FaSTTUBe CAN HAL Abstraction Layer

This repository contains an abstraction layer to provide a simplified & unified interface to the STM32 bxCAN and FDCAN peripherals.

Installation

Simply add the repository to your Core/Lib directory. You can also add it as a git submodule:

mkdir -p Core/Lib
cd Core/Lib
git submodule add ssh://git@git.fasttube.de:313/FaSTTUBe/can-halal.git

The library needs to be told what STM family you're using, so make sure one of the following symbols is defined when can-halal.c is compiled or can-halal.h is included:

• STM32F3
• STM32H7

When using the FDCAN peripheral (H7 series), you also need to define FTCAN_NUM_FILTERS (and set it to the value of "Std Filters Nbr" you configured in your .ioc).

If you use VSCode with the stm-32-for-vscode extension, you can add these definitions in the STM32-for-VSCode-config.yaml file, e.g.:

# Compiler definitions. The -D prefix for the compiler will be automatically added.
cDefinitions:
  - STM32H7
  - FTCAN_NUM_FILTERS=32

Usage

1. Include can-halal.h
2. Call ftcan_init() with the appropriate handle
3. Call ftcan_add_filter() with all your filters
4. To transmit messages, call ftcan_transmit()
5. When a message is received, ftcan_msg_received_cb() is called. It has a default empty implementation, which you can simply override.

Enabling CAN in STM32CubeMX

This isn't specific to can-halal, but for completeness sake is included here.

bxCAN (e.g. STM32F3xx)

1. Enable the CAN peripheral
   
2. Setup the bit timings.
   Note: the baud rate depends on your system clock, so make sure that is setup correctly first!
   
3. Make sure the CAN_RX0 interrupt is enabled
   

FDCAN (e.g. STM32H7xx)

1. Enable the CAN peripheral
   
2. Setup the frame format, nominal SJW, filters, and FIFOs. The numbers for filters/FIFOs in the screenshot are examples.
   Note: You need to tell can-halal about the number of filters by defining FTCAN_NUM_FILTERS (see above).
   
3. Setup the bit timings. We only use CAN in classic mode, not FD mode, so we only need to worry about the nominal bit timings
   Note: the baud rate depends on your system clock, so make sure that is setup correctly first!
   
4. Make sure the interrupts are enabled