Master Control Panel vs Gatttool

RE: Master Control Panel vs Gatttool

kmorris — Wed, 05 Jul 2017 19:35:45 GMT

Found it. HRS example was requesting MAX_MTU size. Since I don't yet need that and my laptop BLE dongle apparently does not yet support that, I have instead changed gatt configuration to the default, so it doesn't even attempt to issue an MTU request.

ble_cfg.conn_cfg.params.gatt_conn_cfg.att_mtu = BLE_GATT_ATT_MTU_DEFAULT; //NRF_BLE_GATT_MAX_MTU_SIZE;

RE: Master Control Panel vs Gatttool

kmorris — Fri, 30 Jun 2017 21:29:56 GMT

Ok.. dug out sniffer. Looks like it might be hanging up on the MTU exchange. The BLE dongle that I'm using with gatttool doesn't seem to support it.

Gatttool + Pluggable BLE dongle

2222	56.084918000	Slave	Master	BLE Data	35	LL Control PDU: unknown
2223	56.121044000	Master	Slave	BLE Data	28	LL Control PDU: LL_UNKNOWN_RSP

versus: nRF Connect App (instead of Master Control Panel cause I only have one nRF51 at my desk at the moment)

977	29.926437000	Master	Slave	BLE Data	32	LL Control PDU: LL_VERSION_IND
978	29.945158000	Slave	Master	ATT	33	Rcvd Exchange MTU Request, Client Rx MTU: 158
981	29.996311000	Slave	Master	BLE Data	35	LL Control PDU: unknown
982	30.014089000	Master	Slave	ATT	33	Rcvd Exchange MTU Response, Server Rx MTU: 158
983	30.034285000	Master	Slave	ATT	33	Rcvd Exchange MTU Response, Server Rx MTU: 158

With SDK13 do I need to have a default MTU set in case the dongle doesn't support the exchange? Is this not currently implemented in the HRS example?

RE: Master Control Panel vs Gatttool

Jørgen Holmefjord — Fri, 30 Jun 2017 11:44:48 GMT

Master control panel should not be doing anything special other than handling the BLE requests. I can't answer about what gatttool does. Could you provide a sniffer trace to see if there are any unhandled requests on the air?