void delta_sigma_start(uint32_t period, uint32_t range, uint8_t pins[],
uint8_t n_pins)
{
// Stop the timer during configuration
timer_set_run(FRC1, false);
g_n_pins = n_pins;
for (uint8_t i = 0; i < n_pins; ++i)
{
g_pins[i].gpio_mask = BIT(pins[i]);
g_pins[i].duty = 0;
g_pins[i].acc = 0;
gpio_enable(pins[i], GPIO_OUTPUT);
}
g_range = range;
timer_set_interrupts(FRC1, false);
timer_set_divider(FRC1, TIMER_CLKDIV_256);
if (period > TIMER_FRC1_MAX_LOAD)
{
printf("delta_sigma: period %u too large\n", period);
period = TIMER_FRC1_MAX_LOAD;
}
timer_set_load(FRC1, period);
timer_set_reload(FRC1, true);
_xt_isr_attach(INUM_TIMER_FRC1, timer_isr, NULL);
timer_set_interrupts(FRC1, true);
timer_set_run(FRC1, true);
}
void user_init(void)
{
uart_set_baud(0, 115200);
/* configure GPIOs */
gpio_enable(gpio_frc1, GPIO_OUTPUT);
gpio_enable(gpio_frc2, GPIO_OUTPUT);
gpio_write(gpio_frc1, 1);
/* stop both timers and mask their interrupts as a precaution */
timer_set_interrupts(FRC1, false);
timer_set_run(FRC1, false);
timer_set_interrupts(FRC2, false);
timer_set_run(FRC2, false);
/* set up ISRs */
_xt_isr_attach(INUM_TIMER_FRC1, frc1_interrupt_handler);
_xt_isr_attach(INUM_TIMER_FRC2, frc2_interrupt_handler);
/* configure timer frequencies */
timer_set_frequency(FRC1, freq_frc1);
timer_set_frequency(FRC2, freq_frc2);
/* unmask interrupts and start timers */
timer_set_interrupts(FRC1, true);
timer_set_run(FRC1, true);
timer_set_interrupts(FRC2, true);
timer_set_run(FRC2, true);
gpio_write(gpio_frc1, 0);
}
void pwm_start()
{
pwmInfo._onLoad = pwmInfo.dutyCicle * pwmInfo._maxLoad / UINT16_MAX;
pwmInfo._offLoad = pwmInfo._maxLoad - pwmInfo._onLoad;
pwmInfo._step = PERIOD_ON;
// Trigger ON
uint8_t i = 0;
for (; i < pwmInfo.usedPins; ++i)
{
gpio_write(pwmInfo.pins[i].pin, true);
}
timer_set_load(FRC1, pwmInfo._onLoad);
timer_set_reload(FRC1, false);
timer_set_interrupts(FRC1, true);
timer_set_run(FRC1, true);
pwmInfo.running = 1;
}
void pwm_stop()
{
timer_set_interrupts(FRC1, false);
timer_set_run(FRC1, false);
pwmInfo.running = 0;
}