In past I try to solve this problem:
https://devzone.nordicsemi.com/f/nordic-q-a/51249/state-chaneged-flags
Now I have new informations about this problem.
Using hardware:
Testing on hardware moduls ebyte e73-2g4m08s1c and fanstel bt-840 which contains NRF-52840.
this moduls have onboard or external antenna
Tested using SDK:[1]
-nRF5_SDK_for_Thread_and_Zigbee_v3.2.0
-nRF5_SDK_for_Thread_and_Zigbee_v3.1.0
Project examples:[2]
-simple coap client
-simple coap server
-dfu client + iot coap
Size of network:[3]
2 - 8 nodes
verifyed through thread topology monitor
nodes are in one room, two furthest distance is 1-6 meters
Count of nodes which is unstable[4]
count of unstable / size of network
sometimes [2 / 2]
sometimes [1 / 2]
sometimes [1 / 3]
sometimes [4 / 5]
sometimes [2-3 / 8]
OT DEVICE ROLES:[5]
role number of role
OT_DEVICE_ROLE_DISABLED 0
OT_DEVICE_ROLE_DETACHED 1
OT_DEVICE_ROLE_CHILD 2
OT_DEVICE_ROLE_ROUTER 3
OT_DEVICE_ROLE_LEADER 4
Time to go UNSTABE[6]
sometimes 1min, sometimes 5min, sometimes more...
1-30 min
Desctiption of behaviour:
-I create THREAD network using some example[1] from SDK [2]
-nodes create THREAD mesh network [3]
-after time[6] some nodes[4] go from ROLE 2 or 3 or 4 to ROLE 1 [5]
-sometimes one of nodes in ROLE 1 go to ROLE 4 and pbobably create separate THREAD mesh network and others join
-normally nodes which is unstable stay in ROLE 1 unless is device restarted
Other informations:
-is used DRV TIMER 2
-is used UART 2
-set Transmit Power to +8dBm
-thread CLI init is not call becouse need use these pins for my UART
- I use COAP protocol to comunicate with NCP
-NCP never have this problem
