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Asynchronous 1-wire reading #594

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krzbor
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@krzbor krzbor commented Nov 30, 2024

Currently, 1-wire is read synchronously, which means the program is paused for up to 750ms. During this pause, a yield is called, ensuring that WiFi works correctly. However, other issues may arise, such as UART read buffer overflow.
I have modified the code so that everything operates asynchronously.
The previous solution to this problem contained a bug:
if ((DALLASASYNC) && ((unsigned long)(millis() - dallasTimer) > ((1000 * dallasTimerWait) - 1000)) ) {
DS18B20.requestTemperatures(); // get temperatures for next run 1 second before getting the temperatures (async)
}
The author assumed the code would execute only once, while in reality, it was executed multiple times per second before the reading.

Currently, 1-wire is read synchronously, which means the program is paused for up to 750ms. During this pause, a yield is called, ensuring that WiFi works correctly. However, other issues may arise, such as UART read buffer overflow.
I have modified the code so that everything operates asynchronously.
The previous solution to this problem contained a bug:
  if ((DALLASASYNC) && ((unsigned long)(millis() - dallasTimer) > ((1000 * dallasTimerWait) - 1000)) ) {
    DS18B20.requestTemperatures(); // get temperatures for next run 1 second before getting the temperatures (async)
  }
The author assumed the code would execute only once, while in reality, it was executed multiple times per second before the reading.
@IgorYbema
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Thanks for finding that bug. I added ASYNC before indeed but I remember I didn't get the result I was expecting back then and forget about bughunting later. I'll review the code.

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2 participants