I generate a waveform to control NeoPixels with success into a simple peripheral project like "Blinky". When I try to do the same into Blinky Client project I got some random delay even by commenting stack initialization.
GOOD SIGNAL:
WRONG SIGNAL:
int main(void)
{
neopixel_strip_t m_strip;
volatile uint8_t dig_pin_num = NRF_GPIO_PIN_MAP(0,21);
volatile uint8_t leds_per_strip = 12;
volatile uint8_t error;
volatile uint8_t led_to_enable = 0;
volatile uint8_t red = 28;
volatile uint8_t green = 0;
volatile uint8_t blue = 28;
NRF_P0->PIN_CNF[21] = ((uint32_t)GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos)
| ((uint32_t)GPIO_PIN_CNF_INPUT_Disconnect << GPIO_PIN_CNF_INPUT_Pos)
| ((uint32_t)GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
| ((uint32_t)GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
| ((uint32_t)GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos);
neopixel_init(&m_strip, dig_pin_num, leds_per_strip);
neopixel_show(&m_strip);
// Enter main loop.
while(1)
{
}
}
//These defines are timed specific to a series of if statements and will need to be changed
//to compensate for different writing algorithms than the one in neopixel.c
#define NEOPIXEL_SEND_ONE NRF_P0->OUTSET = (uint32_t)(GPIO_OUTSET_PIN21_High << GPIO_OUTSET_PIN21_Pos); \
__ASM ( \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
); \
NRF_P0->OUTCLR = (uint32_t)(GPIO_OUTCLR_PIN21_High << GPIO_OUTCLR_PIN21_Pos); \
__ASM ( \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
);
#define NEOPIXEL_SEND_ZERO NRF_P0->OUTSET = (uint32_t)(1UL << GPIO_OUTSET_PIN21_Pos); \
__ASM ( \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
); \
NRF_P0->OUTCLR = (uint32_t)(1UL << GPIO_OUTCLR_PIN21_Pos); \
__ASM ( \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
" NOP\n\t" \
);
void neopixel_show(neopixel_strip_t *strip)
{
const uint8_t PIN = strip->pin_num;
NRF_P0->OUTCLR = (uint32_t)(1UL << GPIO_OUTCLR_PIN21_Pos);
//NRF_P0->OUTSET = (uint32_t)(1UL << GPIO_OUTSET_PIN23_Pos);
// NRF_GPIO->OUTSET = (1UL << PIN);
nrf_delay_us(50);
for (int i = 0; i < strip->num_leds; i++)
{
for (int j = 0; j < 3; j++)
{
if ((strip->leds[i].grb[j] & 128) > 0){
NEOPIXEL_SEND_ONE
}
else{
NEOPIXEL_SEND_ZERO
}
if ((strip->leds[i].grb[j] & 64) > 0) {NEOPIXEL_SEND_ONE}
else {NEOPIXEL_SEND_ZERO}
if ((strip->leds[i].grb[j] & 32) > 0) {NEOPIXEL_SEND_ONE}
else {NEOPIXEL_SEND_ZERO}
if ((strip->leds[i].grb[j] & 16) > 0) {NEOPIXEL_SEND_ONE}
else {NEOPIXEL_SEND_ZERO}
if ((strip->leds[i].grb[j] & 8) > 0) {NEOPIXEL_SEND_ONE}
else {NEOPIXEL_SEND_ZERO}
if ((strip->leds[i].grb[j] & 4) > 0) {NEOPIXEL_SEND_ONE}
else {NEOPIXEL_SEND_ZERO}
if ((strip->leds[i].grb[j] & 2) > 0) {NEOPIXEL_SEND_ONE}
else {NEOPIXEL_SEND_ZERO}
if ((strip->leds[i].grb[j] & 1) > 0) {NEOPIXEL_SEND_ONE}
else {NEOPIXEL_SEND_ZERO}
}
}
}
Do you know where this instability comes from ?
