UART Interruptions

[nestor]

Hello,

I'm trying to develop a program for reading from UART port by interruptions using the library provided with eclipse in:

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#include "mcu/microchip_dspic/inc/ee_uart.h"

I have implemented a callback function but I don't understand how it works. For example, I start the port and then I assign the callback function:

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	EE_uart_init(EE_UART_PORT_1, 57600, EE_UART_BIT_STOP_1 | EE_UART_BIT8_NO, EE_UART_CTRL_SIMPLE);

	EE_uart_set_rx_callback(EE_UART_PORT_1, &UART_Rx_cbk, EE_UART_RX_INT_SINGLE);

Then, I define the callback function like this:

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void UART_Rx_cbk(EE_UINT8 data)
{
	if (data == 0x01)
	{
                // led on
		LATBbits.LATB14 = 1;
	}
	else
	{
                // led off
		LATBbits.LATB14 = 0;
	}
}

Is this the way to use it? Or I have to read the data value from the U1RXREG register? That's how I think of how to implement this second way:

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void UART_Rx_cbk(EE_UINT8 data)
	unsigned short valor;

	if (U1STAbits.OERR)
	{	// Receiver buffer has overflowed

		U1STAbits.OERR = 0;
		return;
	}

	if (U1STAbits.URXDA)
	{ 	// Receiver buffer has data. At least one more character can be read

		valor = U1RXREG & 0x00FF;

		if (valor == 1)
		{
			// LEDs ON
		}
		else
		{
			// LEDs OFF
		}
	}

	// reset RX interrupt flag
	IFS0bits.U1RXIF = 0;
	}

I'm doing well? What is the correct way? Thanks!!

[paolo.gai]

The idea of the driver is that the function is called in the context of an ISR2 every time a character arrives. You should not use any register of the UART inside the callback... the serial driver is supposed to take care of that.

If the serial driver does not take care of that, then it's a bug and if you find any bug a patch is always welcome...

Ciao,

PJ

[nestor]

OK! Thanks! I have configured as you tell me and it works, but it seems that it is only capable to receive only 4 characters. I have configured for setting interrupt flag bit when a single character is received.

The interrupt is actived for the first 4 characters that I send from my PC, and later it isn't actived.

Do you know why can it be? Thanks!

[paolo.gai]

Please check first if the standard demo we ship in the package works fine. There are two you can try:

pic30 / Flex Demo Board / Console Demo

pic30 / Flex Multibus Board / Serial demo

If they do not work, then the problem is in the hardware (check the connections...). If they work, then the problem is in your software (check how these demo works...)

Ciao,

PJ