Hi,
My USART interrupt continuously trips on the RXCIF flag even though there is no data line connected. I am reading both RXDATAL and RXDATAH in the interrupt to reset the flag each time (confirmed that the flag is reset), but it just trips again.
Interrupt:
// Interrupt vector for USART RX
ISR(USART0_RXC_vect)
{
// Store character received
uint8_t tempCharH = USART0.RXDATAH;
uint8_t tempChar = USART0.RXDATAL;
// Counting int
uint8_t i = 0;
// If char is start of a command...
if(tempChar == '$')
{
// Reset position to zero in buffer
strPosition = ctrlString;
// Clear buffer
for (i = 0; i < CTRL_LEN; i++ )
{
ctrlString[i] = 0;
}
}
// If char is end of a command '!'...
if(tempChar == '!')
{
// Set command flag
isCommand = TRUE;
}
// Write character to buffer
*strPosition = tempChar;
// Shift position
strPosition++;
}
Initialization:
// Initialize USART comms
void USART_Init()
{
// Set RX pin to input
PORTA.DIRCLR = PIN2_bm;
// Set BAUD rate
USART0.BAUD = BAUD_REGISTER;
// Set receive complete flag
USART0.CTRLA = USART_RXCIE_bm;
// Turn on RX hardware
USART0.CTRLB = USART_RXEN_bm;
}
Thank you,
Tom
