static bool do_bemf_spinup(const float max_duty_cycle)
{
assert(chThdGetPriority() == HIGHPRIO); // Mandatory
// Make sure we're not going to underflow during time calculations
while (motor_timer_hnsec() < _params.spinup_start_comm_period) {
;
}
const uint64_t deadline = motor_timer_hnsec() + _params.spinup_timeout;
float dc = _params.spinup_duty_cycle_increment;
unsigned num_good_comms = 0;
_state.comm_period = _params.spinup_start_comm_period;
_state.prev_zc_timestamp = motor_timer_hnsec() - _state.comm_period / 2;
_state.pwm_val = motor_pwm_compute_pwm_val(dc);
while (motor_timer_hnsec() <= deadline) {
// Engage the current comm step
irq_primask_disable();
motor_pwm_set_step_from_isr(_state.comm_table + _state.current_comm_step, _state.pwm_val);
irq_primask_enable();
uint64_t step_deadline = motor_timer_hnsec() + _state.comm_period;
motor_timer_hndelay(_params.comm_blank_hnsec);
// Wait for the next zero crossing
const uint64_t zc_timestamp = spinup_wait_zc(step_deadline);
num_good_comms = (zc_timestamp > 0) ? (num_good_comms + 1) : 0;
// Compute the next duty cycle
dc += _params.spinup_duty_cycle_increment;
if (dc > max_duty_cycle) {
dc = max_duty_cycle;
}
_state.pwm_val = motor_pwm_compute_pwm_val(dc);
if (zc_timestamp > 0) {
assert(zc_timestamp > _state.prev_zc_timestamp);
// Update comm period
const uint32_t new_comm_period = zc_timestamp - _state.prev_zc_timestamp;
_state.prev_zc_timestamp = zc_timestamp;
_state.comm_period = (_state.comm_period + new_comm_period) / 2;
step_deadline = zc_timestamp + _state.comm_period / 2;
// Check the termination condition
const bool enough_good_comms = num_good_comms > _params.spinup_num_good_comms;
const bool fast_enough = _state.comm_period <= _params.spinup_end_comm_period;
if (enough_good_comms || fast_enough) {
break;
}
} else {
// If ZC was not detected, we need to fake the previous ZC timestamp now
_state.prev_zc_timestamp = step_deadline - _state.comm_period / 2;
}
// Wait till the end of the current step
while (motor_timer_hnsec() <= step_deadline) {
;
}
// Next step
_state.current_comm_step++;
if (_state.current_comm_step >= MOTOR_NUM_COMMUTATION_STEPS) {
_state.current_comm_step = 0;
}
}
return _state.comm_period < _params.comm_period_max;
}
void motor_pwm_beep(int frequency, int duration_msec)
{
static const float DUTY_CYCLE = 0.01;
static const int ACTIVE_USEC_MAX = 20;
motor_pwm_set_freewheeling();
frequency = (frequency < 100) ? 100 : frequency;
frequency = (frequency > 5000) ? 5000 : frequency;
duration_msec = (duration_msec < 1) ? 1 : duration_msec;
duration_msec = (duration_msec > 5000) ? 5000 : duration_msec;
/*
* Timing constants
*/
const int half_period_hnsec = (HNSEC_PER_SEC / frequency) / 2;
int active_hnsec = half_period_hnsec * DUTY_CYCLE;
if (active_hnsec > ACTIVE_USEC_MAX * HNSEC_PER_USEC) {
active_hnsec = ACTIVE_USEC_MAX * HNSEC_PER_USEC;
}
const int idle_hnsec = half_period_hnsec - active_hnsec;
const uint64_t end_time = motor_timer_hnsec() + duration_msec * HNSEC_PER_MSEC;
/*
* FET round robin
* This way we can beep even if some FETs went bananas
*/
static unsigned _phase_sel;
const int low_phase_first = _phase_sel++ % MOTOR_NUM_PHASES;
const int low_phase_second = _phase_sel++ % MOTOR_NUM_PHASES;
const int high_phase = _phase_sel++ % MOTOR_NUM_PHASES;
_phase_sel++; // We need to increment it not by multiple of 3
assert(low_phase_first != high_phase && low_phase_second != high_phase);
/*
* Commutations
* No high side pumping
*/
phase_set_i(low_phase_first, 0, false);
phase_set_i(low_phase_second, 0, false);
phase_set_i(high_phase, 0, false);
apply_phase_config();
while (end_time > motor_timer_hnsec()) {
chSysSuspend();
irq_primask_disable();
phase_set_i(high_phase, _pwm_top, false);
apply_phase_config();
irq_primask_enable();
motor_timer_hndelay(active_hnsec);
irq_primask_disable();
phase_set_i(high_phase, 0, false);
apply_phase_config();
irq_primask_enable();
chSysEnable();
motor_timer_hndelay(idle_hnsec);
}
motor_pwm_set_freewheeling();
}
