SLM HTTP client hangs with large payload

[Anthony Ambuehl]

I recently switched  from 1.5.1 to 1.6.1 and I'm now finding the SLM is misbehaving.

When I try to send a large payload such as 933 bytes of data, I find the CTS signal goes low after 274 bytes of data were sent.  (There is some buffering in my mcu so probably less received at SLM uart) 

It seems like the SLM data mode uses a ring buffer that is only 256 lines and the datamode cannot handle payloads longer than this.  

Please confirm large payloads work in 1.6.1.  

Also any advice on how to get debug logging from SLM_AT_HOST and SLM_AT_HTTPC ?  I'm running from SES with stock SLM example...

[Håkon Alseth]

Hi,

 

I find the CTS signal goes low after 274 bytes of data were sent.  (There is some buffering in my mcu so probably less received at SLM uart) 

Just to clarify, from which side is it set low?

 

Also any advice on how to get debug logging from SLM_AT_HOST and SLM_AT_HTTPC ?  I'm running from SES with stock SLM example...

If you set the log level to debug (4) here:

https://github.com/nrfconnect/sdk-nrf/blob/v1.6.1/applications/serial_lte_modem/prj.conf#L8

 

Then it should print out debug logs over RTT. Could you try this and attach the log showing the issue?

 

Kind regards,

Håkon

[Anthony Ambuehl]

I tried enabling logs by changing prj.cnf line 8 to:

CONFIG_LOG_DEFAULT_LEVEL=4

I ran cmake and the rebuilt merged.hex (F7)

The only log lines are produced by the bootloader and then it goes silent. 

Is it possible that logging is disabled completely somehow or that the application has a different location for the RTT block vs the bootloader? 

Perhaps there are 2 RTT blocks one in secure  zone and one non-secure?

Is there a way to build and run where I will get debug logs for the application?