需要的硬件
一块arduino pro mini（推荐这个，比较小，当然如果你没有USB转转口的烧写工具买个ardunio nano板也是不错的，直接用USB线连接电脑就可以，用nano板要注意。它的usb口是大一点的mini usb口，而不是我们手机那种micro usb）
一个USB的串口刷写模块，用于更新arduino pro mini，用nano板的请无视
直接上图和代码
代码直接下载
在arduino的ide里面代码：
先建立一个名为 buzz_8pwm_to_ppm328的目录，然后在目录下建立两个文本文件 ：
buzz_8pwm_to_ppm328.ino
PPM_Encoder.h
用arduino的IDE打开buzz_8pwm_to_ppm328.ino 烧写进板子就可以了
两个文件的内容如下
buzz_8pwm_to_ppm328.ino
#include "Arduino.h" #include "ppm_encoder.h" #include <util/delay.h> #include <avr/io.h>#define ERROR_THRESHOLD 2 // Number of servo input errors before alerting #define ERROR_DETECTION_WINDOW 3000 * LOOP_TIMER_10MS // Detection window for error detection (default to 30s) #define ERROR_CONDITION_DELAY 500 * LOOP_TIMER_10MS // Servo error condition LED delay (LED blinking duration)#define PASSTHROUGH_MODE_ENABLED // Comment this line to remove CH8 radio passthrough mode support (hardware failsafe for Arduplane) #define PASSTHROUGH_CHANNEL 8 * 2 // Channel for passthrough mode selection #define PASSTHROUGH_CHANNEL_OFF_US ONE_US * 1600 - PPM_PRE_PULSE // Passthrough off threshold #define PASSTHROUGH_CHANNEL_ON_US ONE_US * 1800 - PPM_PRE_PULSE // Passthrough on threshold#define THROTTLE_CHANNEL 3 * 2 // Throttle Channel #define THROTTLE_CHANNEL_LED_TOGGLE_US ONE_US * 1200 - PPM_PRE_PULSE // Throttle Channel Led toggle threshold #define LED_LOW_BLINKING_RATE 125 * LOOP_TIMER_10MS // Led blink rate for low throttle position (half period)// Timers#define TIMER0_10MS 156 // Timer0 ticks for 10 ms duration #define TIMER1_10MS 20000 // Timer1 ticks for 10 ms duration #define TIMER2_100MS 1562 // Timer2 ticks for 100 ms duration #define LOOP_TIMER_10MS 10 // Loop timer ticks for 10 ms duration// LED Code#define SPACE_SHORT_DURATION 40 * LOOP_TIMER_10MS // Space after short symbol #define SPACE_LONG_DURATION 75 * LOOP_TIMER_10MS // Space after long symbol #define SYMBOL_SHORT_DURATION 20 * LOOP_TIMER_10MS // Short symbol duration #define SYMBOL_LONG_DURATION 100 * LOOP_TIMER_10MS // Long symbol duration #define INTER_CODE_DURATION 150 * LOOP_TIMER_10MS // Inter code duration#define INTER_CODE 0 // Symbols value for coding #define SHORT_SYMBOL 1 #define LONG_SYMBOL 2 #define SHORT_SPACE 3 #define LONG_SPACE 4 #define LOOP 5// ------------------------------------------------------------------------------------------------------------------------------------------------------------ // PPM ENCODER INIT AND AUXILIARY TASKS // ------------------------------------------------------------------------------------------------------------------------------------------------------------// ------------------------------------------------------------------------------------------------------------------------------------------------------------// LOCAL VARIABLES// ------------------------------------------------------------------------------------------------------------------------------------------------------------bool localinit = true; // We are inside init sequencebool mux_passthrough = false; // Mux passthrough mode status Flag : passthrough is offuint16_t led_acceleration; // Led acceleration based on throttle stick positionbool servo_error_condition = false; // Servo signal error conditionstatic uint16_t servo_error_detection_timer=0; // Servo error detection timerstatic uint16_t servo_error_condition_timer=0; // Servo error condition timerstatic uint16_t blink_led_timer = 0; // Blink led timer #ifdef PASSTHROUGH_MODE_ENABLEDstatic uint8_t mux_timer = 0; // Mux timerstatic uint8_t mux_counter = 0; // Mux counterstatic int8_t mux_check = 0;static uint16_t mux_ppm = 500;#endifstatic uint16_t led_code_timer = 0; // Blink Code Timerstatic uint8_t led_code_symbol = 0; // Blink Code current