WebSVN - Projects - Blame - Rev 104 - /RC-Expander/trunk/main.c

Rev	Author	Line No.	Line
104	ingob	1	/*------------------------------------------------------------------------------
		2
		3	Ident : main.c
		4	Project : MX12 2 (3) ppm channel expander
		5	Author : Jacques Wanders
		6	Description : main module
		7	Copyright (c): 05.2008 Jacques Wanders
		8	modified : 05.2008 Heinrich Fischer for use with WinAVR
		9
		10	----------------------------------------------------------------------------
		11	Release : v1.0 initial release
		12	Date : 13-05-2008
		13	----------------------------------------------------------------------------
		14	Release : v1.1
		15	Date : 13-05-2008
		16	Notes : Added Channel 9
		17	----------------------------------------------------------------------------
		18	Release : v1.2
		19	Date : 22-05-2008
		20	Notes : Modified time definitions for FORCE_LOW_END_FRAME
		21	and MIN_SYNC_TIME to avoid lost pulse groups
		22	----------------------------------------------------------------------------
		23
		24	The use of this project (hardware, software, binary files, sources and
		25	documentation) is only permittet for non-commercial use
		26	(directly or indirectly)
		27	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
		28	AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
		29	IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
		30	ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
		31	LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
		32	CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
		33	SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
		34	INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
		35	CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
		36	ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
		37	POSSIBILITY OF SUCH DAMAGE.
		38
		39	------------------------------------------------------------------------------*/
		40
		41	#define ENABLE_BIT_DEFINITIONS
		42	//#include <ioavr.h>
		43	//#include <inavr.h>
		44	#include <avr/io.h>
		45	#include <avr/interrupt.h>
		46	#include "main.h"
		47
		48
		49	enum{
		50	stPPM_SYNC,
		51	stPPM_SYNC_WAIT,
		52	stPPM_CHANNEL_START,
		53	stPPM_CHANNEL_DATA,
		54	stPPM_CHANNEL_7_DATA_TRIGGER,
		55	stPPM_CHANNEL_7_DATA,
		56	stPPM_CHANNEL_8_START,
		57	stPPM_CHANNEL_8_DATA,
		58	stPPM_CHANNEL_9_START,
		59	stPPM_CHANNEL_9_DATA,
		60	stPPM_FINISH_PULSE,
		61	stPPM_FINISH_FRAME,
		62	stPPM_FRAME_END,
		63	};
		64
		65	unsigned char channel_number = 0;
		66	unsigned char ppm_state = stPPM_SYNC;
		67	unsigned char adc_channel = 0;
		68	volatile unsigned int channel_7 = 0xffff; // set to max. for testing if conversion is valid
		69	volatile unsigned int channel_8 = 0xffff; // set to max. for testing if conversion is valid
		70	volatile unsigned int channel_9 = 0xffff; // set to max. for testing if conversion is valid
		71
		72
		73	/*------------------------------------------------------------------------------
		74
		75	function : init_pin(void)
		76	purpose : Initialise I/O pins
		77
		78	*----------------------------------------------------------------------------/
		79	void init_pin(void)
		80	{
		81
		82	DDRA &= ~(1<<PPM_IN); // set Input Capture Pin as input
		83	PORTA \|= (1<<PPM_IN); // enable pullup
		84
		85	DDRB \|= (1<<PPM_OUT_PIN); // configure PPM_OUT pin as output
		86	SET_PPM_OUT_LOW; // set low
		87
		88	DDRA &= ~(1 << CHANNEL_7_ADC); // Channel 7 (pin12) input
		89	PORTA &= ~(1 << CHANNEL_7_ADC); // disable pullup
