WebSVN - Projects - Blame - Rev 1398 - /RC-Expander/branches/MX16s_10Ch

Rev	Author	Line No.	Line
1398	-	1	/*------------------------------------------------------------------------------
		2	Ident : main.c
		3	Project : MX16s 8->10 ppm channel expander
		4	Author : lakeroe
		5	Description : main module
		6	Copyright (c) : 12.2011 lakeroe
		7	Original code and idea : Jacques Wanders
		8	http://forum.mikrokopter.de/topic-4405.html
		9	http://forum.mikrokopter.de/topic-4556.html
		10	----------------------------------------------------------------------------
		11	Release : v1.0 initial release
		12	Date : 25-12-2011
		13	----------------------------------------------------------------------------
		14	The use of this project (hardware, software, binary files, sources and
		15	documentation) is only permittet for non-commercial use
		16	(directly or indirectly)
		17	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
		18	AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
		19	IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
		20	ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
		21	LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
		22	CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
		23	SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
		24	INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
		25	CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
		26	ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
		27	POSSIBILITY OF SUCH DAMAGE.
		28	------------------------------------------------------------------------------*/
		29
		30	#include <avr/io.h>
		31	#include <avr/interrupt.h>
		32	#include "main.h"
		33
		34	enum
		35	{
		36	stPPM_SYNC,
		37	stPPM_SYNC_WAIT,
		38	stPPM_CHANNEL_START,
		39	stPPM_CHANNEL_DATA,
		40	stPPM_CHANNEL_9_DATA,
		41	stPPM_CHANNEL_10_START,
		42	stPPM_CHANNEL_10_DATA,
		43	stPPM_FINISH_PULSE,
		44	stPPM_FRAME_END
		45	};
		46
		47	unsigned char channel_number = 0;
		48	unsigned char ppm_state = stPPM_SYNC;
		49
		50	// timer1_capture_interrupt (void)
		51	// Synchronise PPM frame and copy input events to PPM_OUT, start mixing Ch9,10 data when detect start pulse of Ch9
		52	ISR (TIM1_CAPT_vect)
		53	{
		54	cli (); // disable interrupts
		55	unsigned int data;
		56
		57	switch (ppm_state)
		58	{
		59	case stPPM_SYNC: // detect rising edge pulse
		60	data = ICR1; // get timer value after input capture
		61	SET_COUNTER_TO_ZERO;
		62	FALLING_EDGE_TRIGGER;
		63	if(data >= MIN_SYNC_TIME && data <= MAX_SYNC_TIME) // valid sync trigger
		64	{
		65	SET_PPM_OUT_HIGH;
		66	ppm_state = stPPM_CHANNEL_DATA; // next state: get data
		67	channel_number = 0;
		68	}
		69	else // trigger but not a valid sync time
		70	{
		71	SET_PPM_OUT_LOW;
		72	ppm_state = stPPM_SYNC_WAIT; // next state: wait for next sync event
		73	}
		74	break;
		75
		76	case stPPM_SYNC_WAIT: // detect falling edge pulse
		77	SET_PPM_OUT_LOW; // not nessecery, output should already be low
		78	SET_COUNTER_TO_ZERO;
		79	SET_CAPTURE_COUNTER_TO_ZERO;
		80	RISING_EDGE_TRIGGER;
		81	ppm_state = stPPM_SYNC; // next state: try again for new sync
		82	break;
		83
		84	case stPPM_CHANNEL_START: // detect rising edge pulse
		85	SET_COUNTER_TO_ZERO;
		86	SET_PPM_OUT_HIGH;
		87	FALLING_EDGE_TRIGGER;
		88	channel_number++; // prepare for next MX16s channel clock
		89	if(channel_number>7) // all eight channels read
		90	{
		91	SET_COUNTER_TO_ZERO;
		92	SET_PPM_OUT_HIGH;
		93	SET_TIMER_TO_COMPA_CTC;
		94	DISABLE_INPUT_CAPTURE;
		95	ENABLE_OUTPUT_COMPARE;
		96	OCR1A = START_PULSE; // startpulse length 0.4ms
		97	TRIGGER_INPUT_COMPARE_INTERRUPT;
