Overview of the Serial Communication Protocol
In Series

© Lead Image © 3355m, 123RF.com
We explore serial communications, from the electrical specs to protocols and libraries, with an example of serial communication with an Arduino.
The word "serial" in terms of computers might bring several things to mind. In modern times, it might be the universal serial bus (USB). Not too long ago, it might have brought to mind a 9-pin connector on the back of your desktop – or the even bigger 25-pin connector a bit before that. Different, still, the term might bring up memories of modems, printers, or peripherals connected to specialty computers. If you look at early mainframes, the serial port was the main interface to a text terminal and thus the human interface to the computer.
Some of these usages have been superseded by newer or different technologies, but serial is still alive and well. Although not as common on today's computer equipment, serial communication is far from gone, and its availability can provide some interesting possibilities for talking to unique hardware.
Basic Principles
In the simplest sense, an electric circuit used for communication just uses a completed circuit to represent a 1 and a broken circuit to represent a 0. See the "Telegraphy" sidebar for how this worked in real life for years. The limitation of a simple telegraphy circuit is that for each signal you want to send, you need a dedicated wire.
[...]
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

News
-
TuxCare Announces Support for AlmaLinux 9.2
Thanks to TuxCare, AlmaLinux 9.2 (and soon version 9.6) now enjoys years of ongoing patching and compliance.
-
Go-Based Botnet Attacking IoT Devices
Using an SSH credential brute-force attack, the Go-based PumaBot is exploiting IoT devices everywhere.
-
Plasma 6.5 Promises Better Memory Optimization
With the stable Plasma 6.4 on the horizon, KDE has a few new tricks up its sleeve for Plasma 6.5.
-
KaOS 2025.05 Officially Qt5 Free
If you're a fan of independent Linux distributions, the team behind KaOS is proud to announce the latest iteration that includes kernel 6.14 and KDE's Plasma 6.3.5.
-
Linux Kernel 6.15 Now Available
The latest Linux kernel is now available with several new features/improvements and the usual bug fixes.
-
Microsoft Makes Surprising WSL Announcement
In a move that might surprise some users, Microsoft has made Windows Subsystem for Linux open source.
-
Red Hat Releases RHEL 10 Early
Red Hat quietly rolled out the official release of RHEL 10.0 a bit early.
-
openSUSE Joins End of 10
openSUSE has decided to not only join the End of 10 movement but it also will no longer support the Deepin Desktop Environment.
-
New Version of Flatpak Released
Flatpak 1.16.1 is now available as the latest, stable version with various improvements.
-
IBM Announces Powerhouse Linux Server
IBM has unleashed a seriously powerful Linux server with the LinuxONE Emperor 5.