nRF9160 RX interrupt not triggering after UART disabled and enabled again

[khodidas]

Hi,

I am using ncs 1.0.0 in nRF9160. 

I have enabled UART 2 interrupt during initialization of the uart as below and it works fine. 

    uart = device_get_binding("UART_2");

    uart_irq_callback_set(uart, uart_cb);
    uart_irq_rx_enable(uart);

To reduce the power consumption i need to disable the UART2 when it is not needed. 

I have disabled the UART2 as below 

nrf_uarte_disable(NRF_UARTE2);

But when i enable the UART2 I am not getting UART 2 RX interrupt. 

I have enabled the UART 2 as below 

nrf_uarte_enable(NRF_UARTE2);

Can you help me in finding why UART RX interrupt doesn't work after i disable and enable the UART 2. 

Regards,

Smitesh Mali

[Martin Lesund]

Hi Smitesh,

The implementation of this functionality in uart_nrfx_uarte.c is not correct.
You have to stop via TASKS_STOPRX and then wait until you get EVENTS_RXTO, and then you can disable.

Please look at this documentation for more details.

(here is a snippet on how to disable UART RX)

[khodidas]

Hi,

I disabled the UART as below 

NRF_UARTE2_NS->TASKS_STOPRX  = 1;
NRF_UARTE2_NS->TASKS_STOPTX = 1;
while(NRF_UARTE2_NS->EVENTS_RXTO==0);

I enabled it like below 

NRF_UARTE2_NS->TASKS_STARTRX = 1;
NRF_UARTE2_NS->TASKS_STARTTX = 1;

But i observed that current consumption on "power profiler" is around 500 uA. 

When i was turning off the UART 2 using "nrf_uarte_disable(NRF_UARTE2)" i was getting 7 uA current.

am i doing turning off UART 2 correctly ?

Regards,

Smitesh Mali

[Martin Lesund]

Hi Smitesh,
Please try to stop via TASKS_STOPRX and then wait until you get EVENTS_RXTO, and then you can disable UART via the function you did in the first post.

And when you are going to enable UART again you send:

NRF_UARTE2_NS->TASKS_STARTRX = 1;
NRF_UARTE2_NS->TASKS_STARTTX = 1;
and then 

nrf_uarte_enable(NRF_UARTE2);

[khodidas]

Hi,

The method suggested by you creates other random issues.

Like MQTT connection failure and Hard fault. 

Regards,

Smitesh Mali

[Martin Lesund]

Hi Smitesh,
I am very sorry for the delay, but I would assume that you have progressed from this issue (?)

If not please share a code snippet on how you implemented this and some serial log output would be nice.

I would also recommend enabling Debug logs in your application.