Should fix compilation error

Author: timkoers

cores/esp32/HardwareSerial.cpp

@@ -86,7 +86,7 @@ void HardwareSerial::updateBaudRate(unsigned long baud)
 // Make sure that the function that the function pointer is pointing to is inside IRAM
 void HardwareSerial::setRXInterrupt(void (*arg)(char c)){
     uartDisableInterrupt(_uart);
-    uartEnableInterrupt(_uart, &arg);
+    uartEnableInterrupt(_uart, arg);
 }
 
 void HardwareSerial::end()

cores/esp32/esp32-hal-uart.c

@@ -87,7 +87,7 @@ static void IRAM_ATTR _uart_isr(void (*arg)(char))
             c = uart->dev->fifo.rw_byte;
             if(arg != NULL){ // Check if an interrupt handler function has been specified
                 // Fully optimized code would not create the queue anymore if an function has been specified as an argument.
-                (*arg)((char*)&c); // There is, call it with c as an parameter. Don't pass it to the queue anymore
+                (*arg)((char)c);
             }else if(uart->queue != NULL)  {
                 xQueueSendFromISR(uart->queue, &c, &xHigherPriorityTaskWoken);
             }