symbol// ------------------------------------------------------------------------------------------------------------------------------------------------------------// LOCAL FUNCTIONS// ------------------------------------------------------------------------------------------------------------------------------------------------------------// ------------------------------------------------------------------------------// Led blinking (non blocking) function// ------------------------------------------------------------------------------ uint8_t blink_led ( uint16_t half_period ) // ( half_period max = 65 s ) {blink_led_timer++;if ( blink_led_timer < half_period ) // If half period has not been reached {return 0; // Exit timer function and return 0 }else // half period reached - LED Toggle {PPM_PORT ^= ( 1 << PB0 ); // Toggle status LEDblink_led_timer = 0; // Blink led timer resetreturn 1; // half period reached - Exit timer function and return 1 }}// ------------------------------------------------------------------------------// Led code (non blocking) function// ------------------------------------------------------------------------------void blink_code_led ( uint8_t code ){const uint8_t coding[2][14] = {// PPM_PASSTROUGH_MODE { INTER_CODE, LONG_SYMBOL, LONG_SPACE, SHORT_SYMBOL, SHORT_SPACE, SHORT_SYMBOL, LOOP }, // JETI_MODE { INTER_CODE, LONG_SYMBOL, LONG_SPACE, SHORT_SYMBOL, SHORT_SPACE, SHORT_SYMBOL, SHORT_SPACE, SHORT_SYMBOL,LOOP }};led_code_timer++; switch ( coding [ code - 2 ] [ led_code_symbol ] ){case INTER_CODE:if ( led_code_timer < ( INTER_CODE_DURATION ) ) return;else PPM_PORT |= ( 1 << PB0 ); // Enable status LEDbreak;case LONG_SYMBOL: // Long symbolif ( led_code_timer < ( SYMBOL_LONG_DURATION ) ) return;else PPM_PORT &= ~( 1 << PB0 ); // Disable status LEDbreak;case SHORT_SYMBOL: // Short symbolif ( led_code_timer < ( SYMBOL_SHORT_DURATION ) ) return;else PPM_PORT &= ~( 1 << PB0 ); // Disable status LEDbreak;case SHORT_SPACE: // Short spaceif ( led_code_timer < ( SPACE_SHORT_DURATION ) ) return;else PPM_PORT |= ( 1 << PB0 ); // Enable status LEDbreak;case LONG_SPACE: // Long spaceif ( led_code_timer < ( SPACE_LONG_DURATION ) ) return;else PPM_PORT |= ( 1 << PB0 ); // Enable status LEDbreak;case LOOP: // Loop to code startled_code_symbol = 0;return;break;}led_code_timer = 0; // Code led timer resetled_code_symbol++; // Next symbolreturn; // LED code function return }// ------------------------------------------------------------------------------// ppm reading helper - interrupt safe and non blocking function// ------------------------------------------------------------------------------ uint16_t ppm_read( uint8_t channel ){uint16_t ppm_tmp = ppm[ channel ];while( ppm_tmp != ppm[ channel ] ) ppm_tmp = ppm[ channel ];return ppm_tmp;}// ------------------------------------------------------------------------------------------------------------------------------------------------------------// INITIALISATION CODE// ------------------------------------------------------------------------------------------------------------------------------------------------------------void setup() {// ------------------------------------------------------------------------------ // 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 registerbrownout_reset=true;}else // Watchdog Reset {MCUSR=0; // Clear MCU Status register// custom code here }// ------------------------------------------------------------------------------// Servo input and PPM generator init// ------------------------------------------------------------------------------ ppm_encoder_init();// ------------------------------------------------------------------------------// Outputs init// ------------------------------------------------------------------------------PPM_DDR |= ( 1 << PB0 ); // Set LED pin (PB0) to outputPPM_DDR |= ( 1 << PB1 ); // Set MUX pin (PB1) to outputPPM_DDR |= ( 1 << PPM_OUTPUT_PIN ); // Set PPM pin (PPM_OUTPUT_PIN, OC1B) to output// ------------------------------------------------------------------------------ // Timer0 init (normal mode) used for LED control and custom code// ------------------------------------------------------------------------------TCCR0A = 0x00; // Clock source: System ClockTCCR0B = 0x05; // Set 1024x prescaler - Clock value: 15.625 kHz - 16 ms max timeTCNT0 = 0x00;OCR0A = 0x00; // OC0x outputs: DisconnectedOCR0B = 0x00;TIMSK0 = 0x00; // Timer 1 interrupt disable// ------------------------------------------------------------------------------// Enable global interrupt// ------------------------------------------------------------------------------sei(); // Enable Global interrupt flag// ------------------------------------------------------------------------------// Disable radio passthrough (mux chip A/B control)// ------------------------------------------------------------------------------PPM_PORT |= ( 1 << PB1 ); // Set PIN B1 to disable Radio passthrough (mux) }void loop() {// ------------------------------------------------------------------------------------------------------------------------------------------------------------// AUXILIARY TASKS// ------------------------------------------------------------------------------------------------------------------------------------------------------------PWM_LOOP: // SERVO_PWM_MODEwhile( 1 ){_delay_us (950); // Slow down while loop } // PWM Loop end } // main lopo function end
PPM_Encoder.h
// ------------------------------------------------------------- #ifndef _PPM_ENCODER_H_ #define _PPM_ENCODER_H_#include <avr/io.h>// ------------------------------------------------------------- #include <avr/interrupt.h> #include <avr/wdt.h> #include <util/delay.h>// ------------------------------------------------------------- // SERVO INPUT FILTERS // ------------------------------------------------------------- // Using both filters is not recommended and may reduce servo input resolution// #define _AVERAGE_FILTER_ // Average filter to smooth servo input capture jitter // #define _JITTER_FILTER_ // Cut filter to remove 0,5us servo input capture jitter // ------------------------------------------------------------- #ifndef F_CPU #define F_CPU 16000000UL #endif#ifndef true #define true 1 #endif#ifndef false #define false 0 #endif//#ifndef bool //#define bool boolean //#endif // 328 does not define PBX but defines an equivalent as PORTBX, comment these lines out if you already have a PB2 defined. #define PB2 PORTB2 #define PB1 PORTB1 #define PB0 PORTB0 // ------------------------------------------------------------- // SERVO INPUT MODE - !EXPERIMENTAL! // -------------------------------------------------------------#define SERVO_PWM_MODE 1 // Normal 8 channel servo (pwm) input// Servo input mode (jumper (default), pwm, ppm, jeti or spektrum) volatile uint8_t servo_input_mode = SERVO_PWM_MODE; // -------------------------------------------------------------// Number of Timer1 ticks in one microsecond #define ONE_US F_CPU / 8 / 1000 / 1000// 400us PPM pre pulse #define PPM_PRE_PULSE ONE_US * 400// ------------------------------------------------------------- // SERVO LIMIT VALUES // -------------------------------------------------------------// Servo minimum position #define PPM_SERVO_MIN ONE_US * 900 - PPM_PRE_PULSE// Servo center position #define PPM_SERVO_CENTER ONE_US * 1500 - PPM_PRE_PULSE// Servo maximum position #define PPM_SERVO_MAX ONE_US * 2100 - PPM_PRE_PULSE// Throttle default at power on #define PPM_THROTTLE_DEFAULT ONE_US * 1100 - PPM_PRE_PULSE// Throttle during failsafe #define PPM_THROTTLE_FAILSAFE ONE_US * 