1,119 → 1,202 |
#include <avr/io.h> |
#include <avr/interrupt.h> |
#include "timer2.h" |
#include "eeprom.h" |
#include "uart0.h" |
#include "rc.h" |
#include "attitude.h" |
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#define HEF4017_RESET_HIGH PORTC |= (1<<PORTC6) |
#define HEF4017_RESET_LOW PORTC &= ~(1<<PORTC6) |
#define COARSERESOLUTION 1 |
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#define HEF4017R_ON PORTC |= (1<<PORTC6) |
#define HEF4017R_OFF PORTC &= ~(1<<PORTC6) |
#ifdef COARSERESOLUTION |
#define NEUTRAL_PULSELENGTH 938 |
#define STABILIZATION_LOG_DIVIDER 6 |
#define SERVOLIMIT 500 |
#define SCALE_FACTOR 4 |
#define CS2 ((1<<CS21)|(1<<CS20)) |
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OutputData_t outputs[MAX_OUTPUTS]; |
#else |
#define NEUTRAL_PULSELENGTH 3750 |
#define STABILIZATION_LOG_DIVIDER 4 |
#define SERVOLIMIT 2000 |
#define SCALE_FACTOR 16 |
#define CS2 (1<<CS21) |
#endif |
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#define MAX_SERVOS 8 |
#define FRAMELEN ((NEUTRAL_PULSELENGTH + SERVOLIMIT) * staticParams.servoCount + 128) |
#define MIN_PULSELENGTH (NEUTRAL_PULSELENGTH - SERVOLIMIT) |
#define MAX_PULSELENGTH (NEUTRAL_PULSELENGTH + SERVOLIMIT) |
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//volatile uint8_t servoActive = 0; |
volatile uint8_t recalculateServoTimes = 0; |
volatile uint16_t servoValues[MAX_SERVOS]; |
volatile uint16_t previousManualValues[2]; |
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#define HEF4017R_ON PORTC |= (1<<PORTC6) |
#define HEF4017R_OFF PORTC &= ~(1<<PORTC6) |
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/***************************************************** |
* Initialize Timer 2 |
* Initialize Timer 2 |
*****************************************************/ |
void timer2_init(void) { |
uint8_t sreg = SREG; |
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// disable all interrupts before reconfiguration |
cli(); |
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// set PD7 as output of the PWM for pitch servo |
DDRD |= (1 << DDD7); |
PORTD &= ~(1 << PORTD7); // set PD7 to low |
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DDRC |= (1 << DDC6); // set PC6 as output (Reset for HEF4017) |
//PORTC &= ~(1<<PORTC6); // set PC6 to low |
HEF4017_RESET_HIGH; // enable reset |
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// Timer/Counter 2 Control Register A |
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// Timer Mode is CTC (Bits: WGM22 = 0, WGM21 = 1, WGM20 = 0) |
// PD7: Normal port operation, OC2A disconnected, (Bits: COM2A1 = 0, COM2A0 = 0) |
// PD6: Normal port operation, OC2B disconnected, (Bits: COM2B1 = 0, COM2B0 = 0) |
TCCR2A &= ~((1 << COM2A1) | (1 << COM2A0) | (1 << COM2B1) | (1 << COM2B0)); |
TCCR2A |= (1 << WGM21); |
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// Timer/Counter 2 Control Register B |
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// Set clock divider for timer 2 to SYSKLOCK/32 = 20MHz / 32 = 625 kHz |
// The timer increments from 0x00 to 0xFF with an update rate of 625 kHz or 1.6 us |
// hence the timer overflow interrupt frequency is 625 kHz / 256 = 2.44 kHz or 0.4096 ms |
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// divider 32 (Bits: CS022 = 0, CS21 = 1, CS20 = 1) |
TCCR2B &= ~((1 << FOC2A) | (1 << FOC2B) | (1 << CS22)); |
TCCR2B |= (1 << CS21) | (1 << CS20); |
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// Initialize the Timer/Counter 2 Register |
TCNT2 = 0; |
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// Initialize the Output Compare Register A used for signal generation on port PD7. |
OCR2A = 255; |
TCCR2A |= (1 << COM2A1); // set or clear at compare match depends on value of COM2A0 |
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// Timer/Counter 2 Interrupt Mask Register |
// Enable timer output compare match A Interrupt only |
TIMSK2 &= ~((1 << OCIE2B) | (1 << TOIE2)); |
TIMSK2 |= (1 << OCIE2A); |
uint8_t sreg = SREG; |
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SREG = sreg; |
// disable all interrupts before reconfiguration |
cli(); |
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// set PD7 as output of the PWM for pitch servo |
