/* * TinyRC2 I/O using Sum PPM Signal * * Attiny 26 * * set fuses for 4MHz internal RC Osc * avrdude -c USBasp -p t26 -U lfuse:w:0xE3:m -U hfuse:w:0x17:m * * program flash with * avrdude -c USBasp -p t26 -U flash:w:TinyRC2.hex * * Author: Heinz & Florian Bruederlin * 16.02.09 First implemented * 01.04.09 Warn implemented * 10.04.09 Wink reversed * * Channels of "webra nano S6" * 1 = Lift * 2 = Motor * 3 = Tip * 4 = Steering * 5 = Light / Blink / Both * 6 = Horn / Warnwink / Both */ #ifndef F_CPU #define F_CPU 4000000 /* Clock in HZ */ #endif #include #include #include /* PORTA defines */ /* all anodes of the LEDs at PORTA are connected to VCC */ /* they are switched on with logic 0 value (inverted) */ #define RC_NOK_OUT PA0 #define BLINK0_OUT PA1 #define BLINK1_OUT PA2 #define BLINK2_OUT PA3 #define BLINK3_OUT PA4 #define BLINK4_OUT PA5 #define BLINK5_OUT PA6 #define BLINK6_OUT PA7 #define BLINKX_OUT (_BV(BLINK0_OUT) | _BV(BLINK1_OUT) | \ _BV(BLINK2_OUT) | _BV(BLINK3_OUT) | \ _BV(BLINK4_OUT) | _BV(BLINK5_OUT) | \ _BV(BLINK6_OUT)) /* PORTB defines */ /* all outputs at PORTB are connected to driver transistors */ /* they are switched on with logic 1 value */ #define LIGHT_OUT PB0 #define LOUDSP_OUT PB3 #define WINKL_OUT PB4 #define WINKR_OUT PB5 #define REC_IN PB6 /* RC range defines */ #define RC_MIN_VALUE 64 #define RC_MID_VALUE 98 #define RC_MAX_VALUE 128 #define RC_TOL_VALUE 14 // tolerance for bad value #define RC_MIN_GAP 160 // GAP must be at least 3msec /* RC states */ #define RC_WAIT_FOR_START 0 #define RC_TIME_CHANNEL 1 #define RC_GOT_LONG_GAP 2 static volatile unsigned char rc_state = RC_WAIT_FOR_START; /* valid rc values received */ static volatile unsigned char rc_valid = 0; /* RC channels */ #define RC_CHANNEL_CNT 6 static volatile unsigned char rc_channel = 0; static volatile unsigned char rc_value[RC_CHANNEL_CNT]; /* RC switch levels */ #define RC_MID_TOL 10 // tolerance around RC_MID_VALUE, which is ignored #define RC_IS_WINKL (rc_value[3] > RC_MID_VALUE+RC_MID_TOL) #define RC_IS_WINKR (rc_value[3] < RC_MID_VALUE-RC_MID_TOL) #define RC_IS_BEEP (rc_value[1] < RC_MID_VALUE-RC_MID_TOL) #define RC_SWITCH(v) (((v)-RC_MIN_VALUE)/((RC_MAX_VALUE-RC_MIN_VALUE)/4)) // divide channel into 4 ranges #define RC_IS_LIGHT (RC_SWITCH(rc_value[4])==1 || RC_SWITCH(rc_value[4])>=3) #define RC_IS_BLINK (RC_SWITCH(rc_value[4])==2 || RC_SWITCH(rc_value[4])>=3) #define RC_IS_HORN (RC_SWITCH(rc_value[5])==1 || RC_SWITCH(rc_value[5])>=3) #define RC_IS_WARN (RC_SWITCH(rc_value[5])==2 || RC_SWITCH(rc_value[5])>=3) /* timing stuff */ #define TONE_HIGH_CMP 125 // 4MHz/64/125 = 500Hz #define TONE_LOW_CMP 250 // 4Mhz/64/250 = 250Hz #define TONE_HIGH_DIV 50-1 // 500Hz/50 = 10Hz #define TONE_LOW_DIV 25-1 // 250Hz/25 = 10Hz static volatile unsigned char tone_div = 0; // current divider static volatile unsigned char tone_cnt = 0; // current divider value #define WINK_FREQ 3-1 // 10/3 = 3.3Hz static volatile unsigned char wink_cnt = 0; // current wink value #define BLINK_FREQ 1-1 // 10/1 = 10Hz static volatile unsigned char blink_cnt = 0; // current blink value static volatile unsigned char blink_state = 0; // current blink value static volatile unsigned char beep_cnt = 0; // current blink value /* * io_init - * init io ports */ void io_init(void) { /* switch off LEDs */ PORTA = _BV(BLINK0_OUT) | _BV(BLINK1_OUT) | _BV(BLINK2_OUT) | _BV(BLINK3_OUT) | _BV(BLINK4_OUT) | _BV(BLINK5_OUT) | _BV(BLINK6_OUT) | _BV(RC_NOK_OUT); /* Set