BLE high bandwidth bulk transfer from Client to Server

RE: BLE high bandwidth bulk transfer from Client to Server

Kenneth — Tue, 16 Apr 2019 11:46:31 GMT

Hi, I would think what you want to do is similar to an DFU update (where a mobile phone try to send a large amount of data to update the firmware of the device). I suggest you look at that.

Best regards,
Kenneth

RE: BLE high bandwidth bulk transfer from Client to Server

Ted Herman — Mon, 15 Apr 2019 15:21:56 GMT

I was able to get the suggested idea of having the scanner register a service, and the advertiser, upon BLE_GAP_EVT_CONNECTED event should initiate ble_db_discovery_start(), sort of working.

However, it does not work if the advertiser stops advertising -- by calling sd_ble_gap_adv_stop() in the handler of the connected event. The discovery appears to complete only if the advertising is not stopped.

Why is this?
Is there an appropriate time to stop advertising?

RE: BLE high bandwidth bulk transfer from Client to Server

Ted Herman — Sat, 13 Apr 2019 10:13:32 GMT

Does that mean that the scanner should call sd_ble_gatts_service_add() to register a service UUID and that the advertiser, upon an BLE_GAP_EVT_CONNECTED event should initiate ble_db_discovery_start() to later get handles to the scanner's service characteristics when the callback to discovery handler occurs?

RE: BLE high bandwidth bulk transfer from Client to Server

Fred — Sat, 13 Apr 2019 08:20:43 GMT

In BLE the role of Client and Server are separate from the roles of Scanner/Master and Advertiser/Peripheral, in other words, a Peripheral can just as well be a client. See this where it is explained as well. So the mechanism used by the Peripheral to notify its Client in the example you mention can just as well be used by the Master. This means that the Peripheral discovers the service and relevant characteristic at the Master and registers for the notification.