DDRD |= (1 << DDD7); |
PORTD &= ~(1 << PORTD7); // set PD7 to low |
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DDRC |= (1 << DDC6); // set PC6 as output (Reset for HEF4017) |
HEF4017R_ON; // enable reset |
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// Timer/Counter 2 Control Register A |
// Timer Mode is CTC (Bits: WGM22 = 0, WGM21 = 1, WGM20 = 0) |
// PD7: Output OCR2 match, (Bits: COM2A1 = 1, COM2A0 = 0) |
// PD6: Normal port operation, OC2B disconnected, (Bits: COM2B1 = 0, COM2B0 = 0) |
TCCR2A &= ~((1 << COM2A0) | (1 << COM2B1) | (1 << COM2B0) | (1 << WGM20) | (1 << WGM22)); |
TCCR2A |= (1 << COM2A1) | (1 << WGM21); |
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// Timer/Counter 2 Control Register B |
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// Set clock divider for timer 2 to 20MHz / 8 = 2.5 MHz |
// The timer increments from 0x00 to 0xFF with an update rate of 2.5 kHz or 0.4 us |
// hence the timer overflow interrupt frequency is 625 kHz / 256 = 9.765 kHz or 0.1024ms |
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TCCR2B &= ~((1 << FOC2A) | (1 << FOC2B) | (1 << CS20) | (1 << CS21) | (1 << CS22)); |
TCCR2B |= CS2; |
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// Initialize the Timer/Counter 2 Register |
TCNT2 = 0; |
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// Initialize the Output Compare Register A used for signal generation on port PD7. |
OCR2A = 255; |
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// Timer/Counter 2 Interrupt Mask Register |
// Enable timer output compare match A Interrupt only |
TIMSK2 &= ~((1 << OCIE2B) | (1 << TOIE2)); |
TIMSK2 |= (1 << OCIE2A); |
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for (uint8_t axis=0; axis<2; axis++) |
previousManualValues[axis] = dynamicParams.servoManualControl[axis] * SCALE_FACTOR; |
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SREG = sreg; |
} |
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/* |
void servo_On(void) { |
servoActive = 1; |
} |
void servo_Off(void) { |
servoActive = 0; |
HEF4017R_ON; // enable reset |
} |
*/ |
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/***************************************************** |
* Control Servo Position |
* Control Servo Position |
*****************************************************/ |
const uint8_t SERVO_REMAPPING[MAX_OUTPUTS] = {0,0,1,2,3,4,5,6}; |
#define NEUTRAL_PULSELENGTH 937 |
#define SERVOLIMIT 500 |
#define FRAMELEN ((NEUTRAL_PULSELENGTH + SERVOLIMIT) * staticParams.ServoRefresh + 128) |
#define MIN_PULSELENGTH (NEUTRAL_PULSELENGTH - SERVOLIMIT) |
#define MAX_PULSELENGTH (NEUTRAL_PULSELENGTH + SERVOLIMIT) |
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/*typedef struct { |
uint8_t manualControl; |
uint8_t compensationFactor; |
uint8_t minValue; |
uint8_t maxValue; |
uint8_t flags; |
} servo_t;*/ |
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int16_t calculateStabilizedServoAxis(uint8_t axis) { |
int32_t value = attitude[axis] >> STABILIZATION_LOG_DIVIDER; // between -500000 to 500000 extreme limits. Just about |
// With full blast on stabilization gain (255) we want to convert a delta of, say, 125000 to 2000. |
// That is a divisor of about 1<<14. Same conclusion as H&I. |
value *= staticParams.servoConfigurations[axis].stabilizationFactor; |
value = value >> 8; |
if (staticParams.servoConfigurations[axis].flags & SERVO_STABILIZATION_REVERSE) |
return -value; |
return value; |
} |
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// With constant-speed limitation. |
uint16_t calculateManualServoAxis(uint8_t axis, uint16_t manualValue) { |
int16_t diff = manualValue - previousManualValues[axis]; |
uint8_t maxSpeed = staticParams.servoManualMaxSpeed; |
if (diff > maxSpeed) diff = maxSpeed; |
else if (diff < -maxSpeed) diff = -maxSpeed; |
manualValue = previousManualValues[axis] + diff; |
previousManualValues[axis] = manualValue; |
return manualValue; |
} |
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// add stabilization and manual, apply soft position limits. |
// All in a [0..255*SCALE_FACTOR] space (despite signed types used internally) |
int16_t featuredServoValue(uint8_t axis) { |
