USART Peripheral Abstractions

[dchansen06]

This is the parent issue for the initial USART peripherals in the monorepo. Please keep this up to date.

[GabeMillikan]

Here are some notes about USART for tomorrow:

USART stands for "Universal Synchronous and Asynchronous Receiver-Transmitter", is a module capable of both synchronous and async serial communication. UART refers to the asynchronous capabilities of these modules.

USART typically involves three wires. One for TX, one for RX, and one for the clock.

The clock signal is what "synchronizes" the communicators, so when that signal is absent or ignored that is called the "asynchronous" mode. When in asynchronous mode, start & stop signals need to be included in the serial line to indicate packet edges. This happens automatically within HAL.

There exists documentation for USART on STM32

You can transmit data over uart via:

UART_HandleTypeDef huart1; // it is not clear to me why we need not initialize this

uint8_t tx_buff[]={0,1,2,3,4,5,6,7,8,9};
HAL_UART_Transmit(&huart1, tx_buff, 10, 1000);

And you can receive via:

uint8_t rx_buff[10];
if(HAL_UART_Receive(&huart1, rx_buff, 10, 1000) == HAL_OK) {}