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Code Issues Releases Wiki Activity

Remove "delay_microseconds_accurate()" and improve systemwide delayMicroseconds() (#2497)

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This commit is contained in:
Carlos Garcia Saura
2021-11-10 04:22:00 +01:00
committed by GitHub
parent 6e5cfac927
commit 875b803483
8 changed files with 25 additions and 30 deletions
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21
esphome/core/helpers.cpp
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@@ -209,17 +209,18 @@ uint8_t crc8(uint8_t *data, uint8_t len) {
return crc;
}
void delay_microseconds_accurate(uint32_t usec) {
if (usec == 0)
return;
if (usec < 5000UL) {
delayMicroseconds(usec);
return;
}
uint32_t start = micros();
while (micros() - start < usec) {
delay(0);
void delay_microseconds_safe(uint32_t us) { // avoids CPU locks that could trigger WDT or affect WiFi/BT stability
auto start = micros();
const uint32_t lag = 5000; // microseconds, specifies the maximum time for a CPU busy-loop.
// it must be larger than the worst-case duration of a delay(1) call (hardware tasks)
// 5ms is conservative, it could be reduced when exact BT/WiFi stack delays are known
if (us > lag) {
delay((us - lag) / 1000UL); // note: in disabled-interrupt contexts delay() won't actually sleep
while (micros() - start < us - lag)
delay(1); // in those cases, this loop allows to yield for BT/WiFi stack tasks
}
while (micros() - start < us) // fine delay the remaining usecs
;
}
uint8_t reverse_bits_8(uint8_t x) {