sd_ble_gatts_hvx copy data？

[Stayhungry]

The question I mentioned here

When using ble_gatts_hvx to send data, only send data pointer and length to softdevice, and softdevice did not copy these data to the softdevice's buffer, so even if I receive NRF_SUCCESS can not modify the pointer to the memory.

I want to be able to confirm one thing, that is to say I need to do this in order for my data to be sent securely:

Suppose p_buffer points to data at 0x20000000 .

1, ble_gatts_hv (p_buffer);

2, concerned NRF_SUCCESS, but still can not be modified the contents of 0x20000000

3, BLE_GATTS_EVT_HVN_TX_COMPLETE event, view hvn_tx_complete->count to confirm just how many times have been successfully sent, confirm before you can modify 0x20000000

Is that right?

[Sigurd]

Hi,

With ble_gatts_hvx() the data is copied to the internal SoftDevice ATT database/table (see this Message Sequence Chart). So after you get NRF_SUCCESS, you can modify your own buffer, but you cant modify the internal SD buffer. i.e. you can modify p_buffer after NRF_SUCCESS

[Stayhungry]

Thanks,Sigurd.You explain very clearly