User guide

AVR1607

8311A-AVR-07/10

duty_cycle = mc_control_current(mc_get_potentiometer_value())

5.4 Commutation

The phase commutation has to be achieved according to the 3 Hall sensors.

Commutation between steps is achieved when a rising or falling edge occurs on one

of the 3 Hall sensor signals.

Hall sensor signals H1/H2/H3 are connected to PE0/PE1/PE2 which are configured

as interrupt sources.

(Another solution could be using internal comparators to generate interrupts.)

Port Interrupt 0 Mask is defined as :

sfrb PORTE_INT0MASK = 0x068A

Are also defined :

#define PORTE_INT0MASK PORTE.INT0MASK

PORTE.INT0MASK = (PIN0_bm | PIN1_bm | PIN2_bm);

This means that PORTE_INT0_vect (HALL-A()) is executed if any of the three Hall

senor signal is changing.

This interrupt vector executes :

• The transistor commutation according to the HALL_SENSOR_VALUE :

HALL_SENSOR_VALUE is the value of the 3 Hall sensor bits = PORTE.IN & 0x07

The commutation is achieved by the function :

mc_switch_commutation(HALL_SENSOR_VALUE)

• and estimation of speed on Rising edge of H1 (Hall A) sensor. This means the

speed is evaluated one time per electrical cycle.

5.4.1 mc_switch_commutation()

This fun

ction achieves two operations:

• First,the update of the duty-cycle, thanks to function

:mc_duty_cycle(mc_get_Duty_Cycle())

This is achieved with the update of the Output new compare value of the Timer:

TC_SetCompareA( &TCC0, level ); which updates CCABUF register with new

compare value

TC_SetCompareB( &TCC0, level );

TC_SetCompareC( &TCC0, level );

The dead time insertion is achieved with ConfigDTI() function which configures a

dead Time both sides equal to 3.