fix for "realtime uart" in esp32-hal-uart.c

smartinick · web-flow · commit c5931d194690 · 2018-07-25T11:30:52.000+02:00
if you are doing uart stuff that depends on timing, the original code will leave you in the "blind" (Serial.availabe() reads ZERO) until 112 bytes have been received.
Setting this value to 1 will cause 112 times more interrupts, but still use the buffer and not leave your code blind in regards of timing.
diff --git a/cores/esp32/esp32-hal-uart.c b/cores/esp32/esp32-hal-uart.c
@@ -96,7 +96,8 @@ static void IRAM_ATTR _uart_isr(void *arg)
 void uartEnableInterrupt(uart_t* uart)
 {
     UART_MUTEX_LOCK();
-    uart->dev->conf1.rxfifo_full_thrhd = 112;
+    //uart->dev->conf1.rxfifo_full_thrhd = 112; //original
+    uart->dev->conf1.rxfifo_full_thrhd = 1; //fix for "realtime" uart
     uart->dev->conf1.rx_tout_thrhd = 2;
     uart->dev->conf1.rx_tout_en = 1;
     uart->dev->int_ena.rxfifo_full = 1;
