Dear,
I need to generate a pulse signal on one IO following this pattern:
HIGH for 12us ; LOW for 106us ; and so on...
I tried to use TIMER0 with NRF_TIMER_EVENT_COMPARE0 and NRF_TIMER_EVENT_COMPARE1 but the signal is often not respected (keeping one cycle the IO HIGH also during second period). So I assume I need to use dppi, but using the following code, I still not see anything happening on the io:
struct gpio_dt_spec mofset_ctrl_io = GPIO_DT_SPEC_GET(DT_NODELABEL(mofset_ctrl), gpios);
#define TIMER_INSTANCE_NUMBER 0
const nrfx_timer_t timer_instance = NRFX_TIMER_INSTANCE(TIMER_INSTANCE_NUMBER);
#define TOGGLE_INTERVAL_ON_US 12
#define TOGGLE_INTERVAL_OFF_US 106
static nrfx_gpiote_t const gpiote_inst = NRFX_GPIOTE_INSTANCE(0);
static uint8_t dppi_channel;
static void timer0_init(void)
{
nrfx_err_t err;
nrfx_timer_config_t timer_config = NRFX_TIMER_DEFAULT_CONFIG(16000000);
timer_config.bit_width = NRF_TIMER_BIT_WIDTH_16;
err = nrfx_timer_init(&timer_instance, &timer_config, NULL);
if (err != NRFX_SUCCESS) {
LOG_ERR("nrfx_timer_init error: %08x", err);
return;
}
uint32_t ticks1 = nrfx_timer_us_to_ticks(&timer_instance, TOGGLE_INTERVAL_ON_US);
uint32_t ticks2 = nrfx_timer_us_to_ticks(&timer_instance, TOGGLE_INTERVAL_ON_US + TOGGLE_INTERVAL_OFF_US);
LOG_INF("COMPARE0: %d ticks, COMPARE1: %d ticks", ticks1, ticks2);
nrfx_timer_extended_compare(
&timer_instance,
NRF_TIMER_CC_CHANNEL0,
ticks1,
NRF_TIMER_SHORT_COMPARE1_CLEAR_MASK, // Efface le compteur après COMPARE1
true
);
nrfx_timer_extended_compare(
&timer_instance,
NRF_TIMER_CC_CHANNEL1,
ticks2,
NRF_TIMER_SHORT_COMPARE1_CLEAR_MASK, // On efface à COMPARE1
true
);
// Connexion de l'IRQ
IRQ_DIRECT_CONNECT(TIMER0_IRQn, 0, nrfx_timer_0_irq_handler, 0);
irq_enable(TIMER0_IRQn);
nrfx_timer_enable(&timer_instance);
LOG_INF("Timer started");
}
static void gpiote_dppi_init(void)
{
nrfx_err_t err;
err = nrfx_gpiote_init(&gpiote_inst, NRFX_GPIOTE_DEFAULT_CONFIG_IRQ_PRIORITY);
if (err != NRFX_SUCCESS && err != NRFX_ERROR_ALREADY_INITIALIZED) {
LOG_ERR("nrfx_gpiote_init error: %08x", err);
return;
}
nrfx_gpiote_output_config_t gpiote_config = NRFX_GPIOTE_DEFAULT_OUTPUT_CONFIG;
err = nrfx_gpiote_output_configure(&gpiote_inst, mofset_ctrl_io.pin, &gpiote_config, NULL);
if (err != NRFX_SUCCESS) {
LOG_ERR("nrfx_gpiote_output_configure error: %08x", err);
return;
}
nrfx_gpiote_trigger_enable(&gpiote_inst, mofset_ctrl_io.pin, true);
err = nrfx_dppi_channel_alloc(&dppi_channel);
if (err != NRFX_SUCCESS) {
LOG_ERR("nrfx_dppi_channel_alloc error: %08x", err);
return;
}
nrfx_gppi_channel_endpoints_setup(dppi_channel,
nrfx_timer_compare_event_address_get(&timer_instance, NRF_TIMER_CC_CHANNEL0),
nrfx_gpiote_out_task_address_get(&gpiote_inst, mofset_ctrl_io.pin));
nrfx_gppi_channel_endpoints_setup(dppi_channel,
nrfx_timer_compare_event_address_get(&timer_instance, NRF_TIMER_CC_CHANNEL1),
nrfx_gpiote_out_task_address_get(&gpiote_inst, mofset_ctrl_io.pin));
err = nrfx_dppi_channel_enable(dppi_channel);
if (err != NRFX_SUCCESS) {
LOG_ERR("Failed to enable DPPI channel, error: %08x", err);
return;
}
LOG_INF("GPIOTE + DPPI initialized");
}
Do you know why ? I confess it was difficult to setup this with all the API changes on that topic (add of nrfx_gpiote_t in prototypes and other changes), and I never found one full example working for nrf5340 and NCS 2.7.0 I am using.
Thanks in advance for your piece of advice!
Kind regards,
Michael
