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.

[Vidar Berg]

I cannot think of any good explanations as to why it works with UART, but not with the UARTE. Can you try to debug the app and check the peripheral event registers to see which events are set? Maybe EVENTS_ERROR is set instead.