe PPM values
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// - Changed CH5 (mode selection) PPM Power on and Failsafe values to 1555 (Flight mode 4)
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// - Added brownout detection : Failsafe values are copied after a brownout reset instead of power on values
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// 25-09-2011
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// V2.2.65 - Implemented PPM output delay until input signal is detected (PWM and PPM pass-trough mode)
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// - Changed brownout detection and FailSafe handling to work with XXU2 chips
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// - Minor variable and define naming changes to enhance readability
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// -------------------------------------------------------------
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#ifndef _PPM_ENCODER_H_
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#define _PPM_ENCODER_H_
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#include <avr/io.h>
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// -------------------------------------------------------------
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#include <avr/interrupt.h>
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#include <avr/wdt.h>
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#include <util/delay.h>
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// -------------------------------------------------------------
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// SERVO INPUT FILTERS
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// -------------------------------------------------------------
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// Using both filters is not recommended and may reduce servo input resolution
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// #define _AVERAGE_FILTER_ // Average filter to smooth servo input capture jitter
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// #define _JITTER_FILTER_ // Cut filter to remove 0,5us servo input capture jitter
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// -------------------------------------------------------------
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#ifndef F_CPU
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#define F_CPU 16000000UL
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#endif
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#ifndef true
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#define true 1
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#endif
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#ifndef false
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#define false 0
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#endif
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#ifndef bool
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#define bool _Bool
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#endif
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// -------------------------------------------------------------
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// SERVO INPUT MODE - !EXPERIMENTAL!
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// -------------------------------------------------------------
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#define JUMPER_SELECT_MODE 0 // Default - PPM passtrough mode selected if channel 2&3 shorted. Normal servo input (pwm) if not shorted.
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#define SERVO_PWM_MODE 1 // Normal 8 channel servo (pwm) input
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#define PPM_PASSTROUGH_MODE 2 // PPM signal passtrough on channel 1
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#define JETI_MODE 3 // JETI on channel 1 (reserved but not implemented yet)
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#define SPEKTRUM_MODE 4 // Spektrum satelitte on channel 1 (reserved but not implemented yet)
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// Servo input mode (jumper (default), pwm, ppm, jeti or spektrum)
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volatile uint8_t servo_input_mode = JUMPER_SELECT_MODE;
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// -------------------------------------------------------------
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// Number of Timer1 ticks in one microsecond
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#define ONE_US F_CPU / 8 / 1000 / 1000
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// 400us PPM pre pulse
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#define PPM_PRE_PULSE ONE_US * 400
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// -------------------------------------------------------------
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// SERVO LIMIT VALUES
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// -------------------------------------------------------------
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// Servo minimum position
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#define PPM_SERVO_MIN ONE_US * 900 - PPM_PRE_PULSE
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// Servo center position
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#define PPM_SERVO_CENTER ONE_US * 1500 - PPM_PRE_PULSE
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// Servo maximum position
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#define PPM_SERVO_MAX ONE_US * 2100 - PPM_PRE_PULSE
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// Throttle default at power on
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#define PPM_THROTTLE_DEFAULT ONE_US * 1100 - PPM_PRE_PULSE
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// Throttle during failsafe
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#define PPM_THROTTLE_FAILSAFE ONE_US * 900 - PPM_PRE_PULSE
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// CH5 power on values (mode selection channel)
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#define PPM_CH5_MODE_4 ONE_US * 1555 - PPM_PRE_PULSE
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// -------------------------------------------------------------
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// Number of servo input channels
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#define SERVO_CHANNELS 8
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// PPM period 18.5ms - 26.5ms (54hz - 37Hz)
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#define PPM_PERIOD ONE_US * ( 22500 - ( 8 * 1500 ) )
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// Size of ppm[..] data array ( servo channels * 2 + 2)
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#define PPM_ARRAY_MAX 18
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// Data array for storing ppm (8 channels) pulse widths.
