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Software => Software => Topic started by: airman00 on October 11, 2008, 07:27:57 PM

Title: UART on Interupt
Post by: airman00 on October 11, 2008, 07:27:57 PM

Hi ,
How can I have a UART reading be taken on an interrupt ?
Meaning an interrupt on the UART Rx pin will trigger a "uartGetByte" .

I am using the ATmega168 and AVRStudio
EDIT: Found the answer http://www.societyofrobots.com/robotforum/index.php?topic=4886.msg38261#msg38261

EDIT: I still don't know the answer to the question below:

Also , if my transmission on the UART was lets say three bytes : 1 2 3. So the first byte ( 1) would trigger the interrupt to do uartGetByte , but would the uartGetByte capture the "1" byte , or would it skip it and only be able to capture the "2" byte?

Thanks.
Eric

Title: Re: UART on Interupt
Post by: ArcMan on October 11, 2008, 08:28:01 PM

Not an Atmel guy, but it's certainly got to be the same as a PIC...

You'll get the first byte.  That's what the UART interrupt is for.  It means "I have just received a full byte of data over the serial port.  Come and get it.".  "BTW - come and get it before the next full byte arrives or it will be gone."

Title: Re: UART on Interupt
Post by: airman00 on October 11, 2008, 08:31:41 PM

To uart.h , would I just add this  to enable an interrupt on Rx UART?

Code: [Select]

//Enable Transmitter and Receiver and Interrupt on receive complete

UCSRB=(1<<RXEN)|(1<<RXCIE);//|(1<<TXEN);

//enable global interrupts
     sei();

and then add this to be the ISR portion

Code: [Select]

ISR(USART_RXC_vect)
{
   // Code to be executed when the USART receives a byte here
}