Hi
I have two DKs, previously they work well, however, after I add the nRF21540 FEM on each DK, I always receive this in my central device:
00> Connection (606) - Central Tx Power = 8 00> [00:10:15.344,398] <err> central_uart: Stop LE scan failed (err 0) 00> [00:10:15.594,660] <wrn> bt_conn: conn 0x20012e08 failed to establish. RF noise? 00> [00:10:15.594,956] <wrn> central_uart: Security failed: C9:94:E8:62:AE:97 (random) level 1 err 9 00> [00:10:15.594,970] <err> bt_gatt_dm: Discover failed, error: -128. 00> [00:10:15.594,976] <err> central_uart: could not start the discovery procedure, error code: -128 00> [00:10:15.595,042] <wrn> central_uart: Pairing failed conn: C9:94:E8:62:AE:97 (random), reason 9 00> [00:10:15.595,156] <wrn> central_uart: MTU exchange failed (err 14) 00> [00:10:15.595,253] <inf> central_uart: Disconnected: C9:94:E8:62:AE:97 (random), reason 0x3e 00> [00:10:15.601,036] <inf> central_uart: Filters matched. Address: C9:94:E8:62:AE:97 (random) connectable: 1 00> [00:10:15.624,196] <inf> central_uart: Connected: C9:94:E8:62:AE:97 (random) 00> PHY update requested (2M) 00> Connection param update requested (interval=) 00> Actual Tx Power: 8 00> Connection (608) - Central Tx Power = 8 00> [00:10:15.625,359] <err> central_uart: Stop LE scan failed (err 0) 00> [00:10:15.875,622] <wrn> bt_conn: conn 0x20012e08 failed to establish. RF noise? 00> [00:10:15.875,918] <wrn> central_uart: Security failed: C9:94:E8:62:AE:97 (random) level 1 err 9 00> [00:10:15.875,932] <err> bt_gatt_dm: Discover failed, error: -128. 00> [00:10:15.875,938] <err> central_uart: could not start the discovery procedure, error code: -128 00> [00:10:15.876,004] <wrn> central_uart: Pairing failed conn: C9:94:E8:62:AE:97 (random), reason 9 00> [00:10:15.876,118] <wrn> central_uart: MTU exchange failed (err 14) 00> [00:10:15.876,216] <inf> central_uart: Disconnected: C9:94:E8:62:AE:97 (random), reason 0x3e 00> [00:10:15.893,827] <inf> central_uart: Filters matched. Address: C9:94:E8:62:AE:97 (random) connectable: 1 00> [00:10:15.924,658] <inf> central_uart: Connected: C9:94:E8:62:AE:97 (random) 00> PHY update requested (2M) 00> Connection param update requested (interval=) 00> Actual Tx Power: 8 00> Connection (610) - Central Tx Power = 8 00> [00:10:15.925,820] <err> central_uart: Stop LE scan failed (err 0) 00> [00:10:16.176,084] <wrn> bt_conn: conn 0x20012e08 failed to establish. RF noise? 00> [00:10:16.176,380] <wrn> central_uart: Security failed: C9:94:E8:62:AE:97 (random) level 1 err 9 00> [00:10:16.176,394] <err> bt_gatt_dm: Discover failed, error: -128. 00> [00:10:16.176,400] <err> central_uart: could not start the discovery procedure, error code: -128 00> [00:10:16.176,466] <wrn> central_uart: Pairing failed conn: C9:94:E8:62:AE:97 (random), reason 9 00> [00:10:16.176,580] <wrn> central_uart: MTU exchange failed (err 14) 00> [00:10:16.176,677] <inf> central_uart: Disconnected: C9:94:E8:62:AE:97 (random), reason 0x3e 00> [00:10:16.180,107] <inf> central_uart: Filters matched. Address: C9:94:E8:62:AE:97 (random) connectable: 1 00> [00:10:16.208,609] <inf> central_uart: Connected: C9:94:E8:62:AE:97 (random) 00> PHY update requested (2M) 00> Connection param update requested (interval=) 00> Actual Tx Power: 8 00> Connection (612) - Central Tx Power = 8 00> [00:10:16.209,771] <err> central_uart: Stop LE scan failed (err 0) 00> [00:10:16.215,729] <inf> central_uart: Data Rate: 0.00 bps (0.00 bytes/s) 00> [00:10:16.215,889] <inf> central_uart: avg_rate = 0.000000 00> 00> [00:10:16.215,897] <inf> central_uart: RXRX = 127 00> 00> Adaptive Tx power selected = 0 00> [00:10:16.460,035] <wrn> bt_conn: conn 0x20012e08 failed to establish. RF noise? 