900 - PPM_PRE_PULSE// CH5 power on values (mode selection channel) //#define PPM_CH5_MODE_4 ONE_US * 1555 - PPM_PRE_PULSE// -------------------------------------------------------------// Number of servo input channels #define SERVO_CHANNELS 8// PPM period 18.5ms - 26.5ms (54hz - 37Hz) #define PPM_PERIOD ONE_US * ( 22500 - ( 8 * 1500 ) )// Size of ppm[..] data array ( servo channels * 2 + 2) #define PPM_ARRAY_MAX 18// Data array for storing ppm (8 channels) pulse widths. volatile uint16_t ppm[ PPM_ARRAY_MAX ] = {PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 1 PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 2 PPM_PRE_PULSE,PPM_THROTTLE_DEFAULT, // Channel 3 (throttle) PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 4 PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 5 PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 6 PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 7 PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 8 PPM_PRE_PULSE,PPM_PERIOD };// ------------------------------------------------------------- // SERVO FAILSAFE VALUES // ------------------------------------------------------------- const uint16_t failsafe_ppm[ PPM_ARRAY_MAX ] = {PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 1 PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 2 PPM_PRE_PULSE,PPM_THROTTLE_FAILSAFE, // Channel 3 (throttle) PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 4 PPM_PRE_PULSE,PPM_SERVO_MAX, // Channel 5 PPM_PRE_PULSE,PPM_SERVO_MAX, // Channel 6 PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 7 PPM_PRE_PULSE,PPM_SERVO_CENTER, // Channel 8 PPM_PRE_PULSE,PPM_PERIOD }; // -------------------------------------------------------------// AVR parameters for ArduPilot MEGA v1.4 PPM Encoder (ATmega328P) #if defined (__AVR_ATmega328P__) || defined (__AVR_ATmega328__)#define SERVO_DDR DDRD #define SERVO_PORT PORTD #define SERVO_INPUT PIND // PCIE2 PC Interrupt enable 2 is for Arduino Pins (D0-D7), also called PORTD. #define SERVO_INT_VECTOR PCINT2_vect#define SERVO_INT_MASK PCMSK2 #define SERVO_INT_CLEAR_FLAG PCIF2 #define SERVO_INT_ENABLE PCIE2 #define SERVO_TIMER_CNT TCNT1#define PPM_DDR DDRB #define PPM_PORT PORTB #define PPM_OUTPUT_PIN PB2 #define PPM_INT_VECTOR TIMER1_COMPB_vect #define PPM_COMPARE OCR1B #define PPM_COMPARE_FLAG COM1B0 #define PPM_COMPARE_ENABLE OCIE1B#else #error NO SUPPORTED DEVICE FOUND! ( ATmega328/p) #endif// Used to indicate invalid SERVO input signals //volatile uint8_t servo_input_errors = 0;// Used to indicate missing SERVO input signals volatile bool servo_input_missing = true;// Used to indicate if PPM generator is active volatile bool ppm_generator_active = false;// Used to indicate a brownout restart volatile bool brownout_reset = false;// ------------------------------------------------------------------------------ // PPM GENERATOR START - TOGGLE ON COMPARE INTERRUPT ENABLE // ------------------------------------------------------------------------------ // this starts OUTGOING PPM stream on PPM_PORT (PORTB, Arduino D8-D13) at PPM_OUTPUT_PIN (PB2, arduino pin D10) void ppm_start( void ) {// Prevent reenabling an already active PPM generatorif( ppm_generator_active ) return;// Store interrupt status and register flagsuint8_t SREG_tmp = SREG;// Stop interrupts cli();// Make sure initial output state is lowPPM_PORT &= ~(1 << PPM_OUTPUT_PIN);// Wait for output pin to settle//_delay_us( 1 );// Set initial compare toggle to maximum (32ms) to give other parts of the system time to startSERVO_TIMER_CNT = 0;PPM_COMPARE = 0xFFFF;// Set toggle on compare outputTCCR1A = (1 << PPM_COMPARE_FLAG);// Set TIMER1 8x prescalerTCCR1B = ( 1 << CS11 );// Enable output compare interruptTIMSK1 |= (1 << PPM_COMPARE_ENABLE);// Indicate that PPM generator