Hi,
I got strange error which I can't to fix.
From time to time, I get the same readings from every function which counts the CPU cycles.
They all base on DWT_CTRL.
Board is clocked with 64Mhz, OS is clocked with NRF_RTC_TIMER.
When I execute multiple times a function like this `k_cycle_get_32`, I get the same reading until the thread locks itself again.
I receive SPI data every 250us, so there should be no problems with this, if the CPU is clocked with a few MHz.
My thread looks like this:
void ads129x_th(void)
{
/* setup ecg */
ads129x_setup();
for (;;)
{
/*
* Wait for semaphore from ISR; if acquired, do related work, then
* go to next loop iteration (the semaphore might have been given
* again); else, make the CPU idle.
*/
if (k_sem_take(&ads129x_new_data, K_FOREVER) == 0)
{
/* track status of buffers */
static size_t bytes_written = 0;
/* add timestamp */
uint32_t end_time = k_cycle_get_32();
return conv_u24_to_raw(k_cyc_to_us_ceil32(end_time), tx_data.buffer, 0);
/* do processing */
/* NOTE: Work directly on a ring buffer memory */
int ret = spi_read(ads129x_config.ads129x_spi, &ads129x_config.ads129x_spi_cfg, &ads129x_rx);
if (!ret)
{
/* add missing leads */
ads129x_load_augmented_leads(tx_data.packet.leads._buffer);
ads129x_dump_data(tx_data.packet.leads._buffer);
/* send data to the consumers */
k_pipe_put(&ads129x_pipe, &tx_data.buffer, ADS129x_DATA_BUFFER_SIZE, &bytes_written, sizeof(pipe_packet_u), K_NO_WAIT);
}
}
}
}
I tried:
⇾ using base k_cycle_get_32
→ using timing functions
→ using Cortex M systick with different clock speed
CONFIG_NRF_RTC_TIMER=n CONFIG_CORTEX_M_SYSTICK=y CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=64000000 CONFIG_SYS_CLOCK_TICKS_PER_SEC=6400000
All of them are broken.
Could somebody help me :D
