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SARTHAK KELAPURE
SARTHAK KELAPURE
Associate III
December 16, 2017
Solved

Problem with UART and LL drivers

  • December 16, 2017
  • 3 replies
  • 1034 views
Posted on December 16, 2017 at 05:53

Hello everyone, this is a problem regarding my DISCO-L072CZ-LRWAN kit which I am using for a project of mine.

I am using the LRWAN expansion kit for LoRa functionality while I am also trying to add up a UART as UART1 on Pin 9/10. While using this UART, I am trying to use the HAL drivers especially HAL_UART_Receive function which receives N number of character and has a timeout given by the user which I am giving as 0x00FF. Internally this function takes sysTick using Get_HAL_Tick() but as the LoRa function has initialized all LL drivers, the getting systick function from HAL does not work. Which means that there will be no timeout and I have to specify the number of characters to be received, which is bizarre.

I hope you understood my problem. Please try and help with solution or any other alternative.

If you have any solution for UART which solves this problem please reply.

#b-l072z-lrwan1 #b-l072z-lrwan1
This topic has been closed for replies.
Best answer by Tesla DeLorean
Posted on December 16, 2017 at 17:39

The LRWAN implementation uses the RTC over SysTick, but it is possible to implement/enable SysTick if you need/want to.

Unless you've got a bunch of experience I wouldn't try to mix HAL and LL stuff up to much. I would strongly recommend reading the Reference Manuals so you know how the underlying hardware works as this will provide a lot of clarity about what the software needs to do.

The LRWAN/VCOM implementation is a bit of a mess, there is a lot of blocking code compounded by the way the CM0+ NVIC works. I ended up reworking most of that code to use the status and data registers more directly, and providing some more effective FIFO buffering via the IRQ Handlers.

3 replies

S.Ma
S.Ma
Principal
December 16, 2017
Posted on December 16, 2017 at 07:18

Either go to debug mode to figure out how to cascade the Systick interrupt to all functions needing them, or use a simple unused STM32 Timer to build a programmable timeout event that you use in your main loop to abort UART (ie: Make your own timeout).

Andrew Neil
Andrew Neil
Super User
December 16, 2017
Posted on December 16, 2017 at 13:35

SARTHAK KELAPURE wrote:

I am trying to use the HAL drivers especially HAL_UART_Receive function

But your thread title says LL Drivers - so which is it?

Do you actually need the timeout?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
Tesla DeLorean
Tesla DeLoreanAnswer
Guru
December 16, 2017
Posted on December 16, 2017 at 17:39

The LRWAN implementation uses the RTC over SysTick, but it is possible to implement/enable SysTick if you need/want to.

Unless you've got a bunch of experience I wouldn't try to mix HAL and LL stuff up to much. I would strongly recommend reading the Reference Manuals so you know how the underlying hardware works as this will provide a lot of clarity about what the software needs to do.

The LRWAN/VCOM implementation is a bit of a mess, there is a lot of blocking code compounded by the way the CM0+ NVIC works. I ended up reworking most of that code to use the status and data registers more directly, and providing some more effective FIFO buffering via the IRQ Handlers.

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SARTHAK KELAPURE
SARTHAK KELAPUREAuthor
Associate III
December 19, 2017
Posted on December 19, 2017 at 06:45

Well thank you. I ended up mixing the HAL and LL drivers and it works as of now. Even I am going to remake vcom.c again. Thank you.

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