is activeppm_generator_active = true;// Restore interrupt status and register flagsSREG = SREG_tmp;}// ------------------------------------------------------------------------------ // PPM GENERATOR STOP - TOGGLE ON COMPARE INTERRUPT DISABLE // ------------------------------------------------------------------------------ void ppm_stop( void ) {// Store interrupt status and register flagsuint8_t SREG_tmp = SREG;// Stop interrupts cli();// Disable output compare interruptTIMSK1 &= ~(1 << PPM_COMPARE_ENABLE);// Reset TIMER1 registersTCCR1A = 0;TCCR1B = 0;// Indicate that PPM generator is not activeppm_generator_active = false;// Restore interrupt status and register flagsSREG = SREG_tmp;}// ------------------------------------------------------------------------------ // Watchdog Interrupt (interrupt only mode, no reset) // ------------------------------------------------------------------------------ ISR( WDT_vect ) // If watchdog is triggered then enable missing signal flag and copy power on or failsafe positions {// Use failsafe values if PPM generator is active or if chip has been reset from a brown-outif ( ppm_generator_active || brownout_reset ){// Copy failsafe values to ppm[..]for ( uint8_t i = 0; i < PPM_ARRAY_MAX; i++ ){ppm[ i ] = failsafe_ppm[ i ];}}// Set missing receiver signal flagservo_input_missing = true;// Reset servo input error flag//servo_input_errors = 0; } // ------------------------------------------------------------------------------// ------------------------------------------------------------------------------ // SERVO/PPM INPUT - PIN CHANGE INTERRUPT, for any Arduino pin D0 -> D7 // ------------------------------------------------------------------------------ ISR( SERVO_INT_VECTOR ) {// Servo pulse start timingstatic uint16_t servo_start[ SERVO_CHANNELS ] = { 0, 0, 0, 0, 0, 0, 0, 0 };// Missing throttle signal failsafestatic uint8_t throttle_timeout = 0;// Servo input pin storage static uint8_t servo_pins_old = 0;// Used to store current servo input pins uint8_t servo_pins;// Read current servo pulse change timeuint16_t servo_time = SERVO_TIMER_CNT;// ------------------------------------------------------------------------------// SERVO PWM MODE// ------------------------------------------------------------------------------ CHECK_PINS_START: // Start of servo input check// Store current servo input pinsservo_pins = SERVO_INPUT;// Calculate servo input pin change maskuint8_t servo_change = servo_pins ^ servo_pins_old;// Set initial servo pin and channeluint8_t servo_pin = 1;uint8_t servo_channel = 0;CHECK_PINS_LOOP: // Input servo pin check loop// Check for pin change on current servo channelif( servo_change & servo_pin ){ // if (( servo_pin == 1 ) && ( ppm_generator_active = false) ) ppm_start(); // if (( servo_pin == 8 ) && ( ppm_generator_active = true) ) ppm_stop(); // High (raising edge)if( servo_pins & servo_pin ){servo_start[ servo_channel ] = servo_time;}else{// Get servo pulse widthuint16_t servo_width = servo_time - servo_start[ servo_channel ] - PPM_PRE_PULSE;// Calculate servo channel position in ppm[..]uint8_t _ppm_channel = ( servo_channel << 1 ) + 1;// Check that servo pulse signal is valid before sending to ppm encoderif( servo_width > PPM_SERVO_MAX ) goto CHECK_PINS_ERROR;if( servo_width < PPM_SERVO_MIN ) goto CHECK_PINS_ERROR;goto CHECK_PINS_NOERROR;CHECK_PINS_ERROR:// on width input error, use defailt/failsave value, OR previous value // choose the error handling type here!