Softdevice assert 151994:0

[HAFLN]

I am getting an intermittent "Softdevice assert: 151994:0" error on device initialisation or after the device has run for a period of time. I am using Light Switch Client stock example.

Nordic SDK: nRF5_SDK_15.3.0_59ac345

Nordic Mesh SDK:  nrf5_SDK_for_Mesh_v3.2.0_src

Softdevice: s140_nrf52_6.1.1_softdevice.hex

The device is custom, built on MDBT50Q. 

Sample error log output:

1. <t: 12895576>, app_error_weak.c, 96, Softdevice assert: 151994:0
2. <t: 74659>, app_error_weak.c, 96, Softdevice assert: 151994:0
3. <t: 74453>, app_error_weak.c, 96, Softdevice assert: 151994:0
4. <t: 74629>, app_error_weak.c, 96, Softdevice assert: 151994:0

[ftjandra]

Hi HAFLN,

Did you figure out what was causing the 154516:0 Softdevice assert?

Thanks.

[HAFLN]

Hi Joakim,

I've tried running our code using:

1. nRF5_SDK_16.0.0_98a08e2
2. nrf5_SDK_for_Mesh_v4.0.0_src
3. s140_nrf52_7.0.1_softdevice.hex

Once provisioned the device always fails, the assertion now is 

<t: 77868>, app_error_weak.c, 55, Softdevice assert: 154516:0

and we are getting CAFEBABE:

    0000        movs r0, r0
    20000058    .word 0x20000058
    CAFEBABE    .word 0xCAFEBABE
    4001F500    .word 0x4001F500
    4001F000    .word 0x4001F000
    FFFE0000    .word 0xFFFE0000
    4B81        ldr r3, [pc, #0x204]
    681B        ldr r3, [r3]
    B103        cbz r3, 0x00024C94
    4798        blx r3
    

Could that be another manifestation of the same problem?

EDIT:

I am getting absolutely identical result when building Light Switch On/Off Client Example that came with Mesh SDK 4.0.0 (with zero modifications), loading the on/off client onto the device, provisioning, configuring the on/off client to publish to a group and restarting the device.

[Oleh]

Hi Joakim,,

the MDBT50Q module has a 32MHz XTAL included and it has +-20ppm.

Do you think there is a need do any config in this case?

Best

Oleh

[Joakim Jakobsen]

Thanks. 

As the unmodified light switch example runs without problems on the nRF52, i assume the issue is with your custom board. 

You must have an external 32Mhz crystal with a tolerance of +-40ppm or better if you're going to use BLE Mesh. It's not optional like the LF crystal is. Did you add that to your custom board?

Br, 
Joakim

[HAFLN]

Hi Joakim, thanks for investigating!

1. nrf5_SDK_for_Mesh_v3.2.0_src\examples\light_switch\client\light_switch_client_nrf52840_xxAA_s140_6_1_1.emProject
2. Change preprocessor definitions BOARD_PCA10056 -> BOARD_CUSTOM
3. Copy custom_board.h into includes directory
4. Build and download to the device.
5. Connect to the nRF5x Mesh Switch device using nRF Mesh Android App
6. Provision using No OOB.
7. Configure: bind app key, make one of the two switch elements publish to a group.
8. Disconnect nRF Mesh App from the Node: assertion failure.
9. Reboot the device several times pressing power button: assertion failure.
10. Leave the device working (the only device in the mesh) for a while: assertion failure.

When Segger Embedded Studio Debugger is connected I am getting the following output:

When dead on reboot

<t: 0>, main.c, 318, ----- BLE Mesh Light Switch Client Demo -----
<t: 8768>, main.c, 289, Initializing and adding models
<t: 8820>, mesh_app_utils.c, 65, Device UUID (raw): UUID edited out
<t: 8824>, mesh_app_utils.c, 70, Device UUID : UUID edited out
<t: 74660>, app_error_weak.c, 96, Softdevice assert: 151994:0  

When dead after working for a while

<t: 0>, main.c, 318, ----- BLE Mesh Light Switch Client Demo -----
<t: 8773>, main.c, 289, Initializing and adding models
<t: 8827>, mesh_app_utils.c, 65, Device UUID (raw): UUID edited out
<t: 8831>, mesh_app_utils.c, 70, Device UUID : UUID edited out
<t: 1914032>, app_error_weak.c, 96, Softdevice assert: 151994:0