Can I create a master and slave in one device?

[Peter Verheij]

I would like to create a unit which is intermitting in the master and in the slave role.It should be most of the time "advertising" and waiting for some master to connect to it i.e. slave role.But every now and then it should leave this role and become a master and try to connect to another slave. Can this be done in a single device? wil it need to swap softdevice S110 / S120 every time?

[Carles]

Hi Peter,

Unfortunately at this point Nordic does not offer a single SoftDevice capable of acting both as a master and a slave, so you will have a role assigned depending on which SD you flash (S110 is a slave, S120 is a master).

Regards,

Carles

[Peter Verheij]

Our customer wants us to make a heater-controller for a gas or wood stove ,to be controlled by BT. This controller will controll valves and ventilators ,and the control panel shall be on the user's iPhone or tablet.Now this is obviously a master device so my stove controller shall be slave. Now the best location in a home to place a temperature sensor is not always easy to reach by wires.So why not use a BT temperature sensor?->another slave. And I need a way to get data from the temperature sensor to the stove controller....

So in order to get a system like this i have the following options:

1. place 2 nrf51822 units in the stove controller (1 master and 1 slave) the BT temperature sensor can be an off the shelf unit powered by battery.

2. the stove controller is a master and seeks connection wit a (custom made) temperature sensor which is slave and can also hold data. So this temperature sensor unit acts as a gateway between the various masters in the system.

3. the temp sensor is wired,as it has been several decades.

[Carles]

I can suggest another option:

You could create a custom (or even ANT) link between the temperature sensor and the stove controller. The nRF51 series of chips is capable of concurrently running 2 protocols (ANT and BLE) or sequentially running 2 protocols (custom/Gazell and BLE), and those protocols have full support for master/slave. Since the temperature controller does not need to connect directly to the phone, it doesn't need to use a standard protocol like BLE. That way you would only need 2 ICs instead of 3.

Regards,

Carles

[Ole Morten]

For your application, I'd recommend you to take a look on the S310. This is a softdevice that is able to concurrently keep a BLE link, while being able to communicate with other ANT devices. This softdevice can be used with the latest revision nRF51422 chips.

Another option can also be to keep using S110 for the smartphone connectivity, but use a proprietary connection with the other devices. Be aware however that current softdevice does not allow you to do such proprietary communication while a BLE link is established.

Please contact our sales manager for your area for details on sampling nRF51422, or information future plans for the S110. PM me your location if you don't have his contact information.

[Peter Verheij]

I'm not particularly happy with the suggested solutions for a couple of reasons:

1. a BTLE temperature sensor is an off the shelf product.I see it as a headstart :we can develop our own but we must'nt
2. Its one more new thing we have to learn about ,and we're just starting with BT! That's all a lot of learning hours on a project not particularly big.