Hello.
I want to know maximum number of 'BLE MESH' connect,
Could you teach maximum number in 52840?
also
Could you teach number of evaluation in 52840?
Thank you.
Hi,
The team said the maximum is limited by the chip memory sources. It depends on which cache size they can allocate for the network configuration. It should consider the other configuration options like the number of elements, model instances, keys, application memory consumption, etc. It is possible to give theoretical digits based on different parameters (for instance unicast addresses). It needs to understand the use case then calculate the number of resources necessary for the use case and after that take a look at the concrete chip to understand whether it is possible to use for this use case or doesn't. In the opposite way, it is possible to give the only theoretical assumption that correlates with real-life quite weak.
CONFIG_BT_MESH_CRPL is used to configure the real size of the cache in Zephyr. Currently, this is 10. If the device does not have the capability to story sequence numbers for incoming messages from the appropriate device it cannot pass the message on a layer above.
-Amanda
Hi,
The team said the maximum is limited by the chip memory sources. It depends on which cache size they can allocate for the network configuration. It should consider the other configuration options like the number of elements, model instances, keys, application memory consumption, etc. It is possible to give theoretical digits based on different parameters (for instance unicast addresses). It needs to understand the use case then calculate the number of resources necessary for the use case and after that take a look at the concrete chip to understand whether it is possible to use for this use case or doesn't. In the opposite way, it is possible to give the only theoretical assumption that correlates with real-life quite weak.
CONFIG_BT_MESH_CRPL is used to configure the real size of the cache in Zephyr. Currently, this is 10. If the device does not have the capability to story sequence numbers for incoming messages from the appropriate device it cannot pass the message on a layer above.
-Amanda
I am considering the following specifications.
・The network configuration consists of 101 units connected by a BLE MESH.
・All 101 units are equipped with nRF52840 and running the same program.
・One unit is a host and 100 units are clients.
・Once a day, 100 clients send 255 bytes of data to the host all at once.
I would like to know about the following.
・Is it possible to calculate the resources required?
・Is it possible to realize the specification with nRF52840?
Hi,
From our expert:
You can do this with Bluetooth mesh, yes. One reason for doing it with Bluetooth mesh is if the devices are spread out so that you do not all have direct radio access to what you call "host". However, you may want to do something smart, if what you call "clients" are not mains powered. Either by adding mains-powered relay nodes or by all nodes waking up at the same time of day, in order for the network to be functional while the nodes send the data. 255 bytes per day should be well within what the Bluetooth mesh network can handle, although with 100 nodes I guess it may take some time to get it all transferred.
We do have numbers for nRF5 SDK, with one gateway and 32 nodes. The throughput on the gateway, for SAR acknowledged messages, is then 1.9 kbps, or around 240 bytes per second, which means around one second per device. With 100 devices, if they all send at the same time, the throughput would probably go down, giving a couple or maybe more seconds per device on average. Numbers for nRF Connect SDK should be similar, this is mostly limited by the technology (Bluetooth mesh) and the configuration of the network, and not limited by the specific implementation.
-Amanda