Stop scanning and start advertising

[Kevin_Liu]

Hi,

I am developing application on  NRF52840 with Zepyr  2.1.2 SDK, and I found two problems when using the example scan_adv, as follows:

• Executing bt_le_scan_start in the main function can receive data smoothly, but using function scan_start() can not receive data, the same problem also occurs in bt_le_adv_start().
• Executing bt_le_scan_stop() still cannot stop scanning.

My codeis as below:

#include <zephyr/types.h>
#include <stddef.h>
#include <zephyr/sys/printk.h>
#include <zephyr/sys/util.h>
#include <zephyr/toolchain.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/hci.h>
#include <device.h>
#include <devicetree.h>
#include <drivers/gpio.h>

struct bt_le_scan_param scan_param = {
		.type       = BT_HCI_LE_SCAN_PASSIVE,
		.options    = BT_LE_SCAN_OPT_NONE,
		.interval   = BT_GAP_SCAN_FAST_INTERVAL,
		.window     = 0x0010,
	};
const struct device *dev;
int state = 1, adv_state;
int8_t rssi_data [8][8] = {0};
static uint8_t mfg_data[] = { 0xff, 0xff, 0x01 };
static const struct bt_data ad[] = {
	BT_DATA(BT_DATA_MANUFACTURER_DATA, mfg_data, 3),
	BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME,DEVICE_NAME_LEN)
};


void scan_cb(const bt_addr_le_t *addr, int8_t rssi, uint8_t adv_type,
	   struct net_buf_simple *buf)
{...}

void adv_start(uint8_t mfg){
	mfg_data[2] = mfg;
	int err = bt_le_adv_start(BT_LE_ADV_NCONN, ad, ARRAY_SIZE(ad), NULL, 0);
	if (err) {
		printk("Advertising failed to start (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
}

static void adv_stop(){
	int err = bt_le_adv_stop();
	if (err) {
		printk("Advertising failed to stop (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
}
void scan_start(){
	int err = bt_le_scan_start(&scan_param, scan_cb);
		if (err) {
			printk("Starting scanning failed (err %d)\n", err);
			return;
		}
		k_sleep(K_MSEC(400));
}

static void scan_stop(){
	int err = bt_le_scan_stop();
	if (err) {
		printk("Stop scanning failed (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
}


void main(void)
{
	int err = bt_enable(NULL);
	if (err) {
		printk("Bluetooth init failed (err %d)\n", err);
		return;
	}
	printk("Bluetooth initialized\n");
	scan_start();

	/*  if not use scan_start()
	*********************************************************
	int err = bt_le_scan_start(&scan_param, scan_cb);
	if (err) {
		printk("Starting scanning failed (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
	********************************************************
	*/

	k_sleep(K_MSEC(800));
	//scan_stop();
	int err = bt_le_adv_stop();
	if (err) {
		printk("Advertising failed to stop (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
	while(1);
}

Thanks.

[Vidar Berg]

Hi,

I see from your code snippet that you call bt_le_adv_stop() at the end. Is that a typo? If you want to stop scanning, you will have to use bt_le_scan_stop()/scan_stop().

Best regards,

Vidar

[Kevin_Liu]

Hi,

Thank you for your reply, I changed it to bt_le_scan_stop but still have the same problem, is there any way to stop scanning?

In addition, using function scan_start() still cannot receive data.

my program is as follows:

#include <zephyr/types.h>
#include <stddef.h>
#include <zephyr/sys/printk.h>
#include <zephyr/sys/util.h>
#include <zephyr/toolchain.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/hci.h>
#include <device.h>
#include <devicetree.h>
#include <drivers/gpio.h>

struct bt_le_scan_param scan_param = {
		.type       = BT_HCI_LE_SCAN_PASSIVE,
		.options    = BT_LE_SCAN_OPT_NONE,
		.interval   = BT_GAP_SCAN_FAST_INTERVAL,
		.window     = 0x0010,
	};
const struct device *dev;
int state = 1, adv_state;
int8_t rssi_data [8][8] = {0};
static uint8_t mfg_data[] = { 0xff, 0xff, 0x01 };
static const struct bt_data ad[] = {
	BT_DATA(BT_DATA_MANUFACTURER_DATA, mfg_data, 3),
	BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME,DEVICE_NAME_LEN)
};


void scan_cb(const bt_addr_le_t *addr, int8_t rssi, uint8_t adv_type,
	   struct net_buf_simple *buf)
{...}

void adv_start(uint8_t mfg){
	mfg_data[2] = mfg;
	int err = bt_le_adv_start(BT_LE_ADV_NCONN, ad, ARRAY_SIZE(ad), NULL, 0);
	if (err) {
		printk("Advertising failed to start (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
}

static void adv_stop(){
	int err = bt_le_adv_stop();
	if (err) {
		printk("Advertising failed to stop (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
}
void scan_start(){
	int err = bt_le_scan_start(&scan_param, scan_cb);
		if (err) {
			printk("Starting scanning failed (err %d)\n", err);
			return;
		}
		k_sleep(K_MSEC(400));
}

static void scan_stop(){
	int err = bt_le_scan_stop();
	if (err) {
		printk("Stop scanning failed (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
}


void main(void)
{
	int err = bt_enable(NULL);
	if (err) {
		printk("Bluetooth init failed (err %d)\n", err);
		return;
	}
	printk("Bluetooth initialized\n");
	scan_start();

