UARTE Interrupt is not working at all

[jswcomkr]

Hi.

I'm developing application that is needed to include  UARTE Interrupt.

I can drive UART interrupt well(not UARTE), but UARTE is not working.

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "nrf_delay.h"
#include "nrf_gpio.h"
#include "nrf_uarte.h"
#include "SEGGER_RTT.h"


void UARTE0_UART0_IRQHandler(){
	SEGGER_RTT_printf(0, "test\n");
    if(NRF_UARTE0->EVENTS_ENDRX){
		SEGGER_RTT_printf(0, "test\n");
    }

}

int main(void)
{

	static uint8_t txBuffer[7] = "TEST\r\n";
	static uint8_t rxBuffer[20] = {0};

    NRF_UARTE0->BAUDRATE = NRF_UARTE_BAUDRATE_9600;
    NRF_UARTE0->PSEL.TXD = 19;
    NRF_UARTE0->PSEL.RXD = 18;
    NRF_UARTE0->CONFIG = NRF_UARTE_HWFC_DISABLED;
    NRF_UARTE0->ENABLE = (UARTE_ENABLE_ENABLE_Enabled << UARTE_ENABLE_ENABLE_Pos);

    NRF_UARTE0->TXD.PTR = (uint32_t)((uint8_t *) txBuffer);
    NRF_UARTE0->TXD.MAXCNT = sizeof(txBuffer);
    NRF_UARTE0->TASKS_STARTTX = 0;

    NRF_UARTE0->RXD.PTR = (uint32_t)((uint8_t *) rxBuffer);
    NRF_UARTE0->RXD.MAXCNT = sizeof(rxBuffer);
    NRF_UARTE0->TASKS_STARTRX = 1;


    //NRF_UARTE0->INTENCLR = 0xFFFFFFFF;
    NRF_UARTE0->INTENSET = (1 << 2);

    NVIC_ClearPendingIRQ(UARTE0_UART0_IRQn);
    NVIC_SetPriority(UARTE0_UART0_IRQn, 5);
    NVIC_EnableIRQ(UARTE0_UART0_IRQn);


    SEGGER_RTT_printf(0, "teTN\n");
    while (true)
    {
    	NRF_UARTE0->TASKS_STARTTX;
    }
}

Here is my code. Would guide me please?

Thank you.

[Dmitry]

Hi,

there are some points to fix:

    if(NRF_UARTE0->EVENTS_ENDRX){
		SEGGER_RTT_printf(0, "test\n");
    }

you need to clear EVENTS_ENDRX here.

NRF_UARTE0->INTENSET = (1 << 2);

This will enable RXDRDY interrupt, not ENDRX. It's always better to use named constants.

NRF_UARTE0->TASKS_STARTTX;

this does nothing, should be NRF_UARTE0->TASKS_STARTTX = 1  (and wait for ENDTX event before next write)

[jswcomkr]

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "nrf_delay.h"
#include "nrf_gpio.h"
#include "nrf_uarte.h"
#include "SEGGER_RTT.h"


void UARTE0_UART0_IRQHandler(){
	SEGGER_RTT_printf(0, "test\n");
    if(NRF_UARTE0->EVENTS_ENDRX == 1){
		SEGGER_RTT_printf(0, "test\n");
		NRF_UARTE0->EVENTS_ENDRX = 0;
    }
    if(NRF_UARTE0->EVENTS_RXDRDY == 1){
    	SEGGER_RTT_printf(0, "RXDRDY\n");
    	NRF_UARTE0->EVENTS_RXDRDY = 0;
    }

}

int main(void)
{

	static uint8_t txBuffer[7] = "TEST\r\n";
	static uint8_t rxBuffer[20] = {0};

    NRF_UARTE0->BAUDRATE = NRF_UARTE_BAUDRATE_9600;
    NRF_UARTE0->PSEL.TXD = 6;
    NRF_UARTE0->PSEL.RXD = 8;
    NRF_UARTE0->CONFIG = NRF_UARTE_HWFC_DISABLED;
    NRF_UARTE0->ENABLE = (UARTE_ENABLE_ENABLE_Enabled << UARTE_ENABLE_ENABLE_Pos);

    NRF_UARTE0->TXD.PTR = (uint32_t)((uint8_t *) txBuffer);
    NRF_UARTE0->TXD.MAXCNT = sizeof(txBuffer);
    NRF_UARTE0->TASKS_STARTTX = 0;

    NRF_UARTE0->RXD.PTR = (uint32_t)((uint8_t *) rxBuffer);
    NRF_UARTE0->RXD.MAXCNT = sizeof(rxBuffer);
    NRF_UARTE0->TASKS_STARTRX = 1;


    //NRF_UARTE0->INTENCLR = 0xFFFFFFFF;
    NRF_UARTE0->INTENSET = (1 << 4);

    NVIC_ClearPendingIRQ(UARTE0_UART0_IRQn);
    NVIC_SetPriority(UARTE0_UART0_IRQn, 5);
    NVIC_EnableIRQ(UARTE0_UART0_IRQn);

    NRF_UARTE0->TASKS_STARTTX = 0x01;
    while(!NRF_UARTE0->EVENTS_TXSTARTED){}


    SEGGER_RTT_printf(0, "Sequence check\n");
    while (true)
    {


    }
}

I've changed my code. But it is not works at all.

