in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

Einar Thorsrud — Tue, 25 May 2021 08:44:06 GMT

Hi,

Please make a separate thread for this question, as it is unrelated to your original question in this thread.

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Mon, 24 May 2021 02:53:16 GMT

thank you

in my project, I use SPI inerface (4 pin(pin must can been changed)) communicated with a 4G TF card, this card must mount in Zephyr filesystem , in connect SDK\ v1.5.0\zephyr\samples\subsys\fs\fat_fs , this sample can get some advice . I can use SPI read and write TF card how can i mount this card in zephyr filesystem and use file API fuctinon , would I should re-edit some read/write API fountion of Zephyr filesystem?

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

Einar Thorsrud — Wed, 12 May 2021 07:32:54 GMT

Hi,

Good to hear it works. yes, the code you deleted is only needed to initiate the data length (DLE) update procedure from the nRF. As long as you have done the correct adjustments in prj.conf files it will be supported by the BLE stack, so the peer can initiate DLE.

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Wed, 12 May 2021 06:39:04 GMT

Einar Thorsrud:

thank you very much!!!

today i delete code below:

struct bt_conn_le_data_len_param data_len_param;
data_len_param.tx_max_len = 80; // byte
data_len_param.tx_max_time = 3750; // us
err = bt_conn_le_data_len_update(current_conn, &data_len_param);

also can increase ble send data number .maybe only change two or one prj.conf , using app that connected with nrf5340dk through ble .in app there is a configuration of MTU on menu or dialoge

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Wed, 12 May 2021 01:53:26 GMT

I can know some skill ,the app connected with nrf5340dk through BLE must cooperate .,in the imagine top -right ,there are 3 dots ranged in vertical ，touch these 3 dots can pop an input editor dialoge , you can change MTU from 23 to 517 , input 251 (the largest size of ble can send a pack) can change MTU to maxium value,touch OK button ,then ble MTU of the connected nrf5340dk also update with this value(this situation will come into truth with the correct code in nrf5340dk)

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Tue, 11 May 2021 12:31:25 GMT

when I send data from sscom's send editor more than 20 bytes ,the debugging segger embedded studio pop information below:

[00:01:23.371,826] bt_att: No ATT channel for MTU 43
[00:01:23.371,856] bt_gatt: No buffer available to send notification
[00:01:23.371,856] peripheral_uart: Failed to send data over BLE connection
[00:01:37.619,506] bt_att: No ATT channel for MTU 48
[00:01:37.619,537] bt_gatt: No buffer available to send notification
[00:01:37.619,537] peripheral_uart: Failed to send data over BLE connection
[00:01:37.910,400] bt_att: No ATT channel for MTU 48
[00:01:37.910,400] bt_gatt: No buffer available to send notification
[00:01:37.910,430] peripheral_uart: Failed to send data over BLE connection
[00:01:38.141,235] bt_att: No ATT channel for MTU 48
[00:01:38.141,235] bt_gatt: No buffer available to send notification
[00:01:38.141,265] peripheral_uart: Failed to send data over BLE connection
[00:01:38.332,031] bt_att: No ATT channel for MTU 48
[00:01:38.332,061] bt_gatt: No buffer available to send notification
[00:01:38.332,061] peripheral_uart: Failed to send data over BLE connection
[00:01:38.532,836] bt_att: No ATT channel for MTU 48
[00:01:38.532,867] bt_gatt: No buffer available to send notification
[00:01:38.532,867] peripheral_uart: Failed to send data over BLE connection
[00:01:38.723,632] bt_att: No ATT channel for MTU 48
[00:01:38.723,632] bt_gatt: No buffer available to send notification
[00:01:38.723,663] peripheral_uart: Failed to send data over BLE connection
[00:01:38.994,506] bt_att: No ATT channel for MTU 48
[00:01:38.994,506] bt_gatt: No buffer available to send notification
[00:01:38.994,537] peripheral_uart: Failed to send data over BLE connection
[00:01:39.195,312] bt_att: No ATT channel for MTU 48
[00:01:39.195,343] bt_gatt: No buffer available to send notification
[00:01:39.195,343] peripheral_uart: Failed to send data over BLE connection
[00:01:39.376,098] bt_att: No ATT channel for MTU 48
[00:01:39.376,129] bperipheral_uart: Failed to send data over BLE connection

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Tue, 11 May 2021 12:23:26 GMT

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Tue, 11 May 2021 12:14:50 GMT

when debug go there are informatipn below:

[00:00:00.028,442] bt_hci_core: ECC HCI commands not available

[00:00:00.028,472] bt_hci_core: No ID address. App must call settings_load()

[00:00:00.028,472] peripheral_uart: Bluetooth initialized

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Tue, 11 May 2021 12:04:02 GMT

thank Einar Thorsrud!

