Max Slaves in star network with nrf51822?

[ethan schneider]

Hi,

I am trying to create a star network with 12-16 slaves and one master.

The master would be a nrf51822 and the slaves nRF8001/2.

The slaves would not transmit any data besides "I'm here".

Is this possible with these chips?

[Pål Håland]

Hi Ethan,

The maximum number of Slaves that the S120 can be connected to is 8, if you don't have to be connected at all time, but just transmit data that have not been sent since the last connection, then it should not be that big issue. You can only have 8 addresses in the whitelist at the same time, so you could implement a iterator or something to select what devices you would like to connect to.

If you don't even require a connection, then you could just use some advertising data, and service uuid, and just scan for the devices with the S120 nrf51822.

BR Pål

[ethan schneider]

Hi Pal,

Thanks for the response.

Could you clarify what you mean by S120?

Also, what state would the nrf8001/2 have to be in to be seen if the 51822 would just scan for them? Battery Life is a key component of my design so I would like for them to be in sleep mode for as long as possible.

[Pål Håland]

S120 is 8 link central softdevice for the nrf51822. http://www.nordicsemi.com/eng/Products/Bluetooth-R-low-energy/nRF51822

Not sure what you mean by state for the nrf51822 to find them, but as long as they are advertising it should be able to find them.

[David Edwin]

The nRF8001 should be in the ACI Connect/ACI Broadcast state and ideally you should use the ACI Broadcast state to minimize power consumption. In this state the nRF51 with the S120 should be able to scan for the nRF8001s

[ethan schneider]

Thanks for the advice!

Any idea what current is drawn when the nRF8001 is in this state?