11,10 → 11,15 |
// The channel array is 0-based! |
volatile int16_t PPM_in[MAX_CHANNELS]; |
volatile int16_t PPM_diff[MAX_CHANNELS]; |
volatile uint16_t RC_buffer[MAX_CHANNELS]; |
volatile uint8_t inBfrPnt = 0; |
|
volatile uint8_t RCQuality; |
uint8_t lastRCCommand = COMMAND_NONE; |
uint8_t commandTimer = 0; |
|
#define TIME(s) ((int16_t)(((long)F_CPU/(long)64000)*(float)s + 0.5f)) |
|
/*************************************************************** |
* 16bit timer 1 is used to decode the PPM-Signal |
***************************************************************/ |
41,18 → 46,23 |
PORTD &= ~(1<<PORTD3); |
} |
|
// Timer/Counter1 Control Register A, B, C |
|
// Normal Mode (bits: WGM13=0, WGM12=0, WGM11=0, WGM10=0) |
// Compare output pin A & B is disabled (bits: COM1A1=0, COM1A0=0, COM1B1=0, COM1B0=0) |
// Set clock source to SYSCLK/64 (bit: CS12=0, CS11=1, CS10=1) |
// Enable input capture noise cancler (bit: ICNC1=1) |
// Trigger on positive edge of the input capture pin (bit: ICES1=1), |
// Therefore the counter incremets at a clock of 20 MHz/64 = 312.5 kHz or 3.2�s |
// The longest period is 0xFFFF / 312.5 kHz = 0.209712 s. |
TCCR1A &= ~((1 << COM1A1) | (1 << COM1A0) | (1 << COM1B1) | (1 << COM1B0) | (1 << WGM11) | (1 << WGM10)); |
TCCR1B &= ~((1 << WGM13) | (1 << WGM12) | (1 << CS12)); |
TCCR1B |= (1 << CS11) | (1 << CS10) | (1 << ICES1) | (1 << ICNC1); |
TCCR1A &= ~((1<<COM1A1)| (1<<COM1A0) | (1<<COM1B1) | (1<<COM1B0) | (1<<WGM11) | (1<<WGM10)); |
TCCR1B &= ~((1<<WGM13) | (1<<WGM12) | (1<<CS12)); |
TCCR1B |= (1<<CS11) | (1<<CS10) | (1<<ICNC1); |
TCCR1C &= ~((1<<FOC1A) | (1<<FOC1B)); |
|
if (channelMap.RCPolarity) { |
TCCR1B |= (1<<ICES1); |
} else { |
TCCR1B &= ~(1<<ICES1); |
} |
|
TCCR1C &= ~((1 << FOC1A) | (1 << FOC1B)); |
|
// Timer/Counter1 Interrupt Mask Register |
67,6 → 77,22 |
SREG = sreg; |
} |
|
/* |
* This new and much faster interrupt handler should reduce servo jolts. |
*/ |
ISR(TIMER1_CAPT_vect) { |
static uint16_t oldICR1 = 0; |
uint16_t signal = (uint16_t)ICR1 - oldICR1; |
oldICR1 = ICR1; |
//sync gap? (3.5 ms < signal < 25.6 ms) |
if (signal > TIME(3.5)) { |
inBfrPnt = 0; |
} else if (inBfrPnt<MAX_CHANNELS) { |
RC_buffer[inBfrPnt++] = signal; |
if (RCQuality <= 200-4) RCQuality+=4; else RCQuality = 200; |
} |
} |
|
/********************************************************************/ |
/* Every time a positive edge is detected at PD6 */ |
/********************************************************************/ |
88,64 → 114,18 |
The remaining time of (22.5 - 8 ms) ms = 14.5 ms to (22.5 - 16 ms) ms = 6.5 ms is |
the syncronization gap. |
*/ |
ISR(TIMER1_CAPT_vect) { // typical rate of 1 ms to 2 ms |
int16_t signal = 0, tmp; |
static int16_t index; |
static uint16_t oldICR1 = 0; |
|
// 16bit Input Capture Register ICR1 contains the timer value TCNT1 |
// at the time the edge was detected |
|
// calculate the time delay to the previous event time which is stored in oldICR1 |
// calculatiing the difference of the two uint16_t and converting the result to an int16_t |
// implicit handles a timer overflow 65535 -> 0 the right way. |
signal = (uint16_t) ICR1 - oldICR1; |
oldICR1 = ICR1; |
|
//sync gap? (3.52 ms < signal < 25.6 ms) |
if ((signal > 1100) && (signal < 8000)) { |
index = 0; |
} else { // within the PPM frame |
if (index < MAX_CHANNELS) { // PPM24 supports 12 channels |
// check for valid signal length (0.8 ms < signal < 2.1984 ms) |
// signal range is from 1.0ms/3.2us = 312 to 2.0ms/3.2us = 625 |
if ((signal > 250) && (signal < 687)) { |
// shift signal to zero symmetric range -154 to 159 |
signal -= 475; // offset of 1.4912 ms ??? (469 * 3.2us = 1.5008 ms) |
// check for stable signal |
if (abs(signal - PPM_in[index]) < 6) { |
if (RCQuality < 200) |
RCQuality += 10; |
else |
RCQuality = 200; |
} |
// If signal is the same as before +/- 1, just keep it there. Naah lets get rid of this slimy sticy stuff. |
// if (signal >= PPM_in[index] - 1 && signal <= PPM_in[index] + 1) { |
// In addition, if the signal is very close to 0, just set it to 0. |
if (signal >= -1 && signal <= 1) { |
tmp = 0; |
//} else { |
// tmp = PPM_in[index]; |
// } |
} else |
tmp = signal; |
// calculate signal difference on good signal level |
if (RCQuality >= 195) |
PPM_diff[index] = signal - PPM_in[index]; //((tmp - PPM_in[index]) / 3) * 3; // cut off lower 3 bit for nois reduction |
else |
PPM_diff[index] = 0; |
PPM_in[index] = tmp; // update channel value |
void RC_process(void) { |
if (RCQuality) RCQuality--; |
for (uint8_t channel=0; channel<MAX_CHANNELS; channel++) { |
uint16_t signal = RC_buffer[channel]; |
if (signal != 0) { |
RC_buffer[channel] = 0; // reset to flag value already used. |
if ((signal >= TIME(0.8)) && (signal < TIME(2.2))) { |
signal -= TIME(1.5); |
PPM_diff[channel] = signal - PPM_in[channel]; |
PPM_in[channel] = signal; |
} |
index++; // next channel |
// demux sum signal for channels 5 to 7 to J3, J4, J5 |
// TODO: General configurability of this R/C channel forwarding. Or remove it completely - the |
// channels are usually available at the receiver anyway. |
// if(index == 5) J3HIGH; else J3LOW; |
// if(index == 6) J4HIGH; else J4LOW; |
// if(CPUType != ATMEGA644P) // not used as TXD1 |
// { |
// if(index == 7) J5HIGH; else J5LOW; |
// } |
} |
} |
} |
182,6 → 162,7 |
*/ |
void RC_periodicTaskAndPRTY(int16_t* PRTY) { |
int16_t tmp1, tmp2; |
RC_process(); |
if (RCQuality) { |
RCQuality--; |
PRTY[CONTROL_PITCH] = RCChannel(CH_PITCH) * staticParams.stickP + RCDiff(CH_PITCH) * staticParams.stickD; |