I changed example as you had told to me . i build solution.use git_cmd,erase cpu net,in main.c change #define UART_BUF_SIZE 20 into #define UART_BUF_SIZE 70 ,in uart_cb()

case UART_RX_RDY:

......
if (buf->len == 40) {
......
}

build/debug ,go ,from ble of board ,the largest bytes is still 20 that can be send to APP.

do zephyr\samples\bluetooth\hci_rpmsg\prj.conf have no effect to cpu_net core of example peripheral_uart ?

i program the cpu_net core of example peripheral_uart with \nrf\samples\bluetooth\peripheral_uart\build_nrf5340dk_nrf5340_cpuappns\hci_rpmsg\zephyr\ merged_CPUNET.hex .

program can run well and connect with app and not reset.

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

Einar Thorsrud — Tue, 11 May 2021 10:01:10 GMT

Hi,

You have some issues in your code, and I suspect you did not configure the stack on the network core. The following quick and dirty changes to the peripheral_uart sample does what you want and I tested to verify that the data length is updated to 80 upon establishing the connection:

devzone.nordicsemi.com/.../6710.main.c.diff

devzone.nordicsemi.com/.../peripheral_5F00_uart_5F00_prj.conf.diff

Here is update for the network core by changing zephyr\samples\bluetooth\hci_rpmsg\prj.conf (note that I also reduced CONFIG_BT_MAX_CONN in order to make this fit in RAM):

devzone.nordicsemi.com/.../hci_5F00_rpmsg_5F00_prj.conf.diff

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Tue, 11 May 2021 09:04:17 GMT

[quote userid="103127" url="~/f/nordic-q-a/74604/in-connect-sdk-v1-5-0-nrf-samples-bluetooth-peripheral_uart-data-number-is-limited-20-bytes-more-than-20bytes-ble-will-part-data-in-two-or-more-packs-to-send-or-receive/309146#309146"]on[/quote]

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Tue, 11 May 2021 08:41:16 GMT

Einar Thorsrud

thank you

I konw you ar very busy ,could you take some time to test peripheral_uart in NCS v1.5.0 with a nrf5340_dk kit ,increase the number of ble that could send to a connected APP in a phone . in this nordic community ,few people know the answer。could you spend some time to reprogram the peripheral_uart example . could you accept my mailbox and mail with me?

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Tue, 11 May 2021 07:58:27 GMT

in prj.conf ,I add below:

CONFIG_BT_USER_DATA_LEN_UPDATE=y
CONFIG_BT_CTLR_TX_BUFFER_SIZE=251
CONFIG_BT_CTLR_DATA_LENGTH_MAX=251
CONFIG_BT_L2CAP_TX_MTU=247
CONFIG_BT_L2CAP_RX_MTU=247
CONFIG_BT_MAX_CONN=2

in main.c , bt_callback function connect ,I add below:

static void connected(struct bt_conn *conn, uint8_t err)
{
......

current_conn = bt_conn_ref(conn);
err2 = bt_conn_le_data_len_update(current_conn, 80);
if (err2)
printk( "LE data length update failed: %d", err2);

......
}

all other not changed,but build\debug\go ,the board always reset,can not run,,ble app cannot connect board ,is there other place need to be modified in program,

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

Einar Thorsrud — Tue, 11 May 2021 07:11:37 GMT

Hi,

You can call bt_conn_le_data_len_update() after a connection has been established. As you are using the nrf/samples/bluetooth/peripheral_uart sample there is allready a callback function called connected(). Here you get a handle to the current connection - current_conn. Once you have that you can call bt_conn_le_data_len_update(). Please refer to nrf\samples\bluetooth\throughput\src\main.c for an example.

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Mon, 10 May 2021 14:19:33 GMT

thank Einar Thorsrud

I do not know where to insert the function bt_conn_le_data_len_update() ? insert this function in bt_enable() of main.c or in a place of function void main(void) of main.c or other place of flle belonged to this project ? it is initiated by the peer , peer is a app in phone that will connect NRF5340_DK through ble?

