uBlox Sara-U270 comm interface timing out

I’m trying to integrate a stm32F205 with a Sara U-blocks U270 using the Sara R4 port provided with the cellular interface. I am able to send at commands and receive the response within the iot fifo buffer but the iot interface continues to return busy even after the end of the message has completed and eventually times out.

Hi Adam,

The question is duplicated in this thread.

It could be the comm interface problem.
Detail reasons and patches are provided in previous thread.

We can do the followings to help locating the problem:

  1. Use FreeRTOS windows simulator as a comparison.
  2. Add more debug log to indicate the timeout reason.

A patch to reproduce this problem on windows simulator is also provided to help understanding this problem.

Let’s move the discussion in previous thread.
Please provide more information for discussion.