The USART (Universal Synchronous and Asynchronous serial Receiver and Transmitter) is a crucial peripheral in the ATmega328 microcontroller, used for serial communication. It supports both asynchronous and synchronous communication modes. This allows the microcontroller to communicate with other devices (such as sensors, computers, or other microcontrollers) via UART or SPI, depending on the configuration.
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Here you'll find a collection of useful links and videos related to the topic of AVR microcontrollers.
USART0 Overview
├── Documentation
│ ├─ [USART0 Modes]
│ │ ├─ Registers — UCSR0C (UMSEL0 bits)
│ │ ├─ Modes — Asynchronous, Synchronous
│ │ └─ Examples — Switching modes and timing differences
│ │
│ ├─ [USART0 Baud Rate]
│ │ ├─ Registers — UBRR0H, UBRR0L
│ │ ├─ Concept — Baud rate calculation formula
│ │ └─ Effects — Impact on transmission speed and error rate
│ │
│ ├─ [USART0 Interrupts]
│ │ ├─ Registers — UCSR0B (RXCIE0, TXCIE0, UDRIE0), UCSR0A flags
│ │ ├─ Sources — RX Complete, TX Complete, Data Register Empty
│ │ └─ Control — Enable, flag handling, and ISR examples
│ │
│ ├─ [USART0 Data Registers]
│ │ ├─ UDR0 — USART Data Register (Read/Write)
│ │ ├─ Transmission — Data load and send
│ │ └─ Reception — Data read and buffering
│ │
│ └─ [USART0 Error Handling]
│ ├─ Registers — UCSR0A (FE0, DOR0, UPE0)
│ ├─ Errors — Frame Error, Data Overrun, Parity Error
│ └─ Handling — Error detection and safe recovery
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├── [API_Reference]
│ ├─ File — usart.h / usart.c
│ ├─ Functions — Init, Write, Puts, getChar, Flush
│ └─ Purpose — High-level USART communication interface
│
└── Registers
├─ [UCSR0A] — Status flags: Transmission/Reception status & error flags
├─ [UCSR0B] — Control bits: Enable TX/RX, interrupts, and frame size (part 1)
├─ [UCSR0C] — Control bits: Mode select, parity, stop bits, data bits (part 2)
├─ [UBRR0H] — Baud rate register (high byte)
├─ [UBRR0L] — Baud rate register (low byte)
└─ [UDR0] — Data register — Holds incoming or outgoing data
Tip
The resources are detailed in the sections below.
To access any of them, simply click on the corresponding blue link.
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This document provides a detailed explanation of all operating modes for USART0, including Asynchronous, Synchronous modes, along with the register configurations required and timing implications for each.
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This file describes how to set the baud rate for USART0 using UBRR0 register, including the baud rate calculation formula, example configurations for common baud rates, and the effect of clock frequency and U2X0 bit on accuracy.
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Covers all USART0 interrupt sources: Receive Complete, Transmit Complete, and Data Register Empty. Explains how to enable them using UCSR0B, read the related flags in UCSR0A, and properly write interrupt service routines (ISR) for each case.
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Detailed description of UDR0 operation, including how data is buffered for transmission and reception, timing considerations, and tips for avoiding data loss.
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This file explains USART0 error flags in UCSR0A (Frame Error, Data Overrun, and Parity Error), how to detect them, and strategies for robust recovery in high-reliability systems.
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This section provides a detailed description of the functions in the
usart.handusart.cfiles for handling USART communication on the ATmega328 microcontroller. Each function is designed to manage data transmission and reception through USART, as well as configure the necessary registers. -
This repository contains comprehensive resources for AVR microcontrollers, including hardware schematics, software libraries, and educational projects.
AVR, Communication, USART
├── [aKaReZa 66 - AVR, Communication, USART - Part A]
│ ├─ Basics — Features, block diagram, registers.
│ ├─ BaudRate — Calculation and setup.
│ ├─ Data Tx — Sending characters and strings.
│ ├─ Formatting — Escape sequences and frame structure.
│ └─ Simulation — Software vs hardware testing.
│
└── [aKaReZa 67 - AVR, Communication, USART - Part B]
├─ Data Rx — Receiving bytes and using interrupts.
├─ Reliability — Baud errors, flags, circular buffer.
├─ Speed — Double Speed mode usage.
├─ Debugging — Data plotting and USART insights.
└─ Comparison — Simulation vs real-world behavior.
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Learn about USART features and specifications in the ATMega328 microcontroller, including baud rate calculation, registers, single character and string transmission, escape sequences, data frames, and differences in simulation and practical testing. |
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Continuation of USART communication, discussing escape sequences, byte reception, baud rate errors and solutions, double speed mode, data reception with interrupts, circular buffer, USART flags, debugging, and data frames. |
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