why report error with BLE_ERROR_NO_TX_BUFFERS(0x3004)

[leif]

Hi, My project need to transmit mass data(maybe over 64kB)to APP once.But the total transmiting time is better not over 30Min.i use your example nRF51_SDK_8.1.0_b6ed55f\examples\ble_peripheral\ble_app_uart.But i meet a problem that calling function ble_nus_string_send() with time interval 200ms, it will report error with BLE_ERROR_NO_TX_BUFFERS(0x3004) after runing dozens of times successfully. if modify time interval 300ms, it run ok all the time. why it report error with BLE_ERROR_NO_TX_BUFFERS(0x3004)? my code will check if return value is NRF_SUCCESS after calling ble_nus_string_send(). if it is NRF_SUCCESS, it will transmit next packet data. part code is as below: if(err_code ==NRF_SUCCESS) { err_code = ble_nus_string_send(&m_nus, data_array, 20);

       if (err_code != NRF_ERROR_INVALID_STATE)
	 {
		          APP_ERROR_CHECK(err_code);
        }

}. i can't search which give error value with BLE_ERROR_NO_TX_BUFFERS in code. is bottom code give it? Another, is select using ble_uart case to tranmist mass data ok because of its limited size 20Byte packet each time? if not, do you give your advice? something like DFU, it can tranmist mass image packet. Thank you.

[leif]

i see the comment for function ble_nus_string_send(ble_nus_t * p_nus, uint8_t * p_string, uint16_t length) as @retval NRF_SUCCESS If the string was sent successfully. Otherwise, an error code is returned. returning NRF_SUCCESS mean that the string was sent successfully. it should was sent to the peer and free TX buffer. then the function call again should not result to error BLE_ERROR_NO_TX_BUFFERS . unless returning NRF_SUCCESS mean that quque TX buffer successfully and quque up transimiting data.