00> [00:10:16.460,331] <wrn> central_uart: Security failed: C9:94:E8:62:AE:97 (random) level 1 err 9 00> [00:10:16.460,345] <err> bt_gatt_dm: Discover failed, error: -128. 00> [00:10:16.460,351] <err> central_uart: could not start the discovery procedure, error code: -128 00> [00:10:16.460,417] <wrn> central_uart: Pairing failed conn: C9:94:E8:62:AE:97 (random), reason 9 00> [00:10:16.460,531] <wrn> central_uart: MTU exchange failed (err 14) 00> [00:10:16.460,547] <wrn> central_uart: ATT error code: 0x0E 00> [00:10:16.460,660] <inf> central_uart: Disconnected: C9:94:E8:62:AE:97 (random), reason 0x3e 00> [00:10:16.483,252] <inf> central_uart: Filters matched. Address: C9:94:E8:62:AE:97 (random) connectable: 1 00> [00:10:16.550,006] <inf> central_uart: Connected: C9:94:E8:62:AE:97 (random) 00> PHY update requested (2M) 00> Connection param update requested (interval=) 00> Actual Tx Power: 8 00> Connection (614) - Central Tx Power = 8 00> [00:10:16.551,169] <err> central_uart: Stop LE scan failed (err 0) 00> [00:10:16.801,432] <wrn> bt_conn: conn 0x20012e08 failed to establish. RF noise? 00> [00:10:16.801,728] <wrn> central_uart: Security failed: C9:94:E8:62:AE:97 (random) level 1 err 9 00> [00:10:16.801,742] <err> bt_gatt_dm: Discover failed, error: -128. 00> [00:10:16.801,748] <err> central_uart: could not start the discovery procedure, error code: -128 00> [00:10:16.801,814] <wrn> central_uart: Pairing failed conn: C9:94:E8:62:AE:97 (random), reason 9 00> [00:10:16.801,928] <wrn> central_uart: MTU exchange failed (err 14) 00> [00:10:16.802,026] <inf> central_uart: Disconnected: C9:94:E8:62:AE:97 (random), reason 0x3e 00> [00:10:16.809,402] <inf> central_uart: Filters matched. Address: C9:94:E8:62:AE:97 (random) connectable: 1 00> [00:10:16.834,703] <inf> central_uart: Connected: C9:94:E8:62:AE:97 (random) 00> PHY update requested (2M) 00> Connection param update requested (interval=) 00> Actual Tx Power: 8 00> Connection (616) - Central Tx Power = 8 00> [00:10:16.835,865] <err> central_uart: Stop LE scan failed (err 0) 00> [00:10:17.086,128] <wrn> bt_conn: conn 0x20012e08 failed to establish. RF noise? 00> [00:10:17.086,424] <wrn> central_uart: Security failed: C9:94:E8:62:AE:97 (random) level 1 err 9 00> [00:10:17.086,438] <err> bt_gatt_dm: Discover failed, error: -128. 00> [00:10:17.086,444] <err> central_uart: could not start the discovery procedure, error code: -128 00> [00:10:17.086,510] <wrn> central_uart: Pairing failed conn: C9:94:E8:62:AE:97 (random), reason 9 00> [00:10:17.086,624] <wrn> central_uart: MTU exchange failed (err 14) 00> [00:10:17.086,721] <inf> central_uart: Disconnected: C9:94:E8:62:AE:97 (random), reason 0x3e 00> [00:10:17.104,005] <inf> central_uart: Filters matched. Address: C9:94:E8:62:AE:97 (random) connectable: 1 00> [00:10:17.131,498] <inf> central_uart: Connected: C9:94:E8:62:AE:97 (random) 00> PHY update requested (2M) 00> Connection param update requested (interval=) 00> Actual Tx Power: 8 00> Connection (618) - Central Tx Power = 8 00> [00:10:17.132,661] <err> central_uart: Stop LE scan failed (err 0) 00> [00:10:17.216,020] <inf> central_uart: Data Rate: 0.00 bps (0.00 bytes/s) 00> [00:10:17.216,177] <inf> central_uart: avg_rate = 0.000000 00> 00> [00:10:17.216,185] <inf> central_uart: RXRX = 127
Whether the amplifier cause this problems? What is RF noise here? Could you give me some advice?