nRF51822 master-Slave disconnect reason,hci ERROR code:0x003e

Recently in a customer to the master-slave module, based on the S130, a little farther away from the connection will appear immediately after the phenomenon of disconnection,

Traced the reason, given the HCI Error code is 0x003e, for the moment do not know what the ghost, check out a post on the Internet, explained as follows:

Disconnect reason 0x3e Hci_error_code_conn_failed_to_establish

• I use TI CC2640 master machine, mobile phone do from the machine for data transmission, sometimes found TI as a host connection on the phone, immediately there will be disconnected events, after tracking, found that the reason for disconnection is

  0x3e Hci_error_code_conn_failed_to_establish, but prior to this there was a connection established event Gap_link_established_event generated,

  Ask IT staff to see why this is happening and how to deal with preventing such problems.

• There are related posts on TI e2e https://e2e.ti.com/support/wireless_connectivity/f/538/t/377682

  A "Failed to establish" (0X3E) error occurs if the master was unable to receive a packet from the slave within the first 6 Connection events after sending a connection request. This could is caused a number of reasons. Here is a few possibilities:

  • The RF performance on one or both devices are not good, so the slave either never receives the connection request, or the M Aster never receives any packets from the slave during the first 6 connection events. The RF performance could is bad due to a failed CRC, collision or maybe the devices is just out of range.
  • There could is a timing issue in either device. If the link layer clock on either device isn't running at 32.768kHz (within the tolerance set using the Hci_ext_setscacmd function Default is +/-50PPM) then the timing would be off and the slave might not being listening at the correct time to receive the M Aster ' s packets.
  • If The slave device is advertising with the whitelist filter policy set to Gap_filter_policy_white_conor Gap_filter_policy _white then the slave would ignore the connection from the master and continue advertising normally, and the master would ge T the 0x3e error since it does not receive any packets from the slave during the first 6 connection events.

nRF51822 master-Slave disconnect reason,hci ERROR code:0x003e