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]

Hello,

I'm able to disable my uart with this part of code : 

uint8_t disable_uart(void){

    //Disable uart0 which use to exchange message between modem and an external device
    NRF_UARTE0_NS->TASKS_STOPTX = 1;
    NRF_UARTE0_NS->TASKS_STOPRX = 1;
    NRF_UARTE0_NS->ENABLE = 0;

    //configure RX pin int o input gpio
    const struct device * gpio_dev = DEVICE_DT_GET(DT_NODELABEL(gpio0));
    gpio_pin_configure(gpio_dev,6, GPIO_INPUT);
   
}

And i obtain an power consumption arround 6uA.

Now i'm trying to convert my RX gpio into an interrupt GPIO but without success.

I have try this after checking information in the sample button in SDK

#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, gpios,{0}); 
static struct gpio_callback button_cb_data;

void button_pressed(const struct device *dev, struct gpio_callback *cb,
		    uint32_t pins)
{
	printk("Button pressed\r\n");
}

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

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

	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);

}

The resultat that i obtain is a reboot of my board every time the code start to execute "configure_int_rx" function.

Update below

thanks for your help,

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