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volatile uint16_t ppm[ PPM_ARRAY_MAX ] =
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{
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 1
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 2
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PPM_PRE_PULSE,
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PPM_THROTTLE_DEFAULT, // Channel 3 (throttle)
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 4
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PPM_PRE_PULSE,
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PPM_CH5_MODE_4, // Channel 5
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 6
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 7
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 8
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PPM_PRE_PULSE,
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PPM_PERIOD
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};
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// -------------------------------------------------------------
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// SERVO POWER ON VALUES
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// -------------------------------------------------------------
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/*
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const uint16_t power_on_ppm[ PPM_ARRAY_MAX ] =
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{
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 1
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 2
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PPM_PRE_PULSE,
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PPM_THROTTLE_DEFAULT, // Channel 3 (throttle)
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 4
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PPM_PRE_PULSE,
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PPM_CH5_MODE_4, // Channel 5
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 6
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 7
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 8
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PPM_PRE_PULSE,
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PPM_PERIOD
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};
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*/
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// -------------------------------------------------------------
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// -------------------------------------------------------------
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// SERVO FAILSAFE VALUES
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// -------------------------------------------------------------
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const uint16_t failsafe_ppm[ PPM_ARRAY_MAX ] =
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{
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 1
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 2
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PPM_PRE_PULSE,
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PPM_THROTTLE_FAILSAFE, // Channel 3 (throttle)
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 4
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PPM_PRE_PULSE,
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PPM_CH5_MODE_4, // Channel 5
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 6
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 7
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PPM_PRE_PULSE,
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PPM_SERVO_CENTER, // Channel 8
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PPM_PRE_PULSE,
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PPM_PERIOD
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};
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// -------------------------------------------------------------
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// AVR parameters for PhoneDrone PPM Encoder and future boards also using ATmega16-32u2
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#if defined (__AVR_ATmega16U2__) || defined (__AVR_ATmega32U2__)
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#define SERVO_DDR DDRB
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#define SERVO_PORT PORTB
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#define SERVO_INPUT PINB
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#define SERVO_INT_VECTOR PCINT0_vect
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#define SERVO_INT_MASK PCMSK0
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#define SERVO_INT_CLEAR_FLAG PCIF0
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#define SERVO_INT_ENABLE PCIE0
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#define SERVO_TIMER_CNT TCNT1
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#define PPM_DDR DDRC
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#define PPM_PORT PORTC
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#define PPM_OUTPUT_PIN PC6
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#define PPM_INT_VECTOR TIMER1_COMPA_vect
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#define PPM_COMPARE OCR1A
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#define PPM_COMPARE_FLAG COM1A0
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#define PPM_COMPARE_ENABLE OCIE1A
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#define USB_DDR DDRC
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#define USB_PORT PORTC
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#define USB_PIN PC2
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// true if we have received a USB device connect event
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static bool usb_connected;
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// USB connected event
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void EVENT_USB_Device_Connect(void)
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{
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// Toggle USB pin high if USB is connected
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USB_PORT |= (1 << USB_PIN);
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usb_connected = true;
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// this unsets the pin connected to PA1 on the 2560
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// when the bit is clear, USB is connected
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PORTD &= ~1;
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}
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// USB disconnect event
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void EVENT_USB_Device_Disconnect(void)
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{
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// toggle USB pin low if USB is disconnected
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USB_PORT &= ~(1 << USB_PIN);
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usb_connected = false;
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// this sets the pin connected to PA1 on the 2560
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// when the bit is clear, USB is connected
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PORTD |= 1;
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}
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// AVR parameters for ArduPilot MEGA v1.4 PPM Encoder (ATmega328P)
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#elif defined (__AVR_ATmega328P__) || defined (__AVR_ATmega328__)
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#define SERVO_DDR DDRD
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#define SERVO_PORT PORTD
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#define SERVO_INPUT PIND
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#define SERVO_INT_VECTOR PCINT2_vect
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#define SERVO_INT_MASK PCMSK2
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#define SERVO_INT_CLEAR_FLAG PCIF2
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#define SERVO_INT_ENABLE PCIE2
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#define SERVO_TIMER_CNT TCNT1
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#define PPM_DDR DDRB
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#define PPM_PORT PORTB
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#define PPM_OUTPUT_PIN PB2
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#define PPM_INT_VECTOR TIMER1_COMPB_vect
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#define PPM_COMPARE OCR1B
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#define PPM_COMPARE_FLAG COM1B0
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#define PPM_COMPARE_ENABLE OCIE1B
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#else
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#error NO SUPPORTED DEVICE FOUND! (ATmega16u2 / ATmega32u2 / ATmega328p)
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#endif
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// Used to indicate invalid SERVO input signals