int16_t value = calculateManualServoAxis(axis, dynamicParams.servoManualControl[axis] * SCALE_FACTOR); |
value += calculateStabilizedServoAxis(axis); |
int16_t limit = staticParams.servoConfigurations[axis].minValue * SCALE_FACTOR; |
if (value < limit) value = limit; |
limit = staticParams.servoConfigurations[axis].maxValue * SCALE_FACTOR; |
if (value > limit) value = limit; |
return value; |
} |
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uint16_t servoValue(uint8_t axis) { |
int16_t value; |
if (axis<2) value = featuredServoValue(axis); |
else value = 128 * SCALE_FACTOR; // dummy. Replace by something useful for servos 3..8. |
// Shift out of the [0..255*SCALE_FACTOR] space |
value -= (128 * SCALE_FACTOR); |
if (value < -SERVOLIMIT) value = -SERVOLIMIT; |
else if (value > SERVOLIMIT) value = SERVOLIMIT; |
// Shift into the [NEUTRAL_PULSELENGTH-SERVOLIMIT..NEUTRAL_PULSELENGTH+SERVOLIMIT] space. |
return value + NEUTRAL_PULSELENGTH; |
} |
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void calculateServoValues(void) { |
if (!recalculateServoTimes) return; |
for (uint8_t axis=0; axis<MAX_SERVOS; axis++) { |
servoValues[axis] = servoValue(axis); |
} |
recalculateServoTimes = 0; |
} |
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ISR(TIMER2_COMPA_vect) { |
static uint16_t remainingPulseTime = 0; |
static uint16_t remainingPulseTime; |
static uint8_t servoIndex = 0; |
static uint16_t sumOfPulseTimes = 0; |
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if (!remainingPulseTime) { |
// Pulse is over, and the next pulse has already just started. Calculate length of next pulse. |
if (servoIndex < staticParams.ServoRefresh) { |
if (servoIndex < staticParams.servoCount) { |
// There are more signals to output. |
remainingPulseTime = NEUTRAL_PULSELENGTH + outputs[SERVO_REMAPPING[servoIndex]].SetPoint; |
if (remainingPulseTime < MIN_PULSELENGTH) remainingPulseTime = MIN_PULSELENGTH; |
else if (remainingPulseTime > MAX_PULSELENGTH) remainingPulseTime = MAX_PULSELENGTH; |
sumOfPulseTimes += remainingPulseTime; |
sumOfPulseTimes += (remainingPulseTime = servoValues[servoIndex]); |
servoIndex++; |
} else { |
// There are no more signals. Reset the counter and make this pulse cover the missing frame time. |
remainingPulseTime = FRAMELEN - sumOfPulseTimes; |
sumOfPulseTimes = servoIndex = 0; |
HEF4017_RESET_HIGH; |
recalculateServoTimes = 1; |
HEF4017R_ON; |
} |
} |
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// Schedule the next OCR2A event. The counter is already reset at this time. |
uint8_t delta; |
if (remainingPulseTime > 255+128) { |
delta = 255; |
// Set output to reset to zero at next OCR match. It does not really matter when the output is set low again, |
if (remainingPulseTime > 256+128) { |
// Set output to reset to zero at next OCR match. It does not really matter when the output is set low again, |
// as long as it happens once per pulse. This will, because all pulses are > 255+128 long. |
OCR2A = 255; |
TCCR2A &= ~(1<<COM2A0); |
} else if (remainingPulseTime > 255) { |
// Remaining pulse lengths in the range [256..256+something small] might cause trouble if handled the standard |
// way, which is in chunks of 255. The remainder would be very small, possibly causing an interrupt on interrupt |
remainingPulseTime-=256; |
} else if (remainingPulseTime > 256) { |
// Remaining pulse lengths in the range [256..256+128] might cause trouble if handled the standard |
// way, which is in chunks of 256. The remainder would be very small, possibly causing an interrupt on interrupt |
// condition. Instead we now make a chunk of 128. The remaining chunk will then be in [128..255] which is OK. |
delta = 128; |
remainingPulseTime-=128; |
OCR2A=127; |
} else { |
delta = remainingPulseTime; |
// Set output to high at next OCR match. This is when the 4017 counter will advance by one. Also set reset low |
TCCR2A |= (1<<COM2A0); |
HEF4017_RESET_LOW; // implement servo-disable here, by only removing the reset signal if ServoEnabled!=0. |
OCR2A = remainingPulseTime-1; |
remainingPulseTime=0; |
HEF4017R_OFF; // implement servo-disable here, by only removing the reset signal if ServoEnabled!=0. |
} |
OCR2A = delta; |
remainingPulseTime -= delta; |
} |