diff options
| author | Christian Pointner <equinox@spreadspace.org> | 2021-09-12 23:38:19 +0200 |
|---|---|---|
| committer | Christian Pointner <equinox@spreadspace.org> | 2021-09-12 23:38:19 +0200 |
| commit | fa0c389e56f76a631a4616bf36b85ff7ee875c04 (patch) | |
| tree | d521e746b3d84667225b60161482d8ec99198096 | |
| parent | basic PWM works now (diff) | |
add fan tacho
| -rw-r--r-- | table-fan/Makefile | 1 | ||||
| -rw-r--r-- | table-fan/table-fan.c | 36 |
2 files changed, 33 insertions, 4 deletions
diff --git a/table-fan/Makefile b/table-fan/Makefile index c41073f..85f972c 100644 --- a/table-fan/Makefile +++ b/table-fan/Makefile @@ -26,6 +26,7 @@ OBJ := $(NAME).o LIBS := util led lufa-descriptor-usbserial usbio EXTERNAL_LIBS := lufa SPREADAVR_PATH := ../contrib/avr-utils +PRINTF_HAS_FLOAT := 1 RESET_FUNC := $(SPREADAVR_PATH)/tools/reset_lufa_cdc RESET_PARAM := 'r' diff --git a/table-fan/table-fan.c b/table-fan/table-fan.c index 2cf9a32..0a49c91 100644 --- a/table-fan/table-fan.c +++ b/table-fan/table-fan.c @@ -65,6 +65,37 @@ inline void pwm_dec(void) PWM_VAL--; } + +void tacho_init(void) +{ + DDRD &= ~(1<<PD4); + PORTD |= (1<<PD4); + TCCR1B = 0; // make sure timer is stopped + + TCCR1A = 0; + TCNT1 = 0; + TIMSK1 = (1<<ICIE1); + + TCCR1B = (1<<CS12); // start timer +} + +ISR(TIMER1_CAPT_vect) +{ + static uint16_t tacho_last_ts = 0; + uint16_t current = ICR1; + uint16_t diff = 0; + if(current > tacho_last_ts) { + diff = current - tacho_last_ts; + } else { + diff = (UINT16_MAX - tacho_last_ts) + current; + } + tacho_last_ts = current; + + float rpm = 1875000.0 / (float)diff ; + printf("\rtacho: %8.2f rpm", rpm); +} + + void handle_cmd(uint8_t cmd) { switch(cmd) { @@ -89,12 +120,9 @@ int main(void) led_init(); usbio_init(); pwm_init(); + tacho_init(); sei(); - // FAN tacho input (enable Pull-Up) - DDRD &= ~(1<<PD4); - PORTD |= (1<<PD4); - // rotary encoder DDRB &= ~((1<<PB4) | (1<<PB5)); PORTB |= (1<<PB4) | (1<<PB5); |