Fan Controller w/tiny15
A fan controller for my CarAmps noisy 12v Fan.
A fan controller for my CarAmps noisy 12v Fan.
| CODE |
; PWM fan Control with NTC ; ; Written by Roger Storvik (roger.storvik@gmail.com) ; ; v0.1 - works on my breadboard ; ; Fan connected to +12V and Collector on 2n2219 ; Base on 2n2219 connected to PB1 on tiny15 through 3,3K resistor ; Emitter connected to GND ; ; NTC 10K connected to 5V and PB2 ; 5K resistor connected to PB2 and GND .include "tn15def.inc" ;.include "4433def.inc" .def temp=r16 .def tempL=r17 .def tempH=r18 .def fanStopped=r19 .def dlyV1=r20 .def dlyV2=r21 .def dlyV3=r22 .cseg ldi temp,RAMEND out spl,temp clr fanStopped; We assume when reset, fan has been stopped clr temp out tccr1,temp ;out tccr1a,temp ;out tccr1b,temp out tcnt1,temp ;out tcnt1h,temp ;out tcnt1l,temp ;out ocr1h,temp ;out ocr1l,temp out ocr1a,temp ; Set PWM Output ;ldi temp,0x81; Non-Inverting PWM, 8-bit ldi temp, (1<<CS13)|(1<<PWM1)|(1<<COM1A1); Non, CK/8 out tccr1,temp ;out tccr1a,temp ;ldi temp,0x02; CK/8 ;out tccr1b,temp ldi temp,0b00000010; output PB1 out ddrb,temp ;ser temp ; full speed ;out ocr1l,temp ;out ocr1al,temp ldi temp, 0x01;Select ADC1/PB2 out ADMUX, temp startconvert: ldi temp, (1<<ADSC) | (1<<ADEN) | (1<<ADPS1) | (1<<ADPS0) ;set ADC prescaler to , 1MHz / 8 = 125kHz out ADCSR, temp convert: in temp, ADCSR andi temp, (1<<ADIF) breq convert in tempL, ADCL ;IT LOOKS LIKE YOU HAVE TO READ ADCL BEFORE ADCH in tempH, ADCH cpi tempH, 0x02; Check if we have overtemperature brsh fullspeed cpi fanStopped, 0x00 brne notstopped cpi tempL, 0x40; Check if we have lowtemp, from stopped brlo shutfan rjmp middle notstopped: cpi tempL, 0x36; Check if we have lowtemp, not stopped brlo shutfan middle: cpi tempL, 0x60; Check if we have measured something in the middle brsh regtemp ldi temp, 0x60; Set speed to this if we are between reg & lowtemp rjmp checkstop regtemp: mov temp, tempL; Use ADCL to regulate Fan rjmp checkstop shutfan: clr temp ; Stop fan clr fanStopped rjmp checkstop fullspeed: ser temp ; Full speed checkstop: cpi fanStopped, 0x00; Do we have stop command? brne setspeed cpi temp, 0x00 ; Was the fan already stopped? breq stoppit ; No, the fan was stopped ; Run it at full speed a short time ser temp ; Full speed out ocr1a, temp ; out ocr1l, temp ser fanStopped rcall long_dly; Run for a while rjmp startconvert stoppit: rcall long_dly setspeed: out ocr1a, temp ; out ocr1l, temp rjmp startconvert long_dly: ldi dlyV3,0x20 long_dly1: rcall dly dec dlyV3 brne long_dly1 ret dly: ser dlyV1 dly1: ser dlyV2 dly2: dec dlyV2 brne dly2 dec dlyV1 brne dly1 ret |