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volatile uint8_t servo_input_errors = 0;
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// Used to indicate missing SERVO input signals
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volatile bool servo_input_missing = true;
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// Used to indicate if PPM generator is active
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volatile bool ppm_generator_active = false;
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// Used to indicate a brownout restart
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volatile bool brownout_reset = false;
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// ------------------------------------------------------------------------------
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// PPM GENERATOR START - TOGGLE ON COMPARE INTERRUPT ENABLE
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// ------------------------------------------------------------------------------
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void ppm_start( void )
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{
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// Prevent reenabling an already active PPM generator
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if( ppm_generator_active ) return;
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// Store interrupt status and register flags
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uint8_t SREG_tmp = SREG;
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// Stop interrupts
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cli();
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// Make sure initial output state is low
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PPM_PORT &= ~(1 << PPM_OUTPUT_PIN);
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// Wait for output pin to settle
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//_delay_us( 1 );
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// Set initial compare toggle to maximum (32ms) to give other parts of the system time to start
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SERVO_TIMER_CNT = 0;
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PPM_COMPARE = 0xFFFF;
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// Set toggle on compare output
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TCCR1A = (1 << PPM_COMPARE_FLAG);
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// Set TIMER1 8x prescaler
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TCCR1B = ( 1 << CS11 );
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// Enable output compare interrupt
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TIMSK1 |= (1 << PPM_COMPARE_ENABLE);
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// Indicate that PPM generator is active
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ppm_generator_active = true;
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// Restore interrupt status and register flags
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SREG = SREG_tmp;
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}
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// ------------------------------------------------------------------------------
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// PPM GENERATOR STOP - TOGGLE ON COMPARE INTERRUPT DISABLE
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// ------------------------------------------------------------------------------
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void ppm_stop( void )
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{
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// Store interrupt status and register flags
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uint8_t SREG_tmp = SREG;
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// Stop interrupts
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cli();
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// Disable output compare interrupt
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TIMSK1 &= ~(1 << PPM_COMPARE_ENABLE);
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// Reset TIMER1 registers
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TCCR1A = 0;
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TCCR1B = 0;
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// Indicate that PPM generator is not active
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ppm_generator_active = false;
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// Restore interrupt status and register flags
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SREG = SREG_tmp;
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}
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// ------------------------------------------------------------------------------
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// Watchdog Interrupt (interrupt only mode, no reset)
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// ------------------------------------------------------------------------------
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ISR( WDT_vect ) // If watchdog is triggered then enable missing signal flag and copy power on or failsafe positions
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{
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// Use failsafe values if PPM generator is active or if chip has been reset from a brown-out
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if ( ppm_generator_active || brownout_reset )
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{
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// Copy failsafe values to ppm[..]
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for ( uint8_t i = 0; i < PPM_ARRAY_MAX; i++ )
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{
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ppm[ i ] = failsafe_ppm[ i ];
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}
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}
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// If we are in PPM passtrough mode and a input signal has been detected, or if chip has been reset from a brown_out then start the PPM generator.
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if( ( servo_input_mode == PPM_PASSTROUGH_MODE && servo_input_missing == false ) || brownout_reset )
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{
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// Start PPM generator
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ppm_start();
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brownout_reset = false;
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}
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// Set missing receiver signal flag
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servo_input_missing = true;
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// Reset servo input error flag
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servo_input_errors = 0;
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}
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// ------------------------------------------------------------------------------
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// ------------------------------------------------------------------------------
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// SERVO/PPM INPUT - PIN CHANGE INTERRUPT
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// ------------------------------------------------------------------------------
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ISR( SERVO_INT_VECTOR )
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{
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// Servo pulse start timing
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static uint16_t servo_start[ SERVO_CHANNELS ] = { 0, 0, 0, 0, 0, 0, 0, 0 };
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// Servo input pin storage
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static uint8_t servo_pins_old = 0;
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// Used to store current servo input pins
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uint8_t servo_pins;
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// Read current servo pulse change time
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uint16_t servo_time = SERVO_TIMER_CNT;
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// ------------------------------------------------------------------------------
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// PPM passtrough mode ( signal passtrough from channel 1 to ppm output pin)
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// ------------------------------------------------------------------------------
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if( servo_input_mode == PPM_PASSTROUGH_MODE )
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{
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// Has watchdog timer failsafe started PPM generator? If so we need to stop it.
