RE: Sending consecutive 7 notification on ble characteristic issue

VboZ — Thu, 29 Oct 2020 05:50:33 GMT

I have the same problem. It looks like a limitation on the mobile phone, Whether I use nRF Connect on iOS or Android. The same situation is that the limit of continuous notification is 4. If you want to receive the fifth notification, you must add a delay more than 200ms between the fourth and fifth notifications sent on the peripheral.

RE: Sending consecutive 7 notification on ble characteristic issue

Jared — Tue, 12 May 2020 12:39:45 GMT

Hello,

I'm very sorry for the late reply. Are you still having problems with this?

regards

Jared

RE: Sending consecutive 7 notification on ble characteristic issue

adnan arshad — Wed, 25 Mar 2020 16:18:33 GMT

Yes i am using nRF Connect on mobile side.

I have modified the ble_app_blinky example in sdk 16. on button write characteristic i send consecutive notification on a notify characteristic using the following function

uint32_t ble_on_tx_frame(uint16_t conn_handle, ble_lbs_t * p_lbs, uint8_t* p_tx_data)
{
ble_gatts_hvx_params_t params;
uint16_t len = 16;

memset(&params, 0, sizeof(params));
params.type = BLE_GATT_HVX_NOTIFICATION;
params.handle = p_lbs->notify_char_handles.value_handle;
params.p_data = p_tx_data;
params.p_len = &len;

return sd_ble_gatts_hvx(conn_handle, &params);
}

// The following function is called in button write handle event of the button characteristic

void GetEncrypted_text(uint8_t opcode)
{
uint32_t err_code;
uint8_t tx_packet_array[16];
if(opcode == 0x03)
{
(void) memset(g_tx_command,0,200);

static char m_plain_text[] =
{
"Example string to demonstrate AES CBC mode with padding. This text has 85 characters."
};
uint16_t len_out = sizeof(g_tx_command);
uint16_t len_in = sizeof(m_plain_text);
encrypt_cbc(&m_plain_text[0], len_in, &g_tx_command[0],len_out);

tx_packet_array[0] = 1<<7;
tx_packet_array[0] |= opcode;
tx_packet_array[1] |= 0x07; // no of frames
tx_packet_array[2] |= 0x55; // crc low
tx_packet_array[3] |= 0xA5; // crc high

//(void) memset(&tx_packet_array[4],1,12); // First Chunk

(void) memcpy(&tx_packet_array[4],&g_tx_command,12); // First Chunk
ble_on_tx_frame(m_conn_handle, &m_lbs, &tx_packet_array[0]);

tx_packet_array[0] = 0xFF; // Second Chunk
(void) memcpy(&tx_packet_array[1],&g_tx_command[12],15);

err_code = ble_on_tx_frame(m_conn_handle, &m_lbs, &tx_packet_array[0]);
nrf_delay_ms(5);

tx_packet_array[0] = 0xFF; // Third Chunk
(void) memcpy(&tx_packet_array[1],&g_tx_command[27],15);

ble_on_tx_frame(m_conn_handle, &m_lbs, &tx_packet_array[0]);
nrf_delay_ms(5);

tx_packet_array[0] = 0xFF; // Fourth Chunk
(void) memcpy(&tx_packet_array[1],&g_tx_command[42],15);

ble_on_tx_frame(m_conn_handle, &m_lbs, &tx_packet_array[0]);
nrf_delay_ms(25);

tx_packet_array[0] = 0xFF; // Fifth Chunk
(void) memcpy(&tx_packet_array[1],&g_tx_command[57],15);

ble_on_tx_frame(m_conn_handle, &m_lbs, &tx_packet_array[0]);
nrf_delay_ms(5);

tx_packet_array[0] = 0xFF; // Sixth Chunk
(void) memcpy(&tx_packet_array[1],&g_tx_command[72],15);

ble_on_tx_frame(m_conn_handle, &m_lbs, &tx_packet_array[0]);
nrf_delay_ms(5);

tx_packet_array[0] = 0xFE; // Seventh Chunk
(void) memcpy(&tx_packet_array[1],&g_tx_command[87],9);

(void) memset(&tx_packet_array[10],0,6);
ble_on_tx_frame(m_conn_handle, &m_lbs, &tx_packet_array[0]);

}

Only first three or some time four notifications are received in nrf Connect side.

RE: Sending consecutive 7 notification on ble characteristic issue

Jared — Wed, 25 Mar 2020 14:41:27 GMT

Hi,

What application are you using on the android side, is it nRF Connect?
Is the BLE_GATTS_EVT_HVN_TX_COMPLETE event generated when the notifications are sent?
Could you share your project?

regards

Jared

RE: Sending consecutive 7 notification on ble characteristic issue

adnan arshad — Tue, 24 Mar 2020 13:33:24 GMT

I have change in sdk_config NRF_SDH_BLE_GAP_EVENT_LENGTH 6 to 12 but still same results please guide can i send more than 6 consecutive ble notification on same characteristic in nordic ble.