		98	ppm_state = stPPM_CHANNEL_9_DATA; // 9th. channel but now self created
		99	channel_number = 0;
		100	}
		101	else
		102	ppm_state = stPPM_CHANNEL_DATA;
		103	break;
		104
		105	case stPPM_CHANNEL_DATA: // detect falling edge pulse
		106	SET_COUNTER_TO_ZERO;
		107	SET_PPM_OUT_LOW;
		108	RISING_EDGE_TRIGGER;
		109	ppm_state = stPPM_CHANNEL_START; // wait for next channel rising edge pulse
		110	break;
		111
		112	default:
		113	SET_PPM_OUT_LOW; // not nessecery, output should already be low
		114	SET_COUNTER_TO_ZERO;
		115	SET_CAPTURE_COUNTER_TO_ZERO;
		116	RISING_EDGE_TRIGGER;
		117	ppm_state = stPPM_SYNC; // next state: try again for new sync
		118	break;
		119	}
		120	sei ();
		121	}
		122
		123	// timer1_compare_interrupt (void)
		124	// Mixing channel 9,10 data into ppm out, start input capture for frame synchronisation
		125	ISR (TIM1_COMPA_vect)
		126	{
		127	cli ();
		128	switch (ppm_state)
		129	{
		130	case stPPM_CHANNEL_9_DATA:
		131	SET_PPM_OUT_LOW;
		132	SET_COUNTER_TO_ZERO;
		133	if (PINA & (1 << CHANNEL_9)) // Channel 9 on/off
		134	OCR1A = PPM_PULSE_MAX - START_PULSE;
		135	else
		136	OCR1A = PPM_PULSE_MIN - START_PULSE;
		137	// set OCR1A between [PPM_PULSE_MIN-START_PULSE] and [PPM_PULSE_MAX-START_PULSE] for transmitting analog value
		138	ppm_state = stPPM_CHANNEL_10_START; // next State
		139	break;
		140
		141	case stPPM_CHANNEL_10_START:
		142	SET_PPM_OUT_HIGH;
		143	SET_COUNTER_TO_ZERO;
		144	OCR1A = START_PULSE; // startpulse length 0.4ms
		145	ppm_state = stPPM_CHANNEL_10_DATA; // next State
		146	break;
		147
		148	case stPPM_CHANNEL_10_DATA:
		149	SET_PPM_OUT_LOW;
		150	SET_COUNTER_TO_ZERO;
		151	if (PINA & (1 << CHANNEL_10)) // Channel 10 on/off
		152	OCR1A = PPM_PULSE_MAX - START_PULSE;
		153	else
		154	OCR1A = PPM_PULSE_MIN - START_PULSE;
		155	// set OCR1A between [PPM_PULSE_MIN-START_PULSE] and [PPM_PULSE_MAX-START_PULSE] for transmitting analog value
		156	ppm_state = stPPM_FINISH_PULSE; // next State
		157	break;
		158
		159	case stPPM_FINISH_PULSE: // create last pulse
		160	SET_PPM_OUT_HIGH;
		161	SET_COUNTER_TO_ZERO;
		162	OCR1A = START_PULSE; // startpulse length 0.4ms
		163	ppm_state = stPPM_FRAME_END; // next State
		164	break;
		165
		166	case stPPM_FRAME_END:
		167	default:
		168	SET_PPM_OUT_LOW;
		169	RISING_EDGE_TRIGGER;
		170	DISABLE_OUTPUT_COMPARE;
		171	ENABLE_INPUT_CAPTURE;
		172	SET_TIMER_TO_COMPA_CTC;
		173	SET_COUNTER_TO_ZERO;
		174	SET_COMPARE_COUNTER_TO_ZERO;
		175	SET_CAPTURE_COUNTER_TO_ZERO;
		176	ppm_state = stPPM_SYNC; // next State
		177	TRIGGER_INPUT_CAPTURE_INTERRUPT;
		178	break;
		179	}
		180	sei ();
		181	}
		182
		183	int main (void)
		184	{
		185	cli (); // disable interrupts
		186
		187	DDRA &= ~(1<<PPM_IN); // set Input Capture Pin as input
		188	PORTA \|= (1<<PPM_IN); // enable pullup
		189
		190	DDRB \|= (1<<PPM_OUT_PIN); // configure PPM_OUT pin as output
		191	SET_PPM_OUT_LOW; // set low
		192
		193	DDRA &= ~(1 << CHANNEL_9); // Channel 9 (Pin 10) input
		194	PORTA \|= (1 << CHANNEL_9); // enable pullup
		195
		196	DDRA &= ~(1 << CHANNEL_10); // Channel 10 (Pin 9) input
		197	PORTA \|= (1 << CHANNEL_10); // enable pullup
		198
		199	TCCR1A = ((0<<WGM11)\|(0<<WGM10)); // CTC mode
		200	TCCR1B = ((0<<WGM13)\|(1<<WGM12)\|(0<<CS12)\|(1<<CS11)\|(0<<CS10)); // CTC mode for COMPA, prescaler 8 / 8MHz => [1.0us]
		201
		202	CLEAR_INPUT_CAPTURE_INTERRUPT_FLAG; // reset ICF flag
		203	SET_COUNTER_TO_ZERO;
		204	SET_COMPARE_COUNTER_TO_ZERO;
		205	ENABLE_INPUT_CAPTURE;
		206	DISABLE_OUTPUT_COMPARE;
		207	RISING_EDGE_TRIGGER;
		208
		209	sei (); // enable interrupts
		210
		211	while(1);
		212	}

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