		90
		91	DDRA &= ~(1 << CHANNEL_8_ADC); // Channel 8 (pin11) input
		92	PORTA &= ~(1 << CHANNEL_8_ADC); // disable pullup
		93
		94	DDRA &= ~(1 << CHANNEL_9_ADC); // Channel 8 (pin11) input
		95	PORTA &= ~(1 << CHANNEL_9_ADC); // disable pullup
		96
		97	}
		98	/-init_pin-------------------------------------------------------------------/
		99
		100
		101	/*------------------------------------------------------------------------------
		102
		103	function : init_adc(void)
		104	purpose : Initialise ADC registers
		105
		106	*----------------------------------------------------------------------------/
		107	void init_adc(void)
		108	{
		109
		110	cli(); // disable interrupts
		111
		112	DIDR0 \|= ((1<<ADC2D)\|(1<<ADC1D)); // digital input disable for pin 11 and 12
		113	ADMUX = 0x00; // VCC as reference voltage, select channel 0
		114	ADCSRA = (1 << ADPS2) \| (1 << ADPS1)\|\| (0 << ADPS0); // 8.0 [Mhz] / 128 = 62,5 [kHz]
		115	ADCSRB = 0x00; // free running mode
		116
		117	ADC_ENABLE;
		118
		119	sei(); // enable interrupts
		120	}
		121	/-init_adc-------------------------------------------------------------------/
		122
		123
		124	/*------------------------------------------------------------------------------
		125
		126	function : init_timer1(void)
		127	purpose : Initialise timer0
		128	Note(s) : Frequency : 8.0 [Mhz]
		129	8 / 8.0 Mhz : 1.00 [us]
		130
		131	*----------------------------------------------------------------------------/
		132	void init_timer1(void)
		133	{
		134	cli(); // disable interrupts
		135
		136	TCCR1A = ((0<<WGM11)\|(0<<WGM10)); // CTC mode
		137	TCCR1B = ((0<<WGM13)\|(1<<WGM12)\|(0<<CS12)\|(1<<CS11)\|(0<<CS10)); // CTC mode for COMPA, prescaler 8 / 8MHz => [1.0us]
		138
		139	CLEAR_INPUT_CAPTURE_INTERRUPT_FLAG; // reset ICF flag
		140
		141	SET_COUNTER_TO_ZERO;
		142	SET_COMPARE_COUNTER_TO_ZERO;
		143	ENABLE_INPUT_CAPTURE;
		144	DISABLE_OUTPUT_COMPARE;
		145	RISING_EDGE_TRIGGER;
		146
		147	sei(); // enable interrupts
		148	}
		149	/-init_timer1----------------------------------------------------------------/
		150
		151
		152	/*------------------------------------------------------------------------------
		153
		154	function : timer1_capture_interrupt(void)
		155	purpose : Synchronise PPM frame and copy input events to PPM_OUT,
		156	start mixing Ch7, 8 and 9 data when detect start pulse of Ch7
		157
		158	*----------------------------------------------------------------------------/
		159	//#pragma vector=TIM1_CAPT_vect
		160	//static __nested __interrupt void timer1_capture_interrupt (void)
		161	ISR(TIMER1_CAPT_vect)
		162	{
		163	cli(); // disable interrupts
		164	unsigned int data;
		165
		166	switch (ppm_state)
		167	{
		168	case stPPM_SYNC: // detect rising edge pulse
		169	data = ICR1; // get timer value after input capture
		170	SET_COUNTER_TO_ZERO;
		171	FALLING_EDGE_TRIGGER;
		172	if(data >= MIN_SYNC_TIME && data <= MAX_SYNC_TIME) // valid sync trigger
		173	{
		174	SET_PPM_OUT_HIGH;
		175	ppm_state = stPPM_CHANNEL_DATA; // next state: get data
		176	channel_number = 0;
		177	}
		178	else // trigger but not a valid sync time
		179	{
		180	SET_PPM_OUT_LOW;
		181	ppm_state = stPPM_SYNC_WAIT; // next state: wait for next sync event
		182	}
		183	break;
		184
		185	case stPPM_SYNC_WAIT:
		186	SET_PPM_OUT_LOW; // not nessecery, output should already be low
		187	SET_COUNTER_TO_ZERO;
		188	SET_CAPTURE_COUNTER_TO_ZERO;
		189	RISING_EDGE_TRIGGER;
		190	ppm_state = stPPM_SYNC; // next state: try again for new sync
