uart-echo

UART Echo — Basic Serial Communication

Reads bytes from UART and echoes them back. The simplest way to verify that serial communication works between your board and a host PC.

What it demonstrates

• UART initialization with eos_uart_init()
• Writing strings with eos_uart_write()
• Blocking read with timeout using eos_uart_read()
• Echo loop pattern

Modules used

Module	Header	Functions
HAL	eos/hal.h	eos_hal_init, eos_uart_init, eos_uart_write, eos_uart_read

How to build

cmake -B build -DEOS_PRODUCT=iot
cmake --build build
./build/uart-echo

Expected output

On the serial terminal (115200 baud, 8N1):

=== EoS UART Echo ===
Type characters and they will be echoed back.
Running at 115200 baud, 8N1

Every character you type is immediately echoed back.

Hardware connections

Board	UART TX	UART RX	Notes
nRF52840-DK	P0.06	P0.08	USB-UART via J-Link
STM32 Nucleo	PA2	PA3	UART2, connect USB-UART adapter
Host build	stdout	stdin	Simulated via printf