kingkevin
/
scale_korona
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

add analog comparator

This commit is contained in:
King Kévin 2015-01-06 16:26:30 +01:00
parent 01dc62a713
commit 97f3283118
2 changed files with 30 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
firmware/main.c
View File

@ -30,7 +30,7 @@
#include "main.h" // main definitions #include "main.h" // main definitions
/* variables */ /* variables */
volatile uint8_t stateD; // the state of port D volatile uint8_t state_portD; // the state of port D
/* switch off LED */ /* switch off LED */
void led_off(void) void led_off(void)
@ -51,30 +51,30 @@ void led_toggle(void)
} }
/* scale on interrupt /* scale on interrupt
PCI2 Interrupt Vector for PCINT[23:16]/PORTD * PCI2 Interrupt Vector for PCINT[23:16]/PORTD
*/ */
ISR(PCINT2_vect) ISR(PCINT2_vect)
{ {
if ((stateD&(1<<SCALE_ON))!=(PIND&(1<<SCALE_ON))) { // scale on state changed if ((state_portD&(1<<SCALE_ON))!=(PIND&(1<<SCALE_ON))) { // scale on state changed
if (PIND&(1<<SCALE_ON)) { if (PIND&(1<<SCALE_ON)) {
led_on(); led_on();
} else { } else {
led_off(); led_off();
} }
} }
stateD = PIND; // save new state state_portD = PIND; // save new state
} }
/* timer 1 OCR1A match interrupt /* PWM weight signal
* use it to toogle LED * analog comparator interrupt
*/ */
ISR(TIMER1_COMPA_vect) ISR(ANALOG_COMP_vect)
{ {
/* if (ACSR&(1<<ACO)) { // PWM high
if (blink_flag) { led_on();
led_toggle(); } else { // PWM low
led_off();
} }
*/
} }
/* disable watchdog when booting */ /* disable watchdog when booting */
@ -99,14 +99,25 @@ void io_init(void)
/* LED */ /* LED */
DDRB |= (1<<LED); // LED is driven by pin (set as output) DDRB |= (1<<LED); // LED is driven by pin (set as output)
led_off(); led_off();
/* scale on signal */ /* scale on signal */
DDRD &= ~(1<<SCALE_ON); // SIGNAL_ON is input (should be per default) DDRD &= ~(1<<SCALE_ON); // SIGNAL_ON is input (should be per default)
PCIFR &= ~(1<<PCIF2); // clear interrupt flag for SCALE_ON on PCINT[23:16]/PORTD PCIFR &= ~(1<<PCIF2); // clear interrupt flag for SCALE_ON on PCINT[23:16]/PORTD
PCICR |= (1<<PCIE2); // enable interrupt for PCINT[23:16]/PORTD PCICR |= (1<<PCIE2); // enable interrupt for PCINT[23:16]/PORTD
PCMSK2 |= (1<<PCINT21); // enable interrupt for SCALE_ON PCMSK2 |= (1<<PCINT21); // enable interrupt for SCALE_ON
stateD = PIND; // save state to detect changes state_portD = PIND; // save state to detect change
/* PWM scale weight signal on analog comparator */ /* PWM scale weight signal on analog comparator */
DDRD &= ~((1<<SCALE_PWM)||(1<<REF_PWM)); // analog comparator is input (should be per default) DDRD &= ~((1<<SCALE_PWM)|(1<<REF_PWM)); // analog comparator is input (should be per default)
ADCSRA &= ~(1<<ADEN); // switch off ADC
ADCSRB &= ~(1<<ACME); // disable analog comparator multiplexer, use AIN1 as negative input (should be per default)
ACSR &= ~(1<<ACD); // enable analog comparator (should be per default)
ACSR &= ~(1<<ACBG); // use AIN0 as positiv input (should be per default)
ACSR |= (1<<ACI); // clear analog comparator interrup flag
ACSR |= (1<<ACIC); // enable analog comparator input capture (on timer 1)
ACSR &= ~((1<<ACIS1)|(1<<ACIS0)); // comparator interrupt on output toggle
DIDR1 |= ((1<<AIN1D)|(1<<AIN0D)); // disable digital input buffer on AIN0 and AIN1
ACSR |= (1<<ACIE); // enable analog comparator interrupt
sei(); /* enable interrupts */ sei(); /* enable interrupts */
} }

9
firmware/main.h
View File

@ -25,15 +25,16 @@
*/ */
#define SCALE_ON PD5 #define SCALE_ON PD5
/* PWM weight signal /* PWM weight signal
* high time defines the weight (propotionnally) * PWM frequency is ~3Hz
* low time is constant * high time increases with increasing weight (propotionnally)
* signal level is 500mV * low time decreases with increasing weight
* signal level is 1V
* positive pin of analog comparator used to measure PWM * positive pin of analog comparator used to measure PWM
* pin: PD6, AIN0, D6 * pin: PD6, AIN0, D6
*/ */
#define SCALE_PWM PD6 #define SCALE_PWM PD6
/* negative pin of analog comparator /* negative pin of analog comparator
* set at 100-400mV using voltage divider * set at 0.2-0.8V using voltage divider
* used to detect PWM signal change * used to detect PWM signal change
* pin: PD7, AIN1, D7 * pin: PD7, AIN1, D7
*/ */