		191	break;
		192
		193	case stPPM_CHANNEL_START: // detect rising edge pulse
		194	SET_COUNTER_TO_ZERO;
		195	SET_PPM_OUT_HIGH;
		196	FALLING_EDGE_TRIGGER;
		197	channel_number++; // prepare for next MX12 channel clock
		198	if(channel_number>5) // all six channels read
		199	{
		200	ppm_state = stPPM_CHANNEL_7_DATA_TRIGGER; // 7th. channel but now self created
		201	channel_number = 0;
		202	}
		203	else
		204	ppm_state = stPPM_CHANNEL_DATA;
		205	break;
		206
		207	case stPPM_CHANNEL_DATA: // detect falling edge pulse
		208	SET_COUNTER_TO_ZERO;
		209	SET_PPM_OUT_LOW;
		210	RISING_EDGE_TRIGGER;
		211	ppm_state = stPPM_CHANNEL_START; // wait for next channel rising edge pulse
		212	break;
		213
		214	case stPPM_CHANNEL_7_DATA_TRIGGER: // detect rising edge pulse
		215	SET_COUNTER_TO_ZERO;
		216	SET_PPM_OUT_LOW;
		217	SET_TIMER_TO_COMPA_CTC;
		218	DISABLE_INPUT_CAPTURE;
		219	ENABLE_OUTPUT_COMPARE;
		220	OCR1A = START_PULSE_LOW; // startpulse length 0.3ms
		221	TRIGGER_INPUT_COMPARE_INTERRUPT;
		222	ppm_state = stPPM_CHANNEL_7_DATA;
		223	break;
		224
		225	default:
		226	SET_PPM_OUT_LOW; // not nessecery, output should already be low
		227	SET_COUNTER_TO_ZERO;
		228	SET_CAPTURE_COUNTER_TO_ZERO;
		229	RISING_EDGE_TRIGGER;
		230	ppm_state = stPPM_SYNC; // next state: try again for new sync
		231	break;
		232
		233	}
		234	sei();
		235	}
		236	/-timer1_capture_interrupt---------------------------------------------------/
		237
		238
		239	/*------------------------------------------------------------------------------
		240
		241	function : timer1_compare_interrupt(void)
		242	purpose : Mixing channel 7, 8 and 9 data into ppm out,
		243	start input capture for frame synchronisation
		244
		245	*----------------------------------------------------------------------------/
		246	//#pragma vector=TIM1_COMPA_vect
		247	//__interrupt void timer1_compare_interrupt (void)
		248	ISR(TIM1_COMPA_vect)
		249	{
		250	cli();
		251	switch (ppm_state)
		252	{
		253	case stPPM_CHANNEL_7_DATA: // create 7th channel data
		254	SET_PPM_OUT_LOW;
		255	SET_COUNTER_TO_ZERO;
		256	OCR1A = channel_7; // COMPA: 0,7ms + channel 7 ADC value
		257	ppm_state = stPPM_CHANNEL_8_START; // next State
		258	break;
		259
		260	case stPPM_CHANNEL_8_START: // create 8th channel start pulse
		261	SET_PPM_OUT_HIGH;
		262	SET_COUNTER_TO_ZERO;
		263	OCR1A = START_PULSE_HIGH; // startpulse length 0.3ms
		264	ppm_state = stPPM_CHANNEL_8_DATA; // next State
		265	break;
		266
		267	case stPPM_CHANNEL_8_DATA: // create 8th channel data
		268	SET_PPM_OUT_LOW;
		269	SET_COUNTER_TO_ZERO;
		270	OCR1A = START_PULSE_LOW + channel_8; // COMPA: 0,7ms + channel 7 ADC value
		271	ppm_state = stPPM_CHANNEL_9_START; // next State
		272	break;
		273
		274	case stPPM_CHANNEL_9_START: // create 8th channel start pulse
		275	SET_PPM_OUT_HIGH;
		276	SET_COUNTER_TO_ZERO;
		277	OCR1A = START_PULSE_HIGH; // startpulse length 0.3ms
		278	ppm_state = stPPM_CHANNEL_9_DATA; // next State
		279	break;
		280
		281	case stPPM_CHANNEL_9_DATA: // create 8th channel data
		282	SET_PPM_OUT_LOW;
		283	SET_COUNTER_TO_ZERO;
		284	OCR1A = START_PULSE_LOW + channel_9; // COMPA: 0,7ms + channel 7 ADC value
		285	ppm_state = stPPM_FINISH_PULSE; // next State
		286	break;
		287
		288	case stPPM_FINISH_PULSE: // create last pulse
		289	SET_PPM_OUT_HIGH;
		290	SET_COUNTER_TO_ZERO;
		291	OCR1A = START_PULSE_HIGH; // startpulse length 0.3ms
		292	ppm_state = stPPM_FINISH_FRAME; // next State
		293	break;
		294