PORT A outputs */ DDRA = _BV(BLINK0_OUT) | _BV(BLINK1_OUT) | _BV(BLINK2_OUT) | _BV(BLINK3_OUT) | _BV(BLINK4_OUT) | _BV(BLINK5_OUT) | _BV(BLINK6_OUT) | _BV(RC_NOK_OUT); /* clear outputs and set pullups */ PORTB = _BV(REC_IN); // enable pullup for input // and switch off LEDs /* Set PORT B to outputs */ DDRB = _BV(LIGHT_OUT) | _BV(LOUDSP_OUT) | _BV(WINKL_OUT) | _BV(WINKR_OUT); } /* * timer_init - * init timer stuff * * prescaler for timer0 is set to 64, which will result in an * interrupt every 16usec. * 64 ticks are equal to approx. 1msec * 128 ticks are equal to approx. 2msec * 255 ticks are equal to approx. 4msec * The absolute maximum range with the FC-16 is 61..134 * * prescaler for timer1 is set to 64. * in a frequency of 4MHz/64/OCR1C or * OCR1C | Freq * ------|------- * 250 | 250Hz * 125 | 500Hz * 104 | 601Hz * 64 | 976Hz * 62 | 1042Hz * 31 | 2016Hz */ void timer_init(void) { TCCR0 |= _BV(CS01) | _BV(CS00); // set timer0 prescaler to 64 TCNT0 = 0; // clear timer0 TIFR |= _BV(TOV0); // clear pending overflow TCCR1B |= _BV(CS12) | _BV(CS11) | _BV(CS10) | // set timer1 prescaler to 64 _BV(CTC1); // clear timer1 on cmp match } /* * tone_set - * set high/low frequency for sound (and timing). * we avoid glitches, by checking if we have already the right settings */ void tone_set(unsigned char high) { if (high) { if (tone_div != TONE_HIGH_DIV) { OCR1C = TONE_HIGH_CMP; tone_div = TONE_HIGH_DIV; } } else { if (tone_div != TONE_LOW_DIV) { OCR1C = TONE_LOW_CMP; tone_div = TONE_LOW_DIV; } } } /* * sound_set - * enable/disable sound output * we check wether the TCCR1A has already the right settings * to avoid gliches, when set/reset multiple times. */ void sound_set(unsigned char on) { if (on) { if (!(TCCR1A & _BV(COM1B0))) { TCCR1A |= _BV(COM1B0); } } else { if (TCCR1A & _BV(COM1B0)) { TCCR1A &= ~_BV(COM1B0); PORTB &= ~_BV(LOUDSP_OUT); // switch off loudspeaker output } } } /* * intr_init - * init interrupts * timer1 overflow is used to recognize the end of a PPM frame after 3+n*4msec * the external interrupt INT0 will be used to recognize the * falling edge of the PPM channels: * _ _ _ _ * | | | | | | | | * ______| |___| |____| |___________| |_ * <-----><-----><------------><--.. * CH1 CH2 Gap CH1 * 1..2ms 1..2ms ~4..12ms */ void intr_init(void) { TIMSK |= _BV(TOIE0) | // enable timer0 overflow interrupt _BV(OCIE1B); // enable timer1 output cmp interrupt //falling edge generates an interrupt MCUCR |= _BV(ISC01); // enable external interrupt on PB6 (REC_IN) GIMSK |= _BV(INT0); // enable interupts sei(); } /* * TIMER0_OVF0_vect - * timer 0 overflow interrupt handler * if the timer overflows while measuring a channel we wait for a new start. * if we are waiting for start, the gap is longer than 4msec. */ ISR(TIMER0_OVF0_vect) { switch (rc_state) { case RC_WAIT_FOR_START: rc_state = RC_GOT_LONG_GAP; break; case RC_GOT_LONG_GAP: /* long gap gets even longer */; break; case RC_TIME_CHANNEL: if (rc_channel < RC_CHANNEL_CNT) { rc_valid = 0; rc_state = RC_WAIT_FOR_START; } else { rc_state = RC_GOT_LONG_GAP; } break; } } /* * INT0_vect - * external interrupt 0 * called on each falling edge of PB6 (REC_IN) * because we have only a 8bit timer, we recognize * the start of a frame, if there was an overflow, or * the start gap is at least RC_MIN_GAP long. * A valid channel value must be between RC_MIN_VALUE and RC_MAX_VALUE. * In all other cases (too short start, or invalid channel value) * we go to the RC_WAIT_FOR_START state. * A valid frame is signaled by setting rc_value to 1, if we have * received RC_CHANNEL_CNT valid values and got a long enough start gap. */ ISR(INT0_vect) { unsigned char value = TCNT0; // store width of this channel TCNT0 = 0; // start measurement of next channel TIFR |= _BV(TOV0); // clear Overflow which occured while we are in // in this interrupt with higher prio. switch (rc_state) { case RC_WAIT_FOR_START: case RC_GOT_LONG_GAP: if (value > RC_MIN_GAP || rc_state==RC_GOT_LONG_GAP) { if (rc_channel>=RC_CHANNEL_CNT) rc_valid = 1; rc_channel = 0; rc_state = RC_TIME_CHANNEL; } break; case RC_TIME_CHANNEL: if (value < RC_MIN_VALUE-RC_TOL_VALUE || value > RC_MAX_VALUE+RC_TOL_VALUE) { rc_valid = 0; rc_state = RC_WAIT_FOR_START; } else if (rc_channel < RC_CHANNEL_CNT) { rc_value[rc_channel] = value; } rc_channel++; break; } } /* * TIMER1_CMPB_vect - * timer1 controls the loudspeaker * with one of two OCR settings: TONE_HIGH_CMP and TONE_LOW_CMP * is runs with 4MHz/64/TONE_HIGH_CMP or 4Mhz/64/TONE_LOW_CMP. * This interrupt divides this by TONE_HIGH_DIV or * TONE_LOW_DIV depending on variable tone_high, * to get a fixed 10Hz clock. * * This 10Hz is used for the timing of Blinking and other stuff. */ ISR(TIMER1_CMPB_vect) { if (tone_cnt) { tone_cnt--; return; } tone_cnt = tone_div; // the following code will run with 10Hz if (!rc_valid) return; // Winker Code if (wink_cnt) { wink_cnt--; } else { wink_cnt = WINK_FREQ; if (RC_IS_WINKR || RC_IS_WARN) { PORTB ^= _BV(WINKR_OUT); } else { PORTB &= ~_BV(WINKR_OUT); } if (RC_IS_WINKL || RC_IS_WARN) { PORTB ^= _BV(WINKL_OUT); } else { PORTB &= ~_BV(WINKL_OUT); } } // Blinker code if (blink_cnt) { blink_cnt--; } else { blink_cnt = BLINK_FREQ; if (RC_IS_BLINK) { unsigned char b; blink_state++; if (blink_state>6) blink_state=0; PORTA |= BLINKX_OUT; // all off switch (blink_state) { case 0: b = (unsigned char)(~_BV(BLINK0_OUT)); break; case 1: b = (unsigned char)(~_BV(BLINK1_OUT)); break; case 2: b = (unsigned char)(~_BV(BLINK2_OUT)); break; case 3: b = (unsigned char)(~_BV(BLINK3_OUT)); break; case 4: b = (unsigned char)(~_BV(BLINK4_OUT)); break; case 5: b = (unsigned char)(~_BV(BLINK5_OUT)); break; default: b = (unsigned char)(~_BV(BLINK6_OUT)); break; } PORTA = (PORTA | BLINKX_OUT) & b; } else { PORTA |= BLINKX_OUT; // all off } } // beeper code if (RC_IS_BEEP && !RC_IS_HORN) { switch (beep_cnt) { case 0: sound_set(1); beep_cnt++; break; case 1: case 2: beep_cnt++; break; case 3: sound_set(0); beep_cnt++; break; case 4: beep_cnt=0; break; } } else { sound_set(0); } } /* * main - * init everthing and go to endlees loop */ int main(void) { io_init(); timer_init(); intr_init(); for(;;) { if (rc_valid) { PORTA |= _BV(RC_NOK_OUT); // rc not ok LED off if (RC_IS_HORN) { tone_set(0); // low frequence sound sound_set(1); // enable loudspeaker } else { tone_set(1); // high frequence sound for beep and timing if (!RC_IS_BEEP) { sound_set(0); // disable loudspeaker if not backward beeping } } if (RC_IS_LIGHT) { PORTB |= _BV(LIGHT_OUT); // light LEDs on } else { PORTB &= ~_BV(LIGHT_OUT); // light LEDs off } } else { PORTA &= ~_BV(RC_NOK_OUT); // rc not ok LED on PORTA |= BLINKX_OUT; // blink LEDs off PORTB &= ~_BV(LIGHT_OUT) & // light LED off ~_BV(WINKR_OUT) & // right winker off ~_BV(WINKL_OUT); // left winker off sound_set(0); // disable loudspeaker } } }