How to use STM32 UART interface in different modes?

How to use STM32 UART interface in different modes?

This tutorial shows how to use the STM32 UART interface in different modes using the HAL libraries. We will show how to use direct mode, interrupt-based mode and DMA-controlled mode and will use a logic analyzer to compare the precise timings of various events. Before you begin, install VisualGDB 5.2 or later.

How to enable or disable USART in STM32?

Enable the USART by writing the UE bit in USART_CR1 register to 1. Program the M bit in USART_CR1 to define the word length. Program the number of stop bits in USART_CR2. Select DMA to enable (DMAT) in USART_CR3 if Multi buffer Communication is to take place.

What does STM32 automatic baud rate detection 2.1 do?

STM32 Series microcontrollers are Arm®(a)-based devices. Hardware automatic baud rate detection 2.1 Feature overview Automatic baud rate detection (ABR) allows the receiving device to accept data from a variety of transmitting devices operating at different speeds without needing to establish data rates in advance.

Where can I find UART module in my microcontroller?

UART is sold/shipped as a standalone integrated circuit (IC) or as an internal module within microcontrollers. In this tutorial, we’re actually concerned with the internal UART module within STM32 Microcontrollers.

How to implement Hal UART in DMA mode?

The appropriate DMA instance, UART-DMA channel, GPIO and alternate function settings should be changed according to the STM32 microcontroller in use. Your problem looks similar to DMA UART with HAL remain busy bug . You should enable HAL_UART_IRQHandler () i.e. inside “main.c” (or wherever you initialize your hardware) add:

Can a STM32 microcontroller use a DMA channel?

The example was written for an STM32F4 Discovery board (STM32F407VG). The appropriate DMA instance, UART-DMA channel, GPIO and alternate function settings should be changed according to the STM32 microcontroller in use. Your problem looks similar to DMA UART with HAL remain busy bug .

How to implement UART in DMA mode in sm32cubeide?

To achieve this in SM32CubeIDE you need to remove the tick for the option Uses FreeRTOS functions in the NVIC configuration and then set the priority for the DMA und UART interrupts accordingly: For me, I was getting an transmit error when using DMA.

What does Hal stand for in STM32 UART?

HAL stands for High Abstraction Layer and as the name implies, these libraries handle the entire bit-wise operations and the user only has to pass the right data to the functions. When we select USART in CubeMX, it will add the corresponding HAL library to our projects and we can directly call those function from our code.

Do you have to call Hal _ UART _ Transmit every time?

Although calling HAL_UART_Transmit () for every transmission is simple, it has one major disadvanrage. While the transmission is active, the program cannot do anything else and has to wait for it to complete. We will now use the interrupt-based transmission to free up some of the CPU cycles.

How are STM32 microcontrollers used in embedded systems?

STM32 microcontrollers are among the most widely adopted microcontrollers in the domain of embedded systems. They are power-efficient and have a small package size. They come on a variety of form factors and are very well documented. In addition to this, they support a wide variety of peripherals like I2C, SPI and UART in a single module.

How is the Hal UART Transmit function active?

Enable the connected signals in Analyzer2go to begin watching them. See how the HAL_UART_Transmit () function (red) is active during the entire transmission (blue):

How to receive serial data with stm32-dma?

Using interrupt signals is a convenient way to achieve serial UART data reception. The CPU initializes the UART receive hardware so that it fires an interrupt signal whenever a new byte of data is received. And in the ISR code, we save the received data in a buffer for further processing.

How is UART data reception handled in ISR?

The CPU initializes the UART receive hardware so that it fires an interrupt signal whenever a new byte of data is received. And in the ISR code, we save the received data in a buffer for further processing. This way of handling the UART data reception is a non-blocking way.