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if( ppm_generator_active )
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{
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// Stop PPM generator
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ppm_stop();
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}
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// PPM (channel 1) input pin is high
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if( SERVO_INPUT & 1 )
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{
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// Set PPM output pin high
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PPM_PORT |= (1 << PPM_OUTPUT_PIN);
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}
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// PPM (channel 1) input pin is low
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else
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{
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// Set PPM output pin low
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PPM_PORT &= ~(1 << PPM_OUTPUT_PIN);
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}
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// Reset Watchdog Timer
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wdt_reset();
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// Set servo input missing flag false to indicate that we have received servo input signals
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servo_input_missing = false;
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// Leave interrupt
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return;
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}
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// ------------------------------------------------------------------------------
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// SERVO PWM MODE
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// ------------------------------------------------------------------------------
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CHECK_PINS_START: // Start of servo input check
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// Store current servo input pins
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servo_pins = SERVO_INPUT;
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// Calculate servo input pin change mask
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uint8_t servo_change = servo_pins ^ servo_pins_old;
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// Set initial servo pin and channel
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uint8_t servo_pin = 1;
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uint8_t servo_channel = 0;
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CHECK_PINS_LOOP: // Input servo pin check loop
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// Check for pin change on current servo channel
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if( servo_change & servo_pin )
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{
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// High (raising edge)
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if( servo_pins & servo_pin )
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{
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servo_start[ servo_channel ] = servo_time;
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}
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else
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{
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// Get servo pulse width
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uint16_t servo_width = servo_time - servo_start[ servo_channel ] - PPM_PRE_PULSE;
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// Check that servo pulse signal is valid before sending to ppm encoder
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if( servo_width > PPM_SERVO_MAX ) goto CHECK_PINS_ERROR;
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if( servo_width < PPM_SERVO_MIN ) goto CHECK_PINS_ERROR;
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// Calculate servo channel position in ppm[..]
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uint8_t _ppm_channel = ( servo_channel << 1 ) + 1;
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#ifdef _AVERAGE_FILTER_
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// Average filter to smooth input jitter
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servo_width += ppm[ _ppm_channel ];
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servo_width >>= 1;
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#endif
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#ifdef _JITTER_FILTER_
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// 0.5us cut filter to remove input jitter
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int16_t ppm_tmp = ppm[ _ppm_channel ] - servo_width;
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if( ppm_tmp == 1 ) goto CHECK_PINS_NEXT;
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if( ppm_tmp == -1 ) goto CHECK_PINS_NEXT;
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#endif
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// Update ppm[..]
