NRF9160 Disable UART and RX pin into an interrupt pin

[Lamdev]

Hello everyone,

I'm working on a project with NRF9160 nRF Connect SDK v2.3.0.

In my project i use UART0 to exchange data and i disable the UART when is not use.

I need an interrupt to wake up my device when data come on the UART pin (TX/RX).

I have found different topic to disable and enable UART on runinng time. 

Now, when my uart is disable, i would like to convert RX pin into an interrupt pin which allow me to re-enable the UART to get data when interrupt occur.

Could you tell me if you have any advice about that ?

Best regards,

Lam

[Lamdev]

I found my error, lin 1, I define SWIN3_NODE and line 6 i use SWIN3. That wrong, i need to write on line 6 : "SWIN3_NODE"

I have add in "configure_int_rx" function, 

if (!device_is_ready(button.port)) {
		printk("Error");
		return;
	}

At the top of the function

//gpio for UART interrupt definition
void configure_int_rx(void){
	int ret;

	printk("configure interrupt\r\n");

	if (!device_is_ready(button.port)) {
		printk("Error");
		return;
	}

	ret = gpio_pin_configure_dt(&button,GPIO_INPUT);
	if (ret != 0) {
		printk("Error");// %d: failed to configure %s pin %d\n",
		      // ret, button.port->name, button.pin);
		return;
	}

	printk("test1\r\n");

	ret = gpio_pin_interrupt_configure_dt(&button,GPIO_INT_EDGE_TO_ACTIVE);		//GPIO_INT_EDGE_BOTH
	if (ret != 0) {
		printk("Error");// %d: failed to configure interrupt on %s pin %d\n",
			//ret, button.port->name, button.pin);
		return;
	}

	printk("test2\r\n");

	gpio_init_callback(&button_cb_data, button_pressed, BIT(button.pin));
	gpio_add_callback(button.port, &button_cb_data);
	printk("Set up button");// at %s pin %d\n", button.port->name, button.pin);
}

No I'm trying to disable, my interrupt to reenable the uart when my interrupt occur.

When my interrupt occur, my callback function do that :

void button_pressed(const struct device *dev, struct gpio_callback *cb,
		    uint32_t pins)
{
	const struct device * gpio_dev = DEVICE_DT_GET(DT_NODELABEL(gpio0));
    gpio_pin_configure(gpio_dev,6, GPIO_DISCONNECTED);
	printk("Button pressed\r\n");
	restart_uart();

}

In my "restart_uart", i do that

uint8_t restart_uart(void){


   const struct device *uart = DEVICE_DT_GET(DT_NODELABEL(uart0));

    if (!device_is_ready(uart)) {
        printk("error device ready\r\n");
        return;
    }
    initControlUart();
    printk("restart uart\r\n");
}

When my initControlUart is executed, i have an error in this code: 

 error = uart_rx_enable(uart_info.dev, buffer, RX_BUFF_LEN, RX_RCV_TIMEOUT);
    if(error != 0){
        printk("ERROR : Unable to init RX\n");
        return -1;
    }

That works great at init but when i try to restart that's not work. It seems that RX gpio stay unable to be configure in RX

Update below

Best regards,

lam

[Lamdev]

I have a better answer now,

void button_pressed(const struct device *dev, struct gpio_callback *cb,
		    uint32_t pins)
{
	int ret;
	ret = gpio_pin_interrupt_configure_dt(&button,GPIO_INT_DISABLE);		//GPIO_INT_EDGE_BOTH
	if (ret != 0) {
		printk("Error disable INT\r\n");
		return;
	}
	printk("Button pressed\r\n");
	restart_uart();

}

uint8_t restart_uart(void){

    NRF_UARTE0_NS->PSEL.RXD = 6;
    NRF_UARTE0_NS->PSEL.TXD = 7;
    NRF_UARTE0_NS->ENABLE = 8;
    NRF_UARTE0_NS->TASKS_STARTRX = 1;
    NRF_UARTE0_NS->TASKS_STARTTX = 1;

    send_uart_data_char("UART RESTARTED\r\n");

    //initControlUart();

    printk("restart uart\r\n");
}

I correctly have an answer from my UART, i correctly receive "UART RESTARTED".

But 2 errors messages stay : 

- ERROR : uart_rx_buf_rsp Failed

- UART_TX_ABORTED

The first one come from uart libray and the other one come from my uart callback function

