SPWF01 can't find host IP of AWS IoT server

[N S]

Posted on February 09, 2017 at 10:32

Hello,

we are making MQTT client application that should connect to Amazon AWS server. But after my application sends:

AT+S.SOCKON=XXXXXXXXXXXXXX.iot.eu-west-1.amazonaws.com,8883,s,ind<CR>

I got an error:

ERROR: Failed to resolve name<CR><LF>

Temporary solution was to find real IP of server using whois in my console and put is instead of server address. Now i can connect but i want to use real server address in application if possible.

 

Moreover, I'm sure that DNS address is correct because we are using time-d.nist.gov service to get current time/date without a problem.

Maybe the address string is too long for module? (We are using latest firmware for SPWF01 that is available for download v3.5)

 

73HelloHan MQTTa2emqd0m2h8v13

[Gerardo GALLUCCI]

Posted on March 11, 2017 at 14:56

Ciao Nebojsa,

I assume problem with connection is solved by FW update >3.5. Good news.

About SPWF04S, yes, it's pin to pin compatible (there are more pins, but can be left floating if not used). AT commands are 90% aligned (e.g., there is no command/data mode switch). Samples are already available (ask for them to your distributor, or direct ST office).

About certificates:

- SPWF01S can store 4 certificates (2Kb each, aligned to STM32F1 flash page size): CA, client cert, client key, and server's domain name

- SPWF04S can store again 4 certificates (4Kb each, aligned to STM32F4 smallest sector size): CA, client cert, client key, and optional subject key (depending on PEM or DER usage). Moreover, it can load certificates directly from file system

Best regards

jerry

[N S]

Posted on April 19, 2017 at 13:45

Hi Gerardo,

i ended up with this setup:

CA root: bytes bytes

cert: 2208 bytes

key 310 bytes

Can you edit firmware file to accomodate a little more place for certificate file, for example from 2kb to 3kb, and for shrink client key size from 2kb to 1kb. That would be pretty much ok for our setup and it will use same amount of space inside cpu flash memory.

109

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[Gerardo GALLUCCI]

Posted on April 19, 2017 at 23:54

Hi,

hard to implement (higher flash, higher RAM...). Usually ECC certificates are smaller. Can you use ECC?

[N S]

Posted on April 20, 2017 at 00:32

It is ECC. I need a little more than 2kb (2048bytes). Actually 2208 bytes. That certificate is sent only once on first connect to AWS. After that i can continue smaller certificate which is inside current limits.

451

[Gerardo GALLUCCI]

Posted on April 20, 2017 at 09:53

Got it. I'll push your request to dev team.

Did you evaluate SPWF04 too?