How does a USB keyboard work?

Ben Eater · 3.8M views · 2021-06-05 · 34:15

Open on YouTube ↗

If playback is restricted in your region, try opening the original video. Use Mark watched to add it to your marked videos.

Overview

Ben Eater explains how a USB keyboard communicates, covering the electrical interface, bit and packet encoding, packet contents, and a comparison with PS/2.

On Hacker News

HN commenters recommend it as a clear, comprehensive explanation of USB signaling and keyboard polling.

Recommended by 7 HN people across 6 months · HN mentions 2021–2025

Topics

Electronics & circuit design Embedded systems & DIY electronics Computer architecture & CPUs

What people said

ericbarrett · 2024-11 · Strong recommendation
Among other things, the USB host polls the keyboard at a fixed rate. Fantastic breakdown if you have 30 minutes: [VIDEO]
Read the original HN comment ↗

jordibc · 2022-03 · Strong recommendation
About the USB keyboard, that may be true only for the cheapest keyboard you could find, but basically not applicable anymore nowadays. Rather than giving you the details, let me link to this video, which is awesome at explaining it and much more -- the USB vs PS/2 part starts here: [VIDEO]
Read the original HN comment ↗

lozenge · 2022-09 · Recommendation
Ben Eater has some videos showing the USB protocol on an oscilloscope. [VIDEO] [LINK] And some videos on using chips and breadboards to meet protocols- [LINK] And a digital protocol too- [LINK]
Read the original HN comment ↗

Sources

Video by Ben Eater, played through YouTube.

HN Library · Source license

Data and selection notes

HN summaries and labels may contain AI errors. HN dates refer to discussions, not video publication.

HN Library: HackerTube export (2026-10-31) and open-index/hacker-news. Upstream summaries and classifications may contain AI errors.

Views, duration and playback status refresh separately from the published catalog. When an update fails, existing data remains visible.

Selection checks

SaaS & AI candidates: Topic keywords do not match
Editor-approved picks: Editorial review is required

Rule matches identify candidates. They do not guarantee video quality or financial results.

About the library and its sources