CC2652R7: Adding mesh stack to central/peripheral configuration

Hello Ola,

I would suggest looking at the multi_role example (<SDK>\examples\rtos\CC26X2R1_LAUNCHXL\ble5stack\multi_role) and port the simple_mesh_node example functionalities to it (<SDK>\examples\rtos\CC26X2R1_LAUNCHXL\ble5stack\simple_mesh_node).

We also have training material on TI Bluetooth Mesh Fundamentals here, that could be useful.

Hope it helps,

David.

Thanks for your response.

However, as far as I can tell, the simple_mesh_node example handles a statically provisioned mesh node, not a mesh proxy client.

I do understand that your examples are useful for developing the actual mesh nodes, but as I tried to explain, I am developing the mesh proxy client, not the mesh node itself.

I did use the multi role example for enabling both central and peripheral behaviour, but as I explained, I cannot have this defined and still use the mesh stack.

Any other help or pointers greatly appreciated.

Regards,

/Ola

Hello Ola,

It is possible to do peripheral + central + mesh relay, and you would have to take the mesh example as reference (which is based on peripheral + mesh) and modify the peripheral portion to be peripheral + central. This will indeed require additional efforts to modify the code.

Regarding the provisioned mesh, I would suggest to take a look at this material.

I am still reviewing what other path could be consider here.

Let me know if it helps please.

David.

Again, thank you for your effort.

However, in my use case the Mesh nodes I am interfacing are already provisioned, so provisioning is not an issue.

As a central proxy client, I do need to have access to the mesh stack since the proxied group messages from the mesh network must be decrypted and unsegmented according to the mesh standard.

In my understanding, the only way to get access to the TI Mesh stack is to check the Mesh checkbox in sysconfig but when I do this, the BLE Device Role is changed, no longer featuring the Central role I need.

Also, when building the mesh examples, the code footprint is huge, so I do not need the full stack, rather just the encryption/decryption/segmentation.

I am quite aware of the Mesh mechanism so you really don't need to send any further links that explain it. The Mesh profile BLE spec covers it all.

Regards,

/Ola

Hello Ola,

Understand.

Currently we do not have any example that supports that implementation.

However we could assist you in specific questions you may have while implementing it on your side.

BR,

David.

Some help would be greatly appreciated.

I've managed to isolate a number of files needed in order for client mesh handling to work sufficiently but am getting a number of build warnings that I can't seem to get rid of.

Files added from the mesh stack:

utils

aes_ccm

cmac_mode

simplelink_crypto

buf

crypto

Also added the required include folders and the following set of defines:
CONFIG_BT_MESH_PROXY
CONFIG_BT_MESH_SUBNET_COUNT=2
CONFIG_BT_MAX_CONN=2
CONFIG_BT_MAX_PAIRED=2
CONFIG_BT_MESH_MODEL_GROUP_COUNT=2
CONFIG_BT_MESH_MODEL_KEY_COUNT=1
CONFIG_ATOMIC_OPERATIONS_BUILTIN
CONFIG_BT_MESH_TX_SEG_MAX=5
BT_MESH_TX_SDU_MAX=30
ZEPHYR_KERNEL_BUILD
CONFIG_ARM

Functions I am using include:
bt_mesh_subnet_add

bt_mesh_subnet_get

bt_mesh_net_encode

bt_mesh_net_decode

bt_ccm_decrypt

The build warnings I am getting:

C:/ti/simplelink_cc13xx_cc26xx_sdk_6_41_00_17/source/ti/mesh/zephyr/include\kernel.h:84:9: warning: 'z_tick_get' macro redefined [-Wmacro-redefined]
#define z_tick_get k_uptime_get
^
C:/ti/simplelink_cc13xx_cc26xx_sdk_6_41_00_17/source/ti/mesh/zephyr/include\sys_clock.h:200:9: note: previous definition is here
#define z_tick_get() (0)

Any help greatly appreciated.

Regards,

/Ola

During the day, a new related problem has turned up.

Using the encryption/decryption mesh files works well, using the BLE stack only as central, but when also using the peripheral BLE role, the BLE stack seems to get corrupted, at least if it connects as peripheral after using the encryption mechanisms.

Working scenario is:

Bond with peripheral app (as peripheral role) - works. Peer address correct every time

Connect with proxy server (as central role)- works

Encrypt and send whitelist message. Start receiving notifications- works

Not working scenario is:

Connect with proxy server (as central role)- works

Encrypt and send whitelist message. Start receiving notifications- works

Bond with peripheral app (as peripheral role) - does not work.

When checking the peer address from the connection, it is all garbled data and gives a separate address each connection attempt.

Now, if I remove the call to the function that creates the whitelist message using the encryption mesh functions, I can connect to both central and peripheral again.

Thus I suspect that the mesh files somehow corrupts the execution context of the BLE stack.

Any ideas how to pinpoint this? I assume that I am missing some important properties of how the mesh stack is supposed to be setup.

Regards,

/Ola

Hello Ola,

For the first issue, have you been able to locate the files where #define z_tick_get is defined? It seems there is a definition conflict in sys_clock.h and kernel.h. Can you look for these files and see if at some point there should be a #if () to select to use one or the other? So that both are not build together.

Do you have a Bluetooth sniffer to understand better what is happening over the air during peripheral bonding?

Could you please specify where/how you are erasing the whitelist message?

Some code-snippets of what you are modifying and consider that could provide more hints could help, if its possible to share.

BR,

David.

Hello Ola,

For the first issue, have you been able to locate the files where #define z_tick_get is defined? It seems there is a definition conflict in sys_clock.h and kernel.h. Can you look for these files and see if at some point there should be a #if () to select to use one or the other? So that both are not build together.

Do you have a Bluetooth sniffer to understand better what is happening over the air during peripheral bonding?

Could you please specify where/how you are erasing the whitelist message?

Some code-snippets of what you are modifying and consider that could provide more hints could help, if its possible to share.

BR,

David.