#define FAILHOLD 1#ifdef FAILCENTREservo_width = failsafe_ppm[ _ppm_channel ]; // failsafe defaults, most channels centred, throttle lowered. #endif#ifdef FAILHOLD servo_width = ppm[ _ppm_channel ]; // all channels hold their previous position! #endifCHECK_PINS_NOERROR://Reset throttle failsafe timeoutif( _ppm_channel == 5 ) throttle_timeout = 0;#ifdef _AVERAGE_FILTER_// Average filter to smooth input jitterservo_width += ppm[ _ppm_channel ];servo_width >>= 1;#endif#ifdef _JITTER_FILTER_// 0.5us cut filter to remove input jitterint16_t ppm_tmp = ppm[ _ppm_channel ] - servo_width;if( ppm_tmp == 1 ) goto CHECK_PINS_NEXT;if( ppm_tmp == -1 ) goto CHECK_PINS_NEXT;#endif// Update ppm[..]ppm[ _ppm_channel ] = servo_width;}}CHECK_PINS_NEXT:// Select next servo pinservo_pin <<= 1;// Select next servo channelservo_channel++;// Check channel and process if neededif( servo_channel < SERVO_CHANNELS ) goto CHECK_PINS_LOOP;goto CHECK_PINS_DONE;// 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 signalsservo_input_missing = false;// Store current servo input pins for next checkservo_pins_old = servo_pins;// Start PPM generator if not already runningif( ppm_generator_active == false ) ppm_start();// Throttle failsafeif( throttle_timeout++ >= 128 ){// Reset throttle timeoutthrottle_timeout = 0;// Set throttle failsafe valueppm[ 5 ] = PPM_THROTTLE_FAILSAFE;}//Has servo input changed while processing pins, if so we need to re-check pinsif( servo_pins != SERVO_INPUT ) goto CHECK_PINS_START;// Clear interrupt event from already processed pin changesPCIFR |= (1 << SERVO_INT_CLEAR_FLAG); } // ------------------------------------------------------------------------------// ------------------------------------------------------------------------------ // PPM OUTPUT - TIMER1 COMPARE INTERRUPT // ------------------------------------------------------------------------------ ISR( PPM_INT_VECTOR ) {// Current active ppm channelstatic uint8_t ppm_channel = PPM_ARRAY_MAX - 1;// Update timing for next compare togglePPM_COMPARE += ppm[ ppm_channel ];// Select the next ppm channelif( ++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 valueuint8_t _channel = channel;if( _channel == 0 ) _channel = 1;if( _channel > SERVO_CHANNELS ) _channel = SERVO_CHANNELS;// Calculate ppm[..] positionuint8_t ppm_index = ( _channel << 1 ) + 1;// Read ppm[..] in a non blocking interrupt safe manneruint16_t ppm_tmp = ppm[ ppm_index ];while( ppm_tmp != ppm[ ppm_index ] ) ppm_tmp = ppm[ ppm_index ];// Return as normal servo valuereturn ppm_tmp + PPM_PRE_PULSE; } */ // ------------------------------------------------------------------------------// ------------------------------------------------------------------------------ // PPM ENCODER INIT // ------------------------------------------------------------------------------ void ppm_encoder_init( void ) {// SERVO/PPM INPUT PINS// ------------------------------------------------------------------------------// Set all servo input pins to inputsSERVO_DDR = 0;// Activate pullups on all input pinsSERVO_PORT |= 0xFF;// SERVO/PPM INPUT - PIN CHANGE INTERRUPT// ------------------------------------------------------------------------------if( servo_input_mode == SERVO_PWM_MODE ){// Set servo input interrupt pin mask to all 8 servo input channelsSERVO_INT_MASK = 0xFF;}// Enable servo input interruptPCICR |= (1 << SERVO_INT_ENABLE);// PPM OUTPUT PIN// ------------------------------------------------------------------------------// Set PPM pin to outputPPM_DDR |= (1 << PPM_OUTPUT_PIN);// ------------------------------------------------------------------------------// Enable watchdog interrupt mode// ------------------------------------------------------------------------------// Disable watchdog wdt_disable();// Reset watchdog timer wdt_reset();// Start timed watchdog setup sequenceWDTCSR |= (1<<WDCE) | (1<<WDE );// Set 250 ms watchdog timeout and enable interruptWDTCSR = (1<<WDIE) | (1<<WDP2);} // ------------------------------------------------------------------------------#endif // _PPM_ENCODER_H_
