The developer's resource for computer interfacing, especially USB, serial (COM) ports, mass storage, and embedded networking. (Formerly


USB Complete: The Developer's Guide, Fifth Edition is available now!

If you have a question about USB, serial port, embedded Ethernet, parallel port, or other interface-related topics, please post it on my PORTS web forum.

I've updated my Visual C# .NET application for accessing WinUSB devices and the companion PIC firmware.

I've updated my Visual C# .NET application for accessing generic HID-class USB devices using asynchronous reads and writes with Filestreams.

I'm honored to be one of the featured interviewees in Circuit Cellar's 25th anniversary issue.

My article Debugging USB Firmware is online at Circuit Cellar.

This site was selected as an EEWeb Engineering Site of the Day. Read EEWeb's interview with me.


Select a topic or book for more information.


USB CompleteUSB Central. For developers of peripherals and software for the Universal Serial Bus.

USB Complete: The Developer's Guide. Fifth Edition.

USB Embedded Hosts

USB Embedded HostsUSB OTG and Embedded Hosts. For developers of embedded systems that access USB devices.

USB Embedded Hosts: The Developer's Guide.

Serial Ports

Serial Port CompleteSerial Port Central. For developers using serial links and networks, especially for monitoring and control applications.

Serial Port Complete: COM Ports, USB Virtual COM Ports, and Ports for Embedded Systems. Second Edition.

Mass Storage

USB Mass StorageMass Storage Page. For developers of USB mass-storage devices, devices that interface to flash-memory cards (MultiMediaCard, SD Card, CompactFlash), and embedded USB mass-storage hosts.

USB Mass Storage: Designing and Programming Devices and Embedded Hosts.

Embedded Ethernet and Internet

Embedded Ethernet and Internet CompleteEmbedded Ethernet and Internet Central. For developers of devices that communicate on Ethernet networks or on the Internet.

Embedded Ethernet and Internet Complete: Designing and Programming Small Devices for Networking.

Parallel Port

Parallel Port CompleteParallel Port Central. For developers who are using the PC's parallel port, including ECP, EPP, bidirectional, and IEEE-1284 modes (and other I/O ports too). Includes inpout DLLs and other tools for port I/O.

Parallel Port Complete: Programming, Interfacing, and Using the PC's Parallel Printer Port.


The Microcontroller Idea Book8052-Basic Microcontrollers. For users of the 8052-Basic and similar 8051-family microcontrollers

The Microcontroller Idea Book. Circuits, Programs, & Applications featuring the 8052-BASIC Microcontroller.

Printed Circuit Boards

Making Printed Circuit BoardsMaking Printed Circuit Boards. Links to information and tools for making PC boards.

Making Printed Circuit Boards: with projects and experiments.