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MSalm.2
MSalm.2
Visitor II
April 1, 2026
Question

Unable to Connect ST67W611 (T01) to AWS IoT via MQTT

  • April 1, 2026
  • 0 replies
  • 110 views

I am working on a project that uses the ST67W611 for cloud connectivity, but I am experiencing some issues when trying to connect to AWS IoT Core.

Note: The NCP is already flashed with the T01 binary.

The AWS endpoint is correct — for the sake of this question, let’s assume it is:
xxxxxx-something.amazonaws.com.

What Works

Broker: test.mosquitto.org

I am able to publish data to the broker and receive data from it when using test.mosquitto.org.

However, I am now trying to get it working so that our custom device can connect to AWS IoT Core.

MQTT Configuration

(This is my current MQTT configuration.)

 

#define MQTT_BROKER 	"xxxxxxxxxxxxxxxxxxus-west-1.amazonaws.com"
#define MQTT_PORT 	8883
#define MQTT_CLIENT_ID 	"Thing01"
#define MQTT_USE_TLS 	4
#define MQTT_KEEPALIVE_S 60

static const char s_aws_ca_cert[] =
 "-----BEGIN CERTIFICATE-----\r\n"
 "Conten........\r\n"
 "Conten........\r\n"
 .....
 "-----END CERTIFICATE-----\r\n"
static const char s_aws_client_cert[] =
 "-----BEGIN CERTIFICATE-----\r\n"
 "Conten........\r\n"
 "Conten........\r\n"
 .....
 "-----END CERTIFICATE-----\r\n"

static const char s_aws_private_key[] = 
 "-----BEGIN RSA PRIVATE KEY-----\r\n"
 "Conten........\r\n"
 "Conten........\r\n"
 "-----END RSA PRIVATE KEY-----\r\n"

static W6X_MQTT_Connect_t s_mqtt_cfg = {
 .HostName = MQTT_BROKER,
 .HostPort = MQTT_PORT,
 .MQClientId = MQTT_CLIENT_ID,
 .KeepAlive = MQTT_KEEPALIVE_S,
 .Scheme = MQTT_USE_TLS,
 .SNI_enabled = 1, 
 .CACertificateContent = (char *)s_aws_ca_cert,
 .CertificateContent = (char *)s_aws_client_cert,
 .PrivateKeyContent = (char *)s_aws_private_key,

	.CACertificateName = "aws_ca.pem",
	.CertificateName = "aws_client.crt",
	.PrivateKeyName = "aws_client.key",
};

W6X_MQTT_Init(&s_recv_data);

W6X_MQTT_Configure(&s_mqtt_cfg);

Device Logs:
--------------- ST67W6X info ------------
ST67W6X MW Version: 1.2.0
AT Version: 1.0.0
SDK Version: 2.0.97
Wi-Fi MAC Version: 1.6.44
BT Controller Version: 1.6.121
BT Stack Version: 1.10.70
Build Date: Nov 19 2025 11:32:00
Module ID: C6AFDBD111400004 (-B)
BOM ID: 2
Manufacturing Year: 2025
Manufacturing Week: 16
Battery Voltage: 3.308 V
Trim Wi-Fi hp: 6,6,6,6,6,6,6,6,7,7,7,8,8,8
Trim Wi-Fi lp: 5,6,6,7,7,8,8,8,9,9,9,10,10,10
Trim BLE: 5,5,5,6,7
Trim XTAL: 37
MAC Address: 40:82:7b:03:77:84
Anti-rollback Bootloader: 0
Anti-rollback App: 0
-----------------------------------------
WiFi: Connecting to "F1-FLOOR"...
WiFi: Associated
File content is different: Delete operation requested
File copied to NCP
File content is different: Delete operation requested
File copied to NCP
File content is different: Delete operation requested
File copied to NCP
WiFi: IP ready — 192.168.100.xxx
MQTT: Connecting to xxxxxxxxxxxxxxxxxx.ats.iot.us-west-1.amazonaws.com:8883...
MQTT: Connected and subscribed to "test/cmd"
MQTT: Ready to publish on "test/data"
MQTT:Data Published.

Issues

  1. Every time the device boots up, it performs the following operation repeatedly:


File content is different: Delete operation requested
File copied to NCP
File content is different: Delete operation requested
File copied to NCP
File content is different: Delete operation requested
File copied to NCP

Even though I am not changing anything, this process happens on every boot.

  1. There is no data appearing on the AWS side.

Note: I have already tested AWS connectivity using a test script written in Python with the Paho MQTT library, and it works correctly. Therefore, there does not appear to be an issue on the AWS side.

 

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