About S130 central and peripheral roles switching

[Vincent Hsu]

Hi Nordic：

I have two questions about SoftDevice s130：

Device A,B,C,D are using s130.

1. When this device (called A) is a peripheral and connected with a tablet through BT, when this device (A) also needs to connect to other same type devices (called B, C, D….) at the same time, can I use the s130 to make this device (A) dynamically become a central?

2. When three same type devices (called A,B,C) connect to each other (no tablet among) with A is central and B,C are peripherals where A and B,C can transmit data to each other.

In this case, if I want B and C can transmit data to each other, can I use S130 to immediately change each other’s roles, such as B becomes central, A,C becomes peripherals; besides, how long it takes for this converting? The prerequisite is A,B,C are working well.

[Petter Myhre]

The S130 SoftDevice supports concurrent Central and Peripheral role. You don't need to switch.

1. Device A can be connected to one central(tablet) as a peripheral, and three peripherals(B,C,D) as a central.

2. Then B or C must disconnect from A. Lets say B. B must to start advertise, and C must start to scan. When they enter connection, B will be the peripheral and C will be the central. Diffucult to say how much time the operation will take, depends on the advertising interval and scan window.

You could also have a setup where A(central) is connected to B(peripheral), B(central) is connected to C(peripheral) and C(central) is connect to A(peripheral).

[Petter Myhre]

There is no need to switch. You can be central and peripheral at the same time. We have an experiemental example for the S130 in our latest SDK, v9.0.0, check out examples\ble_central_and_peripheral\experimental\ble_app_hrs_rscs_relay