data size in PAwR slot response

[Yanis]

Hello,

I am developping an application based on PAwR (Periodic Advertsing with response) in coded PHY (S8) extended advertising on SDK 2.7.0.

costum chip nrf52840 (on Fanstel BT840F)

My code is based on the Nordic demo :

8562.PAwR_Demo.zip 

Periodic Advertising with Responses (PAwR): A practical guide - Software - nRF Connect SDK guides - Nordic DevZone

I am not able to send a payload greater than 55 bytes in the response slot,

I am getting an error with the function responsible of sending data (in the recv_cb) :

        err = bt_le_per_adv_set_response_data(current_sync, &rsp_params, &rsp_buf);

        

  bt_hci_core: opcode 0x2083 status 0x45

  beacon: recv_cb: Failed to send response (err -5)

The buffer was initialised as the following :

NET_BUF_SIMPLE_DEFINE_STATIC(rsp_buf, 247);

static uint8_t buffer[60] = {0x00};

but when the buffer is set to buffer[55], it works fine.

Here is the configs related to the PAwR :

CONFIG_BT=y
CONFIG_BT_BROADCASTER=y
CONFIG_BT_EXT_ADV=y
CONFIG_BT_PER_ADV=y
CONFIG_BT_DEVICE_NAME="PAwR adv sample"

CONFIG_BT_MAX_CONN=1
CONFIG_BT_CENTRAL=y
CONFIG_BT_PER_ADV_SYNC_TRANSFER_SENDER=y

# This example requires more workqueue stack
CONFIG_MAIN_STACK_SIZE=2304
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048
CONFIG_BT_RX_STACK_SIZE=2048


CONFIG_BT_CTLR_ADV_DATA_LEN_MAX=191

Here are the PAwR timing parameters:

static const struct bt_le_per_adv_param per_adv_params = {
	.interval_min = 4800, //4800 6s,
	.interval_max = 4800, //4800 6s,  
	.options = 0,
	.num_subevents = 20,
	.subevent_interval = 240, //240 = 300ms
	.response_slot_delay = 5, // 6.25 ms = 5*1.25
	.response_slot_spacing = 150, //150= 18.75ms
	.num_response_slots = 15,
};

We can read in the specifications that the size of the payload can be up to 255 bytes in extended advertising mode (and even more via packet chaining.

and the kconfig show the following :

config BT_CTLR_ADV_DATA_LEN_MAX

    int "Maximum Advertising Data Length"

    depends on BT_BROADCASTER

    range 31 191 if BT_LL_SW_SPLIT && !BT_CTLR_ADV_DATA_CHAIN

    range 31 1650

    help

      Maximum Extended Advertising Data Length.

 

Thanks in advance for your assistance,

Regards,

Yanis

[longrain]

take a look at

CONFIG_BT_CTLR_SDC_PERIODIC_ADV_RSP_TX_MAX_DATA_SIZE

CONFIG_BT_PER_ADV_SYNC_BUF_SIZE

[Yanis]

When I set the following, it does not solve the problem :

CONFIG_BT_PER_ADV=y

CONFIG_BT_PER_ADV_RSP=y

CONFIG_BT_CTLR_SDC_PAWR_ADV=y

CONFIG_BT_CTLR_SDC_PERIODIC_ADV_RSP_TX_MAX_DATA_SIZE=245

CONFIG_BT_PER_ADV_SYNC_BUF_SIZE=245

still getting the error :

<wrn> bt_hci_core: opcode 0x2083 status 0x45\033[0m
<dbg> beacon: recv_cb: Failed to send response (err -5)

[longrain]

Sorry,I misunderstand your error info.

I have test :it is OK to send long packet in NCS 2.9 and NCS 3.0,coded PHY maybe need more time.

I upload a test sample test in NCS 3.0.x with 54L,send over 200 bytes both direction.

Check if it can help

 pawr_test.rar

[Yanis]

I am not sure if I understand, are you saying that coded PHY could be the limitation ?

In the code you have sent me, I don't think you are sending 200 bytes when you set :

        net_buf_simple_add_mem(&rsp_buf, buf->data, buf->len);

it seems that you are returning the counter you received which is 1 or 2 bytes.

In my case I have :

        net_buf_simple_add_mem(&rsp_buf, buffer, ARRAY_SIZE(buffer));

where "buffer" is declared as :

static uint8_t buffer[60] = {0x00};

 

[Yanis]

When I put a buffer > 55 bytes I also get this error on the advertiser side

ASSERTION FAIL [z_spin_lock_valid(l)] @ WEST_TOPDIR/zephyr/include/zephyr/spinlock.h:136<CR><LF>
<HT> Invalid spinlock 0x20000b80<CR><LF>

And the sync is lost.