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

Einar Thorsrud — Mon, 10 May 2021 12:43:18 GMT

Hi,

Do you start the data length update procedure by calling bt_conn_le_data_len_update()? Or is it initiated by the peer? If not, then this is expected.

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Mon, 10 May 2021 11:56:41 GMT

example peripheral_uart in nrf connect SDK v1.5.0 , i use nrf5340_DK test this example with a bluetooth APP in a phone ,the largest bytes of nrf5340_dk kit can send to app is 20 a time, how can i increase data number ?

in prj.conf, i add below:

CONFIG_BT_USER_DATA_LEN_UPDATE=y
CONFIG_BT_CTLR_TX_BUFFER_SIZE=251
CONFIG_BT_CTLR_DATA_LENGTH_MAX=251

in att_internal.h , change # define BT_ATT_DEFAULT_LE_MTU 23 into # define BT_ATT_DEFAULT_LE_MTU 43

in gap.h , change # define BT_GAP_DATA_LEN_DEFAULT 0x1b into # define BT_GAP_DATA_LEN_DEFAULT 0x2e

in main.c , chang function uart_cb( ) {.......

case UART_RX_RDY:
......;
if (buf->len == 30) {...... }

}

i only change above ，anther have the same as original example .

build/debug go ,have no result ,the largest number of ble of nrf5340-dk can send to app of phone is still 20 bytes ,not 30 bytes 。is there any other code to be modified in this example? someone said that nrf connect SDK v1.5.0 need to be updated to ble5.0 version , ble4.0 version can not send more than 20 bytes through ble a time

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

Einar Thorsrud — Mon, 10 May 2021 10:21:04 GMT

Hi,

[quote user="zhouhaifang"]you had said these two threads have no effect to program[/quote]

No, that is not what I meant. What I mean is that this is part of the implementation of the BLE stack and not something you are mint to modify.

[quote user="zhouhaifang"]can these two threads be deleted?[/quote]

No.

[quote user="zhouhaifang"]what's difference bluetooth host layer thread and APP thread?[/quote]

There is no fundamental difference, a thread is a thread. But you if you are using the Bluetooth stack, then you do not normally need to think much about how it is implemented. So in a nutshell tx_thread_data() and ble_write_thread_id() as internal details you do not normally need to think about.

[quote user="zhouhaifang"]in file main.c ,the code K_THREAD_DEFINE(ble_write_thread_id, STACKSIZE, ble_write_thread, NULL, NULL,
NULL, PRIORITY, 0, 0); creat ble_write_thread ,but I search whole entire solution ,the word "ble_write_thread_id " has referrenced in only one place ,how the program know word ble_write_thread_id ?[/quote]

All threads need a name/ID as that is a requirement of the Zephyr thread API. However, in this case this is a thread that is crated once and runs forever, so there is no need to refer to it from anywhere else. Therefor, you will not see ble_write_thread_id used anywhere.

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Sat, 08 May 2021 01:31:54 GMT

in example peripheral_uart of NRF Connect SDK1.5.0 , in main(),the bt_enble() creats two bluetooth threads,a TX thread and a RX thread,you had said these two threads have no effect to program,can these two threads be deleted?what's difference bluetooth host layer thread and APP thread? in file main.c ,the code K_THREAD_DEFINE(ble_write_thread_id, STACKSIZE, ble_write_thread, NULL, NULL,
NULL, PRIORITY, 0, 0); creat ble_write_thread ,but I search whole entire solution ,the word "ble_write_thread_id " has referrenced in only one place ,how the program know word ble_write_thread_id ?

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

Einar Thorsrud — Fri, 07 May 2021 09:48:20 GMT

Hi,

The first code snippet is from the implementation of bt_enable(), which is in the host layer of the BT stack. So these are not something you normally need to think of at all as it is internal to the stack.

The ble_write_thread() on the other hand is a thread implemented in the sample app that uses the BT API, and in an eternal loop pops incoming UART data from a queue and sends it over BLE NUS.