static void uart_callback(const struct device *dev, struct uart_event *evt, struct uart_info_struct *user_data){
    uint8_t *buffer, error;
	switch(evt->type){
		case UART_RX_RDY:
		    //printk("RCV %d bytes\n", evt->data.rx.len);
            if(user_data->cmd_buffer_len < CMD_BUFF_LEN){
                if((user_data->cmd_buffer_len + evt->data.rx.len) <= CMD_BUFF_LEN){
                    //case of new data less than remaining space in cmd_buffer
                    memcpy(user_data->cmd_buffer + user_data->cmd_buffer_len, evt->data.rx.buf + evt->data.rx.offset, evt->data.rx.len);
                    user_data->cmd_buffer_len += evt->data.rx.len;
                }else{
                    //case of new data more than remaining space
                    memcpy(user_data->cmd_buffer + user_data->cmd_buffer_len, evt->data.rx.buf + evt->data.rx.offset, CMD_BUFF_LEN - user_data->cmd_buffer_len);
                    user_data->cmd_buffer_len += CMD_BUFF_LEN - user_data->cmd_buffer_len;
                }
            }
            process_buffer(user_data);
		break;
		case UART_TX_ABORTED:
		    printk("UART_TX_ABORTED\n");
		break;
		case UART_TX_DONE:
		    //printk("UART_TX_DONE\n");
            //printk("+SEM=%d\n",k_sem_count_get(user_data->tx_semaphore));
            k_sem_give(user_data->tx_semaphore);
            //printk("+SEM=%d\n",k_sem_count_get(user_data->tx_semaphore));
		break;
		case UART_RX_BUF_REQUEST:
            //printk("UART_RX_BUF_REQUEST\n");
            buffer = k_malloc(RX_BUFF_LEN);
            if(buffer == NULL){
                printk("ERROR : RX_BUF_REQUEST Failed to allocate buffer\n");
                return;
            }
            error = uart_rx_buf_rsp(uart_info.dev, buffer, RX_BUFF_LEN);
            if(error != 0){
                printk("ERROR : uart_rx_buf_rsp Failed\n");
                return;
            }
		break;
            case UART_RX_BUF_RELEASED:
            k_free(evt->data.rx_buf.buf);
            //printk("UART_RX_BUF_RELEASED\n");
		break;
		case UART_RX_DISABLED:
		    printk("UART_RX_DISABLED\n");
		break;
		case UART_RX_STOPPED:
		    printk("UART_RX_STOPPED\n");
		break;
	}
}

I think i'm on the right way,

do you have advice about that ?

Best regards,

Lam

[Kazi Afroza Sultana]

Hello,

We think the problem lies where it is starting and stopping the UART. Can you check this (+) How can I enable and disable UART devices at run time on nRF9160? - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com) case? You may need to check the RXTO event. 

Thanks.

BR

Kazi

[Lamdev]

Hello,

Thanks for your help,

I found a solution that was the following, if this can help someone.

void button_pressed(const struct device *dev, struct gpio_callback *cb,
		    uint32_t pins)
{
	int ret;

	printk("Button pressed\r\n");

	ret = gpio_pin_interrupt_configure(button.port,button.pin,GPIO_INT_DISABLE);		//GPIO_INT_EDGE_BOTH
	if (ret != 0) {
		printk("Error disable INT\r\n");
		return;
	}
	
	//restart_uart();
	k_work_submit(&button_action_work);
	//flag_interrupt = 1;
}

//gpio for UART interrupt definition
void configure_int_rx(void){
	int ret;

	printk("configure interrupt\r\n");

	if (!device_is_ready(button.port)) {
		printk("Error config INT 1\r\n");
		return;
	}
	
	ret = gpio_pin_configure(button.port,button.pin,GPIO_INPUT);
	if (ret != 0) {
		printk("Error config INT 2\r\n");
		return;
	}

	ret = gpio_pin_interrupt_configure(button.port,button.pin,GPIO_INT_EDGE_TO_ACTIVE);		//GPIO_INT_EDGE_BOTH
	if (ret != 0) {
		printk("Error config INT 3\r\n");
		return;
	}

	gpio_init_callback(&button_cb_data, button_pressed, BIT(button.pin));

	ret = gpio_add_callback(button.port, &button_cb_data);
	if (ret != 0) {
		printk("Error config INT 4\r\n");
		return;
	}

	printk("Config INT OK\r\n");
}

void timer_disable_uart_work_fn(struct k_work *work)
{
	disable_uart();
    configure_int_rx();
}

void process_work_timer_uart_disable(void){
	//scehdule a time to disable uart
    //cancel last schedule
    if(k_work_delayable_busy_get(&timer_disable_uart_work) != 0 ){
        k_work_cancel_delayable(&timer_disable_uart_work);
		while(k_work_delayable_busy_get(&timer_disable_uart_work) != 0 );	//wait until cancelation finnish
    }
    //enable new schedule
    k_work_schedule(&timer_disable_uart_work, K_SECONDS(WAIT_UART_DISABLE));
}

/* other code line to use to work */
#define SWIN3_NODE	DT_ALIAS(swin3)
#if !DT_NODE_HAS_STATUS(SWIN3_NODE, okay)
#error "Unsupported board: SWIN3 devicetree alias is not defined"
#endif


static const struct gpio_dt_spec button = GPIO_DT_SPEC_GET_OR(SWIN3_NODE, gpios,0); 
static struct gpio_callback button_cb_data;

K_WORK_DEFINE(button_action_work, button_action_work_handler);
void button_action_work_handler(struct k_work *work) {
    //do_something_because_a_button_was_pressed();
	restart_uart();
}

static struct k_work_delayable timer_disable_uart_work;

k_work_init_delayable(&timer_disable_uart_work,timer_disable_uart_work_fn);

[Kazi Afroza Sultana]

Thanks for sharing the code. I am glad that you have fixed the issue.