Normal reading is fine. Only the problem is Interrupt.

UARTE0_UART0_IRQHandler() <- This code is not called at all.

[Vidar Berg]

Hello,

You must send RXD.MAXCNT(20) bytes for the ENDRX event to trigger the interrupt, did you try that?

[jswcomkr]

Hi.

NRF_UARTE0->INTENSET = (1 << 4) | (1 << 2);

I modified this code.

But there is no response. I've double checked TX, and RX pin number.

What is the problems?

[Vidar Berg]

Are you testing with a nordic dev kit? Your code works when I try it here. The only change I made was to remove the RTT calls.

Hitting breakpoint after receiving 1 byte:

[jswcomkr]

Can you check Interrupt? UARTE0_UART0_IRQHandler isn't called.

[Vidar Berg]

As you can see from the screenshot I posted, the program enters the interrupt handler in my case.

[jswcomkr]

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "nrf_delay.h"
#include "nrf_gpio.h"
#include "nrf_uarte.h"
#include "SEGGER_RTT.h"


void UARTE0_UART0_IRQHandler(){
	SEGGER_RTT_printf(0, "test\n");
    if(NRF_UARTE0->EVENTS_ENDRX == 1){
		SEGGER_RTT_printf(0, "test\n");
		NRF_GPIO->OUTCLR = (1 << 23);
		NRF_UARTE0->EVENTS_ENDRX = 0;
    }
    if(NRF_UARTE0->EVENTS_RXDRDY == 1){
    	SEGGER_RTT_printf(0, "RXDRDY\n");
    	NRF_GPIO->OUTCLR = (1 << 23);
    	NRF_UARTE0->EVENTS_RXDRDY = 0;
    }

}

int main(void)
{
	NRF_GPIO->DIRSET = (1 << 23);
	NRF_GPIO->OUTSET = (1 << 23);
	static uint8_t txBuffer[7] = "TEST\r\n";
	static uint8_t rxBuffer[20] = {0};

    NRF_UARTE0->BAUDRATE = NRF_UARTE_BAUDRATE_9600;
    NRF_UARTE0->PSEL.TXD = 6;
    NRF_UARTE0->PSEL.RXD = 8;
    NRF_UARTE0->CONFIG = NRF_UARTE_HWFC_DISABLED;
    NRF_UARTE0->ENABLE = (UARTE_ENABLE_ENABLE_Enabled << UARTE_ENABLE_ENABLE_Pos);

    NRF_UARTE0->TXD.PTR = (uint32_t)((uint8_t *) txBuffer);
    NRF_UARTE0->TXD.MAXCNT = sizeof(txBuffer);
    NRF_UARTE0->TASKS_STARTTX = 0;

    NRF_UARTE0->RXD.PTR = (uint32_t)((uint8_t *) rxBuffer);
    NRF_UARTE0->RXD.MAXCNT = 5;
    NRF_UARTE0->TASKS_STARTRX = 1;


    //NRF_UARTE0->INTENCLR = 0xFFFFFFFF;
    NRF_UARTE0->INTENSET = (1 << 4) | (1 << 2);

    NVIC_ClearPendingIRQ(UARTE0_UART0_IRQn);
    NVIC_SetPriority(UARTE0_UART0_IRQn, 6);
    NVIC_EnableIRQ(UARTE0_UART0_IRQn);

    NRF_UARTE0->TASKS_STARTTX = 0x01;
    while(!NRF_UARTE0->EVENTS_TXSTARTED){}

    uint8_t i=0;
    SEGGER_RTT_printf(0, "Sequence check\n");
    while (true)
    {
    	if(NRF_UARTE0->EVENTS_RXDRDY == 1){
    		SEGGER_RTT_printf(0, "Test %d : %d, %d\n", i++, rxBuffer[0], rxBuffer[1]);
    		NRF_UARTE0->EVENTS_RXDRDY = 0;
    	}
    	if(NRF_UARTE0->EVENTS_ENDRX == 1){
    		SEGGER_RTT_printf(0, "END RX Event!!!\n");
    		NRF_GPIO->OUTCLR = (1 << 23);
    		memset(rxBuffer, 0, sizeof(rxBuffer));
    		NRF_UARTE0->EVENTS_ENDRX = 0;
    	}
    	if(i >= 5){
    		i = 0;
    	}

    }
}

I can't get any data from RTT viewer.

What did I do wrong?

*Modiefied attatched code.

[Vidar Berg]

I think it could be HW related seeing that the same code worked on my side. Were you testing this on a nordic or custom board? Are you using the Segger IC as the USB - UART bridge?

[jswcomkr]

It is custom board. I use cp2104 as uart bridge. I can use normal UART interrupt, but the problems only happens when I use UARTE.