static void configure(void)
{
_params.timing_advance_deg64 = config_get("motor_timing_advance_deg") * 64 / 60;
_params.motor_bemf_window_len_denom = config_get("motor_bemf_window_len_denom");
_params.bemf_valid_range_pct128 = config_get("motor_bemf_valid_range_pct") * 128 / 100;
_params.zc_failures_max = config_get("motor_zc_failures_to_stop");
_params.zc_detects_min = config_get("motor_zc_detects_to_start");
_params.comm_period_max = config_get("motor_comm_period_max_usec") * HNSEC_PER_USEC;
_params.comm_blank_hnsec = config_get("motor_comm_blank_usec") * HNSEC_PER_USEC;
_params.spinup_timeout = config_get("motor_spinup_timeout_ms") * HNSEC_PER_MSEC;
_params.spinup_start_comm_period = config_get("motor_spinup_start_comm_period_usec") * HNSEC_PER_USEC;
_params.spinup_end_comm_period = config_get("motor_spinup_end_comm_period_usec") * HNSEC_PER_USEC;
_params.spinup_num_good_comms = config_get("motor_spinup_num_good_comms");
_params.spinup_duty_cycle_increment = config_get("motor_spinup_duty_cycle_inc");
/*
* Validation
*/
if (_params.comm_period_max > motor_timer_get_max_delay_hnsec()) {
_params.comm_period_max = motor_timer_get_max_delay_hnsec();
}
if (_params.spinup_end_comm_period > _params.comm_period_max) {
_params.spinup_end_comm_period = _params.comm_period_max;
}
_params.adc_sampling_period = motor_adc_sampling_period_hnsec();
lowsyslog("Motor: RTCTL config: Max comm period: %u usec, BEMF window denom: %i\n",
(unsigned)(_params.comm_period_max / HNSEC_PER_USEC),
_params.motor_bemf_window_len_denom);
}
static int init_constants(unsigned frequency)
{
assert_always(_pwm_top == 0); // Make sure it was not initialized already
/*
* PWM top, derived from frequency
*/
if (frequency < MOTOR_PWM_MIN_FREQUENCY || frequency > MOTOR_PWM_MAX_FREQUENCY) {
return -1;
}
const int pwm_steps = PWM_TIMER_FREQUENCY / frequency;
if ((pwm_steps < 2) || (pwm_steps > 65536)) {
assert(0);
return -1;
}
_pwm_top = pwm_steps - 1;
_pwm_half_top = pwm_steps / 2;
const int effective_steps = pwm_steps / 2;
const float true_frequency = PWM_TIMER_FREQUENCY / (float)pwm_steps;
const unsigned adc_period_usec = motor_adc_sampling_period_hnsec() / HNSEC_PER_USEC;
lowsyslog("Motor: PWM freq: %f; Effective steps: %i; ADC period: %u usec\n",
true_frequency, effective_steps, adc_period_usec);
/*
* PWM min - Limited by MOTOR_ADC_SAMPLE_WINDOW_NANOSEC
*/
const float pwm_clock_period = 1.f / PWM_TIMER_FREQUENCY;
const float pwm_adc_window_len = (MOTOR_ADC_SAMPLE_WINDOW_NANOSEC / 1e9f) * 2;
const float pwm_adc_window_ticks_float = pwm_adc_window_len / pwm_clock_period;
assert(pwm_adc_window_ticks_float >= 0);
uint16_t pwm_half_adc_window_ticks = (uint16_t)pwm_adc_window_ticks_float;
if (pwm_half_adc_window_ticks > _pwm_half_top) {
pwm_half_adc_window_ticks = _pwm_half_top;
}
_pwm_min = pwm_half_adc_window_ticks;
assert(_pwm_min <= _pwm_half_top);
/*
* ADC synchronization.
* ADC shall be triggered in the middle of a PWM cycle in order to catch the moment when the instant
* winding current matches with average winding current - this helps to eliminate the current ripple
* caused by the PWM switching. Thus we trigger ADC at the point ((pwm_value / 2) - adc_advance).
* Refer to "Synchronizing the On-Chip Analog-to-Digital Converter on 56F80x Devices" for some explanation.
*/
const float adc_trigger_advance = MOTOR_ADC_SYNC_ADVANCE_NANOSEC / 1e9f;
const float adc_trigger_advance_ticks_float = adc_trigger_advance / pwm_clock_period;
assert(adc_trigger_advance_ticks_float >= 0);
assert(adc_trigger_advance_ticks_float < (_pwm_top * 0.4f));
_adc_advance_ticks = (uint16_t)adc_trigger_advance_ticks_float;
lowsyslog("Motor: PWM range [%u; %u], ADC advance ticks %u\n",
(unsigned)_pwm_min, (unsigned)_pwm_top, (unsigned)_adc_advance_ticks);
return 0;
}
uint32_t motor_rtctl_get_min_comm_period_hnsec(void)
{
// Ensure some number of ADC samples per comm period
uint32_t retval = motor_adc_sampling_period_hnsec() * 5;
if (retval < ABS_MIN_COMM_PERIOD_USEC * HNSEC_PER_USEC) {
retval = ABS_MIN_COMM_PERIOD_USEC * HNSEC_PER_USEC;
}
return retval;
}
