send data more than 20 byte via ble_nus_string_send() nRF51 SDK 9

[Mikhail]

I want to send some data more than 20 bytes. I use ble_nus_string_send(&m_nus, tx_stuffed, 10); 3 times.

In the advertizer.c in the function on_ble_evt I insert code

case BLE_EVT_TX_COMPLETE: 
        b_ble_tx_complette = true;
        break;

But after first use

ble_nus_string_send(&m_nus, tx_stuffed, 10);

I don't receive my flag b_ble_tx_complette equal true; I can send 3 times

ble_nus_string_send(&m_nus, tx_stuffed, 20);
ble_nus_string_send(&m_nus, tx_stuffed + 20, 20);
ble_nus_string_send(&m_nus, tx_stuffed + 40, 20);

with success but without flag b_ble_tx_complette set. Why?

[Mikhail]

I think, I decided this case. I don't should use a

while (flag == 0);

when I wait this flag.

I should wait this flag in the event and call from this event next sending.

[Hung Bui]

I don't think you should wait for any flag, simply start sending if you have data, or if you already have data need to send, send it when you receive BLE_EVT_TX_COMPLETE event.

You get the return code for each command by doing like this

err_code = ble_nus_string_send(&m_nus, tx_stuffed, 10);

Then check the err_code after the call.