Flow control required for uBlox SARA-R4 cellular comm interface?


I got the windows cellular interface demo to work with a dev board equipped with the SARA-R410M-02B-01. The windows demo works without using UART flow control.

Now I’m trying to get it to run on my microcontroller and I noticed the STM32 L475 comm interface uses UART flow control. In the datasheet of the SARA-R4 series it is mentioned that the SARA-R410M-02B-00 does not support flow control. The last two digits of my modem are “01” instead of “00” and the meaning of these are not mentioned in the datasheet, so I’m not sure if I can use the available comm layer for the L475.

Anyone here with some experience with this?

I’m also interested in the reason for choosing flow control instead of DMA.

The STM32L475 UARTs do support hardware flow control, but you can disable that feature. So the 'L475 will be able to support communications with the SARA module no matter what it needs.

You might be able to ask uBlox about the “01” vs “00” in your part number.

It turns out the SARA-R410M-02B-01 does support flow control. I hooked the UART up with all flow control lines and managed to get the comm interface and cellular interface to work.

Thank you for taking time to report back.