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ppm[ _ppm_channel ] = servo_width;
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}
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}
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CHECK_PINS_NEXT:
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// Select next servo pin
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servo_pin <<= 1;
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// Select next servo channel
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servo_channel++;
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// Check channel and process if needed
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if( servo_channel < SERVO_CHANNELS ) goto CHECK_PINS_LOOP;
|
|
|
|
goto CHECK_PINS_DONE;
|
|
|
|
CHECK_PINS_ERROR:
|
|
|
|
// Used to indicate invalid servo input signals
|
|
servo_input_errors++;
|
|
|
|
goto CHECK_PINS_NEXT;
|
|
|
|
// All servo input pins has now been processed
|
|
|
|
CHECK_PINS_DONE:
|
|
|
|
// Reset Watchdog Timer
|
|
wdt_reset();
|
|
|
|
// Set servo input missing flag false to indicate that we have received servo input signals
|
|
servo_input_missing = false;
|
|
|
|
// Store current servo input pins for next check
|
|
servo_pins_old = servo_pins;
|
|
|
|
// Start PPM generator if not already running
|
|
if( ppm_generator_active == false ) ppm_start();
|
|
|
|
//Has servo input changed while processing pins, if so we need to re-check pins
|
|
if( servo_pins != SERVO_INPUT ) goto CHECK_PINS_START;
|
|
|
|
// Clear interrupt event from already processed pin changes
|
|
PCIFR |= (1 << SERVO_INT_CLEAR_FLAG);
|
|
}
|
|
// ------------------------------------------------------------------------------
|
|
|
|
|
|
// ------------------------------------------------------------------------------
|
|
// PPM OUTPUT - TIMER1 COMPARE INTERRUPT
|
|
// ------------------------------------------------------------------------------
|
|
ISR( PPM_INT_VECTOR )
|
|
{
|
|
// Current active ppm channel
|
|
static uint8_t ppm_channel = PPM_ARRAY_MAX - 1;
|
|
|
|
// Update timing for next compare toggle
|
|
PPM_COMPARE += ppm[ ppm_channel ];
|
|
|
|
// Select the next ppm channel
|
|
if( ++ppm_channel >= PPM_ARRAY_MAX ) ppm_channel = 0;
|
|
|
|
}
|
|
// ------------------------------------------------------------------------------
|
|
|
|
// ------------------------------------------------------------------------------
|
|
// PPM READ - INTERRUPT SAFE PPM SERVO CHANNEL READ
|
|
// ------------------------------------------------------------------------------
|
|
uint16_t ppm_read_channel( uint8_t channel )
|
|
{
|
|
// Limit channel to valid value
|
|
uint8_t _channel = channel;
|
|
if( _channel == 0 ) _channel = 1;
|
|
if( _channel > SERVO_CHANNELS ) _channel = SERVO_CHANNELS;
|
|
|
|
// Calculate ppm[..] position
|
|
uint8_t ppm_index = ( _channel << 1 ) + 1;
|
|
|
|
// Read ppm[..] in a non blocking interrupt safe manner
|
|
uint16_t ppm_tmp = ppm[ ppm_index ];
|
|
while( ppm_tmp != ppm[ ppm_index ] ) ppm_tmp = ppm[ ppm_index ];
|
|
|
|
// Return as normal servo value
|
|
return ppm_tmp + PPM_PRE_PULSE;
|
|
}
|
|
// ------------------------------------------------------------------------------
|
|
|
|
// ------------------------------------------------------------------------------
|
|
// PPM ENCODER INIT
|
|
// ------------------------------------------------------------------------------
|
|
void ppm_encoder_init( void )
|
|
{
|
|
// ATmegaXXU2 only init code
|
|
// ------------------------------------------------------------------------------
|
|
#if defined (__AVR_ATmega16U2__) || defined (__AVR_ATmega32U2__)
|
|
// ------------------------------------------------------------------------------
|
|
// Reset Source checkings
|
|
// ------------------------------------------------------------------------------
|
|
if (MCUSR & 1) // Power-on Reset