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Fri, 07 May 2021 02:05:51 GMT

in example peripheral_uart ,in function main() use err = bt_enable(NULL) creat two thread:

/* TX thread */
k_thread_create(&tx_thread_data, tx_thread_stack,
K_KERNEL_STACK_SIZEOF(tx_thread_stack),
hci_tx_thread, NULL, NULL, NULL,
K_PRIO_COOP(CONFIG_BT_HCI_TX_PRIO),
0, K_NO_WAIT);

/* RX thread */
k_thread_create(&rx_thread_data, rx_thread_stack,
K_KERNEL_STACK_SIZEOF(rx_thread_stack),
(k_thread_entry_t)hci_rx_thread, NULL, NULL, NULL,
K_PRIO_COOP(CONFIG_BT_RX_PRIO),
0, K_NO_WAIT);

but in the file main.c , example use below code to creat anther bluetooth TX thread and anther blue RX callback function :

void ble_write_thread(void)
{
/* Don't go any further until BLE is initialized */
k_sem_take(&ble_init_ok, K_FOREVER);

for (;;) {
/* Wait indefinitely for data to be sent over bluetooth */

struct uart_data_t *buf = k_fifo_get(&fifo_uart_rx_data,
K_FOREVER);

if (bt_nus_send(NULL, buf->data, buf->len)) {
LOG_WRN("Failed to send data over BLE connection");
}

k_free(buf);

}
}

K_THREAD_DEFINE(ble_write_thread_id, STACKSIZE, ble_write_thread, NULL, NULL,
NULL, PRIORITY, 0, 0);

static void bt_receive_cb(struct bt_conn *conn, const uint8_t *const data,
uint16_t len)
{
int err;
char addr[BT_ADDR_LE_STR_LEN] = {0};

bt_addr_le_to_str(bt_conn_get_dst(conn), addr, ARRAY_SIZE(addr));

LOG_INF("Received data from: %s", log_strdup(addr));

for (uint16_t pos = 0; pos != len;) {
struct uart_data_t *tx = k_malloc(sizeof(*tx));

if (!tx) {
LOG_WRN("Not able to allocate UART send data buffer");
printk("Not able to allocate UART send data buffer");
return;
}

/* Keep the last byte of TX buffer for potential LF char. */
size_t tx_data_size = sizeof(tx->data) - 1;

if ((len - pos) > tx_data_size) {
tx->len = tx_data_size;
} else {
tx->len = (len - pos);
}

memcpy(tx->data, &data[pos], tx->len);

pos += tx->len;

/* Append the LF character when the CR character triggered
* transmission from the peer.
*/

if ((pos == len) && (data[len - 1] == '\r')) {
tx->data[tx->len] = '\n';
tx->len++;
}

err = uart_tx(uart, tx->data, tx->len, SYS_FOREVER_MS);
if (err) {
k_fifo_put(&fifo_uart_tx_data, tx);
}

}
}

WHAT'S RELATIONSHIP BETWEEN thread/function created by FUNCTION bt_enable() and file main.c ?

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

Einar Thorsrud — Thu, 06 May 2021 10:31:11 GMT

The example is intended for two DKs yes, but you can refer to the example to see how you can support data length update (DLE). You can see relevant configurations in the prj.conf. Specifically you should add:

CONFIG_BT_USER_DATA_LEN_UPDATE=y
CONFIG_BT_CTLR_TX_BUFFER_SIZE=251
CONFIG_BT_CTLR_DATA_LENGTH_MAX=251

If you want to start the DLE procedure from the nRF you call bt_conn_le_data_len_update().

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

zhouhaifang — Thu, 06 May 2021 07:01:36 GMT

thank Einar Thorsrud ,in example throughput need "

Testing

After programming the sample to both kits, test it by performing the following steps:

",now i have only one nrf5340dk board ,the test is a bluetooth APP in a phone with nrf5340dk , i cannot flash APP ,the APP GAP payload is more than 200 BYTES ,how can i send more than 20 bytes in a bluetooth packet to APP in example peripheral_uart

RE: in \connect SDK\v1.5.0\nrf\samples\bluetooth\peripheral_uart,data number is limited 20 bytes, more than 20bytes BLE will part data in two or more packs to send or receive

Einar Thorsrud — Fri, 30 Apr 2021 12:45:29 GMT

Hi,

20 byte is the maximum payload you get per packet without using DLE (GAP payload is 23 byte, and 3 byte GATT header leaving 20 byte data). To send longer packets you need to use data length extension. To support that you need to set CONFIG_BT_USER_DATA_LEN_UPDATE=y in your prj.conf and use bt_conn_le_data_len_update() to initiate the DLE procedure. You can see an example of this sin the Bluetooth: Throughput sample.