simple_serial - Serial Port Communication for Eiffel

Overview

simple_serial provides serial port (COM port) communication for Eiffel applications. It uses inline C externals for Win32 API calls following the Eric Bezault pattern. Supports configurable baud rates, parity, stop bits, and flow control with a fluent builder API.

Part of the Simple Eiffel ecosystem.

Quick Start

Installation

Set the environment variable:
```
SIMPLE_EIFFEL=D:\prod
```

Add to your ECF file:

<library name="simple_serial" location="$SIMPLE_EIFFEL/simple_serial/simple_serial.ecf"/>

Basic Usage

local
    serial: SIMPLE_SERIAL
    port: detachable SERIAL_PORT
do
    create serial
    port := serial.open_port ("COM3")

    if attached port as p then
        if p.write_string ("Hello device!") then
            print (p.read_string (100))
        end
        p.close
    end
end

Classes

Class	Description
`SIMPLE_SERIAL`	Main facade with factory methods for opening ports
`SERIAL_PORT`	Port handle for read/write operations
`SERIAL_PORT_CONFIG`	Configuration (baud rate, parity, stop bits, flow control)
`SERIAL_PORT_ENUMERATOR`	Discover available COM ports

Configuration

Use the fluent builder pattern to configure serial port settings:

local
    config: SERIAL_PORT_CONFIG
do
    create config.make_default
    config := config
        .set_baud_rate (115200)
        .set_data_bits (8)
        .set_parity ({SERIAL_PORT_CONFIG}.parity_none)
        .set_stop_bits ({SERIAL_PORT_CONFIG}.stop_bits_one)
        .set_flow_control ({SERIAL_PORT_CONFIG}.flow_control_hardware)

    port := serial.open_port_with_config ("COM3", config)
end

Configuration Constants

Category	Constants
Parity	`parity_none`, `parity_odd`, `parity_even`, `parity_mark`, `parity_space`
Stop Bits	`stop_bits_one`, `stop_bits_one_and_half`, `stop_bits_two`
Flow Control	`flow_control_none`, `flow_control_hardware`, `flow_control_software`

API Reference

SERIAL_PORT

Feature	Description
`open: BOOLEAN`	Open with default config (9600-8-N-1)
`open_with_config (config): BOOLEAN`	Open with custom configuration
`close`	Close the port
`write_string (s): BOOLEAN`	Write string, returns success
`write_bytes (bytes): BOOLEAN`	Write raw bytes, returns success
`read_string (max): STRING_8`	Read up to max characters
`read_bytes (max): ARRAY [NATURAL_8]`	Read up to max bytes
`read_line: STRING_8`	Read until newline or timeout
`is_open: BOOLEAN`	Is port currently open?
`last_error: detachable STRING_32`	Last error message

Port Discovery

-- List all available ports
across serial.available_ports as p loop
    print (p + "%N")
end

-- Find Bluetooth devices (paired via OS)
across serial.bluetooth_ports as p loop
    print ("Bluetooth: " + p + "%N")
end

-- Find USB serial adapters
across serial.usb_ports as p loop
    print ("USB: " + p + "%N")
end

Features

Cross-Platform API

Windows implementation complete, Linux/macOS planned.

Fluent Configuration

Chain configuration calls for clean, readable code.

Port Enumeration

Discover available COM ports, filter by Bluetooth/USB.

Design by Contract

Full preconditions, postconditions, and invariants.