mqtt connect error

[octvargas]

Hello, 

So I'm trying to modify the mqtt_simple sample program to connect to azure iot

I've modified the code in a few ways but when I went to run the program it gave me this error

Which from my understanding is a failure to connect w/ the mqtt client

and the mqtt_connect error comes from the mqtt.h/c file which is an error of  ENOMEM (err no memory??) in the tx_buf or the rx_buf

So I manually changed the buffer size in the config file

Fullscreen configuration.txt Download

# General config
CONFIG_TEST_RANDOM_GENERATOR=y

# Networking
CONFIG_NETWORKING=y
CONFIG_NET_SOCKETS_OFFLOAD=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_POSIX_NAMES=y

# LTE link control
CONFIG_LTE_LINK_CONTROL=y
CONFIG_LTE_AUTO_INIT_AND_CONNECT=n

# BSD library
CONFIG_BSD_LIBRARY=y

# AT Host
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_AT_HOST_LIBRARY=y

# MQTT
CONFIG_MQTT_LIB=y
CONFIG_MQTT_LIB_TLS=n

# Appliaction
CONFIG_MQTT_PUB_TOPIC="publish"
CONFIG_MQTT_SUB_TOPIC="subscribe"
CONFIG_MQTT_CLIENT_ID="MyCDevice"
CONFIG_MQTT_BROKER_HOSTNAME="MaxusHub.azure-devices.net"
CONFIG_MQTT_BROKER_PORT=11105

# Main thread
CONFIG_MAIN_THREAD_PRIORITY=7
CONFIG_MAIN_STACK_SIZE=4096

CONFIG_HEAP_MEM_POOL_SIZE=1024

# Disable native network stack to save some memory
CONFIG_NET_IPV4=n
CONFIG_NET_IPV6=n
CONFIG_NET_UDP=n
CONFIG_NET_TCP=n

#added Configuring of buffer sizes?
CONFIG_MQTT_MESSAGE_BUFFER_SIZE = 128
CONFIG_MQTT_PAYLOAD_BUFFER_SIZE = 128

And once I try to build it, it gives me an out of tree board error

My main question is, would I be able to resolve the -12 mqtt_connect error by adjusting the buffer size? And if so, how would I go about doing that if not in the proj.conf file.

Any help is appreciated, thank you

Octavio

EDIT: I should add, I tried running SES as administrator and that didn't seem to help.

[Sigurd]

Hi,

There is some syntax error in your config file, you should remove the space around the = sign, i.e. so it looks like this instead:

CONFIG_MQTT_MESSAGE_BUFFER_SIZE=128
CONFIG_MQTT_PAYLOAD_BUFFER_SIZE=128

octvargas said:

would I be able to resolve the -12 mqtt_connect error by adjusting the buffer size?

It's worth trying, but if you are hitting the ENOMEM shown in the screenshot you attached, then it seems like you are getting the ENOMEM because the buffers are NULL.

Did you call client_init() before calling mqtt_connect() ?

	client_init(&client);
	err = mqtt_connect(&client);

And are the buffers defined like this ?

/* Buffers for MQTT client. */
static u8_t rx_buffer[CONFIG_MQTT_MESSAGE_BUFFER_SIZE];
static u8_t tx_buffer[CONFIG_MQTT_MESSAGE_BUFFER_SIZE];
static u8_t payload_buf[CONFIG_MQTT_PAYLOAD_BUFFER_SIZE];

[octvargas]

hi sigurd,

yeah I set the buffer config back to normal and after some debugging of the code I realized that I'm getting -12 not because of the buffer size. after some more debugging yesterday I seem to be hitting an error in one of the other header files. it a ..not enough core error? i'm not sureI seem to be hitting -61 before getting to -12 for the error  codes

[Sigurd]

If you get -61(ECONNREFUSED), it could be that the username or password is not configured correctly. Take a look at this post.

[octvargas]

yeah, I have seen that post before. But since I'm trying to get the program to link to azure iothub I'm also going off this post

https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-mqtt-support#additional-considerations

specifically "using mqtt protocol as a device"

[octvargas]

stepping through the code w/ the Link Monitor On I THINK I've traced my problem to an error in a function

connect_request_encode in the mqtt_internal.h file

However, I can't seem to find the mqtt_internal.c file to further track it down. is there a reason why that file wouldn't be included?

[Sigurd]

connect_request_encode() function can be found in mqtt_encoder.c

[octvargas]

Thank you,

after more debugging I've traced my initial error -12 to 

static int pack_utf8_str in the mqtt_encoder.c

would that be a problem w/ my buffer size?

[Sigurd]

Looks like you need to increase the buffer size. Try to set CONFIG_MQTT_MESSAGE_BUFFER_SIZE to 512

[octvargas]

and I would do this in the proj.conf file, correct?

CONFIG_MQTT_MESSAGE_BUFFER_SIZE=512
CONFIG_MQTT_PAYLOAD_BUFFER_SIZE=512

like that?