		295	case stPPM_FINISH_FRAME: // create extra low pulse for masking PPM_IN data of channel 7 and 8
		296	SET_PPM_OUT_LOW;
		297	SET_COUNTER_TO_ZERO;
		298	OCR1A = FORCE_LOW_END_FRAME; // keep last end low; 2 channels max - 2 channels min => 2x2ms - 2x1ms + extra length = 2 ms + 1 ms = 3ms => 3000 ticks
		299	ppm_state = stPPM_FRAME_END; // next State
		300	break;
		301
		302	case stPPM_FRAME_END:
		303	default:
		304	RISING_EDGE_TRIGGER;
		305	DISABLE_OUTPUT_COMPARE;
		306	ENABLE_INPUT_CAPTURE;
		307	SET_TIMER_TO_COMPA_CTC;
		308	SET_COUNTER_TO_ZERO;
		309	SET_COMPARE_COUNTER_TO_ZERO;
		310	SET_CAPTURE_COUNTER_TO_ZERO;
		311	ppm_state = stPPM_SYNC; // next State
		312	TRIGGER_INPUT_CAPTURE_INTERRUPT;
		313	break;
		314
		315	}
		316	sei();
		317	}
		318	/-timer1_compare_interrupt---------------------------------------------------/
		319
		320
		321	/*------------------------------------------------------------------------------
		322
		323	function : adc_server(void)
		324	purpose : Handle Analog conversion of RC channel 7, 8 and 9
		325
		326	*----------------------------------------------------------------------------/
		327	//#pragma vector=ADC_vect
		328	//__interrupt void adc_server(void)
		329	ISR(ADC_vect)
		330	{
		331	unsigned int AdcResult;
		332
		333	ADC_DISABLE;
		334
		335	AdcResult = ADC;
		336	if(AdcResult > 1000) // limit conversion value
		337	AdcResult = 1000; // 1000 => 1ms
		338
		339	ADMUX &= ~(ADC_CHANNEL_MASK); // clear channel select bits
		340
		341	if(adc_channel == ADC_CHANNEL_7)
		342	{
		343	channel_7 = AdcResult; // set channel 7 value;
		344	adc_channel = ADC_CHANNEL_8; // set next event for channel 8 conversion
		345	}
		346	else if(adc_channel == ADC_CHANNEL_8)
		347	{
		348	channel_8 = AdcResult; // set channel 8 value;
		349	adc_channel = ADC_CHANNEL_9; // set next event for channel 9 conversion
		350	}
		351	else
		352	{
		353	channel_9 = AdcResult; // set channel 9 value;
		354	adc_channel = ADC_CHANNEL_7; // set next event for channel 7 conversion
		355	}
		356
		357	ADMUX \|= adc_channel; // select new conversion channel
		358
		359	ADC_ENABLE;
		360	}
		361	/-adc_server-----------------------------------------------------------------/
		362
		363
		364	/*------------------------------------------------------------------------------
		365
		366	function : check_valid_adc_value(void)
		367	purpose : wait until 3 ADC channels are processed at least once
		368	before init Input Capture/Timer1
		369
		370	*----------------------------------------------------------------------------/
		371	void check_valid_adc_value (void)
		372	{
		373	unsigned char exit = FALSE;
		374
		375	do
		376	{
		377	if(channel_7 < 0xffff && channel_8 < 0xffff && channel_9 < 0xffff) // both channels must be processed
		378	exit = TRUE;
		379
		380	}while (!exit);
		381	}
		382	/-check_valid_adc_value------------------------------------------------------/
		383
		384
		385	/*------------------------------------------------------------------------------
		386
		387	function : main(void)
		388
		389	*----------------------------------------------------------------------------/
		390	int main(void)
		391	{
		392
		393	init_pin();
		394	init_adc();
		395	check_valid_adc_value(); // wait until both ADC channels are processed at least once
		396	init_timer1();
		397
		398	while(1)
		399	{}
		400	}
		401
		402	/-main-----------------------------------------------------------------------/
		403

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