J-Link could not connect to the device (EFR32)#

When using the Wireless Starter Kit main board (WSTK) along with a radio board, you should be able to connect with J-Link RTT Viewer using the parameters in the dedicated section. Your EFR32 should also be detected by Simplicity Studio 5.

If your EFR32 is not detected or you have difficulties connecting with J-Link RTT Viewer, you can check two points:

  • Your WSTK power switch is on "AEM" mode.

  • Your radio board is plugged in correctly (see the following)

Board setup example

CloudFormation Errors#

Permission Denied#

While executing the CloudFormation command to deploy your stack, you have an error showing missing authorization as follows:

<your user> is not authorized to perform: cloudformation:<some action> on resource aws:cloudformation:us-east-1:<some resource> because no identity-based policy allows the cloudformation:<some action> action

It is probably because your IAM user associated to your CLI does not have sufficient permissions. You should ask the person managing your AWS account to help you on this task.

Failed to Create Stack#

CloudFormation stack creates objects and every user inside the same IAM policy has access to those objects. The stack only needs to be created once, and can be used for all your devices. If you try to deploy the CloudFormation stack but some objects already exist with the same name, your stack will not deploy with results like the following:

Waiting for changeset to be created..
Waiting for stack create/update to complete

Failed to create/update the stack. Run the following command
to fetch the list of events leading up to the failure
aws cloudformation describe-stack-events --stack-name NameOfYourStack

To get more details on this error, execute this command: aws cloudformation describe-stack-events --stack-name NameOfYourStack

This command displays all the actions attempted by CloudFormation. While reading the error messages, if you see an error log about an object that already exists then you should check what objects are already created inside your AWS account.

As an example you can see in the following log that the creation of CFSRepublishLambdaRole failed (value of ResourceStatus field) because it already exists (value of ResourceStatusReason field):

"StackId": "arn:aws:cloudformation:us-east-1:78468574544:stack/NameOfYourStack/4a54e4-4583-5435-f548-ad546584dd58",
"EventId": "CFSRepublishLambdaRole-CREATE_FAILED-2022-09-21T14:18:19.899Z",
"StackName": "NameOfYourStack",
"LogicalResourceId": "CFSRepublishLambdaRole",
"PhysicalResourceId": "",
"ResourceType": "AWS::IAM::Role",
"Timestamp": "2022-09-21T14:18:19.899000+00:00",
"ResourceStatus": "CREATE_FAILED",
"ResourceStatusReason": "CFSRepublishLambdaRole already exists in stack arn:aws:cloudformation:us-east-1:560019425582:stack/SidewalkStack/a58745f-5458-5742-125e-65a8b45a25",
"ResourceProperties": "{\"MaxSessionDuration\":\"3600\",\"RoleName\":\"CFSRepublishLambdaRole\",\"Description\":\"Allows IoT to call AWS services on your behalf.\",\"Policies\":[{\"PolicyName\":\"CFSRepublishPolicy\",\"PolicyDocument\":{\"Statement\":[{\"Action\":[\"iot:*\",\"sqs:*\",\"iotwireless:*\",\"logs:*\"],\"Resource\":[\"*\"],\"Effect\":\"Allow\"}]}}],\"AssumeRolePolicyDocument\":{\"Version\":\"2012-10-17\",\"Statement\":[{\"Action\":[\"sts:AssumeRole\"],\"Effect\":\"Allow\",\"Principal\":{\"Service\":[\"\"]},\"Sid\":\"\"}]}}"

You should delete the duplicated resources or rename them.

Registration Errors#

Failing During Device Registration#

Once your device is detected by the registration script, it starts to exchange messages in order to register. During this message exchange, if you see the following errors on your endpoint logs, then your Secure Element Firmware is probably outdated.

<info> data_send send -8
<error> Dispatcher: Message handler returned unexpected result - -8

The Amazon Sidewalk examples require that the EFR32 uses a minimal version of Secure Element firmware depending on the radio board MCUs. See the table below to check your version:

Radio Board MCUs

SE minimal version







You can verify this version in the Simplicity Studio 5 Launcher perspective. If the EFR32 is using an older firmware version, update it. If you do not see Update to 1.2.9 (as shown below), disconnect and re-connect the board until it appears.

Simplicity Studio Secure Firmware update

Time Synchronization#

Once your device is registered, time synchronization between the gateway and the endpoint should take place within a few minutes. If the device does not attempt to synchronize with the gateway, check that your Amazon Echo device is connected to the Internet and localized in the US, then try rebooting your gateway and your endpoint.

Amazon Sidewalk - SoC Hello Neighbor Errors#

When trying out the Hello Neighbor application with FSK radio layer, you may see logs about failing Disco module that resemble the following logs (the device is fully registered and attempts to discover the gateway):

<info> [00132619] App - sidewalk status changed: 1
<info> [00132619] App - registration status: 0, time sync status: 1, link status: 0[00132631] <info> RTC compensation is not supported.
[00132632] <info> swi thread created
[00132632] <info> Set region 1, country: US, num cfg: 2
[00132673] <info> P2P chnl loaded: 7
[00132673] <info> PAN ID loaded: 
[00132673] <info> B9 80 96 21 00 
[00132675] <info> Def mcast retries: 1
[00132675] <info> Pairing state loaded: 0
[00132675] <info> Config version 4
[00132675] <info> init_chnl_seed, chsid:9, seed:FFFFFA610000
[00132676] <info> rnet_mac_disco_init state = 0, req_auth = 0,cur_ev = 00000000
[00132676] <info> min ch symbols ms 151 bcn time ms 167
[00132677] <info> Starting GWD Process in: PASSIVE_SYNC/FFS_MODE
[00132677] <info> rnet_mac_disco_start_sampling state = 1, req_auth = 0, cur_ev = 00000000 f = 00052AC1 r = 0
[00132678] <info> Disco sampling start SUCCESS! state = 2, req_auth = 0, cur_ev = 00000000
[00132679] <info> 900MHz MAC Init: PRB:1 BCN:1 HDR:1, HDR_LORA:0 LDR:0
[00132680] <info> rnet_sec: Loading Setting (key=0xa) not on flash!
[00132682] <error> rnet_sec: File content for 2 mode cannot be trusted!
[00132683] <info> rnet_sec: Loading Setting (key=0x9) not on flash!
[00132685] <error> rnet_sec: File content for 1 mode cannot be trusted!
[00132686] <info> Ring-Net initialized
[00132686] <info> Disco stop sampling success. Time elapsed = 7 ms
[00132686] <info> [MET] B:0 N:0
[00132687] <info> rnet_mac_disco_init state = 1, req_auth = 0,cur_ev = 00000000
[00132687] <info> Starting GWD Process in: PASSIVE_SYNC/FFS_MODE
[00132688] <info> rnet_mac_disco_start_sampling state = 1, req_auth = 0, cur_ev = 00000000 f = 00052AC1 r = 0
[00132688] <info> Disco sampling start SUCCESS! state = 2, req_auth = 0, cur_ev = 00000000
[00132689] <info> Disco active. LSC=0, symb=7490, rx_to_ms=151
[00132690] <info> [MET] B:0 N:0
[00132857] <warning> Disco submodule ended prematurely! ch = 0
[00133025] <warning> Disco submodule ended prematurely! ch = 1
[00133193] <warning> Disco submodule ended prematurely! ch = 2
[00133362] <warning> Disco submodule ended prematurely! ch = 3
[00133530] <warning> Disco submodule ended prematurely! ch = 4

This error is generally linked to a missing or incorrectly plugged-in Semtech board.