	/*  if not use scan_start()
	*********************************************************
	int err = bt_le_scan_start(&scan_param, scan_cb);
	if (err) {
		printk("Starting scanning failed (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
	********************************************************
	*/

	k_sleep(K_MSEC(800));
	//scan_stop();
	int err = bt_le_scan_stop();
	if (err) {
		printk("Stop scanning failed (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
	while(1);
}

[Vidar Berg]

Kevin_Liu said:

I changed it to bt_le_scan_stop but still have the same problem, is there any way to stop scanning?

Please explain how you determine that it does not stop. Is it because bt_le_scan_stop() returns with an error?

Kevin_Liu said:

In addition, using function scan_start() still cannot receive data.

Does scan_start() report any errors?

Kevin_Liu said:

my program is as follows:

Can you post the updated code please? The snippet you posted will not build because the 'err' variable being defined twice in main() 

[Kevin_Liu]

...

I use J-Link RTT Viewer V7.58b as a debugging tool. After the bt_le_scan_stop() function is executed, the scan_cb() function continues to work without error

Vidar Berg said:

Does scan_start() report any errors?

No error occurs, but scan_cb() function does not send any message

Vidar Berg said:

Can you post the updated code please? The snippet you posted will not build because the 'err' variable being defined twice in main()

#include <zephyr/types.h>
#include <stddef.h>
#include <zephyr/sys/printk.h>
#include <zephyr/sys/util.h>
#include <zephyr/toolchain.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/hci.h>
#include <device.h>
#include <devicetree.h>
#include <drivers/gpio.h>

struct bt_le_scan_param scan_param = {
		.type       = BT_HCI_LE_SCAN_PASSIVE,
		.options    = BT_LE_SCAN_OPT_NONE,
		.interval   = BT_GAP_SCAN_FAST_INTERVAL,
		.window     = 0x0010,
	};
const struct device *dev;
int state = 1, adv_state;
int8_t rssi_data [8][8] = {0};
static uint8_t mfg_data[] = { 0xff, 0xff, 0x01 };
static const struct bt_data ad[] = {
	BT_DATA(BT_DATA_MANUFACTURER_DATA, mfg_data, 3),
	BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME,DEVICE_NAME_LEN)
};


void scan_cb(const bt_addr_le_t *addr, int8_t rssi, uint8_t adv_type,
	   struct net_buf_simple *buf)
{
	printk("scan_cb start\n");
	char data_str[129];
	bin2hex(buf->data, buf->len, data_str, sizeof(data_str));
	printk("data_str is : %s\n", data_str);
}

void adv_start(uint8_t mfg){
	mfg_data[2] = mfg;
	int err = bt_le_adv_start(BT_LE_ADV_NCONN, ad, ARRAY_SIZE(ad), NULL, 0);
	if (err) {
		printk("Advertising failed to start (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
}

static void adv_stop(){
	int err = bt_le_adv_stop();
	if (err) {
		printk("Advertising failed to stop (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
}
void scan_start(){
	int err = bt_le_scan_start(&scan_param, scan_cb);
		if (err) {
			printk("Starting scanning failed (err %d)\n", err);
			return;
		}
		k_sleep(K_MSEC(400));
}

static void scan_stop(){
	int err = bt_le_scan_stop();
	if (err) {
		printk("Stop scanning failed (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
}


void main(void)
{
	int err = bt_enable(NULL);
	if (err) {
		printk("Bluetooth init failed (err %d)\n", err);
		return;
	}
	printk("Bluetooth initialized\n");
	scan_start();

	/*  if not use scan_start()
	*********************************************************
	err = bt_le_scan_start(&scan_param, scan_cb);
	if (err) {
		printk("Starting scanning failed (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
	********************************************************
	*/

	k_sleep(K_MSEC(800));
	//scan_stop();
	err = bt_le_scan_stop();
	if (err) {
		printk("Stop scanning failed (err %d)\n", err);
		return;
	}
	k_sleep(K_MSEC(400));
	while(1);
}

[Vidar Berg]

This is what when I run the code you posted now:

So, it appears to be working as expected?

Here is the hex file I built with your code if you want to try the same on your board:

2248.zephyr.hex