|
|
{
|
|
MCUSR=0; // Clear MCU Status register
|
|
// custom code here
|
|
}
|
|
else if (MCUSR & 2) // External Reset
|
|
{
|
|
MCUSR=0; // Clear MCU Status register
|
|
// custom code here
|
|
}
|
|
else if (MCUSR & 4) // Brown-Out Reset
|
|
{
|
|
MCUSR=0; // Clear MCU Status register
|
|
brownout_reset=true;
|
|
}
|
|
else // Watchdog Reset
|
|
{
|
|
MCUSR=0; // Clear MCU Status register
|
|
// custom code here
|
|
}
|
|
|
|
// APM USB connection status UART MUX selector pin
|
|
// ------------------------------------------------------------------------------
|
|
USB_DDR |= (1 << USB_PIN); // Set USB pin to output
|
|
#endif
|
|
|
|
|
|
// USE JUMPER TO CHECK FOR PWM OR PPM PASSTROUGH MODE (channel 2&3 shorted)
|
|
// ------------------------------------------------------------------------------
|
|
if( servo_input_mode == JUMPER_SELECT_MODE )
|
|
{
|
|
// channel 3 status counter
|
|
uint8_t channel3_status = 0;
|
|
|
|
// Set channel 3 to input
|
|
SERVO_DDR &= ~(1 << 2);
|
|
|
|
// Enable channel 3 pullup
|
|
SERVO_PORT |= (1 << 2);
|
|
|
|
// Set channel 2 to output
|
|
SERVO_DDR |= (1 << 1);
|
|
|
|
// Set channel 2 output low
|
|
SERVO_PORT &= ~(1 << 1);
|
|
|
|
_delay_us (10);
|
|
|
|
// Increment channel3_status if channel 3 is set low by channel 2
|
|
if( ( SERVO_INPUT & (1 << 2) ) == 0 ) channel3_status++;
|
|
|
|
// Set channel 2 output high
|
|
SERVO_PORT |= (1 << 1);
|
|
|
|
_delay_us (10);
|
|
|
|
// Increment channel3_status if channel 3 is set high by channel 2
|
|
if( ( SERVO_INPUT & (1 << 2) ) != 0 ) channel3_status++;
|
|
|
|
// Set channel 2 output low
|
|
SERVO_PORT &= ~(1 << 1);
|
|
|
|
_delay_us (10);
|
|
|
|
// Increment channel3_status if channel 3 is set low by channel 2
|
|
if( ( SERVO_INPUT & (1 << 2) ) == 0 ) channel3_status++;
|
|
|
|
// Set servo input mode based on channel3_status
|
|
if( channel3_status == 3 ) servo_input_mode = PPM_PASSTROUGH_MODE;
|
|
else servo_input_mode = SERVO_PWM_MODE;
|
|
|
|
}
|
|
|
|
|
|
// SERVO/PPM INPUT PINS
|
|
// ------------------------------------------------------------------------------
|
|
// Set all servo input pins to inputs
|
|
SERVO_DDR = 0;
|
|
|
|
// Activate pullups on all input pins
|
|
SERVO_PORT |= 0xFF;
|
|
|
|
#if defined (__AVR_ATmega16U2__) || defined (__AVR_ATmega32U2__)
|
|
// on 32U2 set PD0 to be an output, and clear the bit. This tells
|
|
// the 2560 that USB is connected. The USB connection event fires
|
|
// later to set the right value
|
|
DDRD |= 1;
|
|
if (usb_connected) {
|
|
PORTD &= ~1;
|
|
} else {
|
|
PORTD |= 1;
|
|
}
|
|
#endif
|
|
|
|
// SERVO/PPM INPUT - PIN CHANGE INTERRUPT
|
|
// ------------------------------------------------------------------------------
|
|
if( servo_input_mode == SERVO_PWM_MODE )
|
|
{
|
|
// Set servo input interrupt pin mask to all 8 servo input channels
|
|
SERVO_INT_MASK = 0xFF;
|
|
}
|
|
|
|
if( servo_input_mode == PPM_PASSTROUGH_MODE )
|
|
{
|
|
// Set servo input interrupt pin mask to servo input channel 1
|
|
SERVO_INT_MASK = 0x01;
|
|
}
|
|
|
|
// Enable servo input interrupt
|
|
PCICR |= (1 << SERVO_INT_ENABLE);
|
|
|
|
|
|
// PPM OUTPUT PIN
|
|
// ------------------------------------------------------------------------------
|
|
// Set PPM pin to output
|
|
PPM_DDR |= (1 << PPM_OUTPUT_PIN);
|
|
|
|
// ------------------------------------------------------------------------------
|
|
// Enable watchdog interrupt mode
|
|
// ------------------------------------------------------------------------------
|
|
// Disable watchdog
|
|
wdt_disable();
|
|
// Reset watchdog timer
|
|
wdt_reset();
|
|
// Start timed watchdog setup sequence
|
|
WDTCSR |= (1<<WDCE) | (1<<WDE );
|
|
// Set 250 ms watchdog timeout and enable interrupt
|
|
WDTCSR = (1<<WDIE) | (1<<WDP2);
|
|
}
|
|
// ------------------------------------------------------------------------------
|
|
|
|
#endif // _PPM_ENCODER_H_
|
|
|