source code of protocols

[latifa]

Hello everyone,

I am currently working on a project to develop drivers for STM32F4 microcontrollers, based on Reference Manual RM0090 (without HAL, only CMSIS and register access).

The goal of the project is to design reusable low-level drivers for the following peripherals:

• USART / UART

• SPI

• I2C

I am now in the code implementation phase.

I would like the community's help with the following:

1. Examples of source code or references (preferably bare-metal / register level) for:

   • SPI : transmission et réception

   • I2C : master transmit / master receive

   • UART : transmission et réception

2. Recommendations on API structure and function naming, for example:

   • SPI_Init(), SPI_Transmit(), SPI_Receive()

   • I2C_MasterTransmit(), I2C_MasterReceive()

   • USART_Transmit(), USART_Receive()

Any help, code snippets, links to reference implementations, or feedback would be greatly appreciated.

Thank you in advance for your help.

Best regards,

*This post has been translated from French to comply with the ST Community guidelines.

[TDK]

There are lots of LL library examples. Maybe those will give you some inspiration. HAL library is also perfectly usable. You can re-implement as register access if desired.

[Ozone]

The "legacy" SPL is still available for download at ST for the F4 devices, which provides a relatively thin abstraction layer.
Although it contains some bloated code as well that tries to be too generic.

I often take SPL code as a template in my projects, and strip it down to the functionality required.
Which usually means copying the "register access" code from the SPL functions, and adapting it.