Who runs this site
TechThings.work is a personal, non-commercial project written and maintained by Callum Haywood. It is not operated by, affiliated with or endorsed by any employer, vendor or standards body mentioned anywhere on the site.
References to companies, products and standards — Wi-Fi, Bluetooth, USB, Visa, Mastercard and the rest — are made for the purpose of explaining how they work. All trade marks remain the property of their owners, and their use here does not imply any connection or approval.
What this site is, and what it is not
The guides are educational explanations aimed at a general reader. They are deliberately simplified: details are left out, edge cases are skipped, and analogies are used where a complete treatment would obscure the point.
That makes them useful for understanding, and unsuitable as a specification. In particular, nothing here is:
- professional, legal, financial or security advice;
- a substitute for a manufacturer’s documentation or a published standard;
- a design reference for anything safety-critical, regulated or load-bearing;
- a guarantee that a described behaviour matches any particular product.
Use it to understand, not to certify If a decision carries real consequences — an installation, a purchase, a compliance obligation, a security control — check the actual standard or the manufacturer’s documentation. This site is a starting point, not an authority.
Accuracy
Considerable care goes into getting this material right, and corrections are welcome. Even so, the content is provided as it is, without any warranty that it is accurate, complete or current.
Technology moves. Standards are revised, products change behaviour, and a statement that was true when written may quietly stop being true. Pages carry a date; treat anything time-sensitive with that in mind.
Copyright and reuse
The text, diagrams and code on this site are © Callum Haywood unless stated otherwise. You are welcome to do the ordinary, reasonable things with it.
| You may, without asking | Please ask first |
|---|---|
| Read, print and save pages for your own use | Republishing a guide in full |
| Share a link, anywhere, freely | Reproducing the diagrams elsewhere |
| Quote a short passage with a credit and a link | Any commercial or paid-for use |
| Use it to teach, and point students at it | Translations or derivative versions |
| Cite it in your own writing | Training a model on the full text |
Where a credit is appropriate, “TechThings.work” with a link to the page is plenty. Permission for anything in the right-hand column is usually given readily — the request simply makes it possible to keep track.
Using the site
There is no account to create, nothing to buy and nothing to submit, so the list of things not to do is short. Please do not attempt to disrupt the site or the server it runs on, to gain access to anything not intended to be public, or to scrape it at a volume that degrades it for other people.
Normal reading, linking, printing and ordinary crawling by search engines are all expected and entirely welcome.
Links to other sites
Some pages link to external sites — standards bodies, manufacturers, reference material. Those sites are not under my control. A link is not an endorsement, and I am not responsible for their content, their accuracy or their privacy practices.
Availability
This is a personal project on ordinary hosting. It may be unavailable at times, for maintenance or for reasons entirely outside my control, and pages may be changed, moved or withdrawn without notice. No uptime is promised.
Liability
To the fullest extent the law allows, I am not liable for any loss or damage arising from your use of this site or from reliance on anything published here — including loss of profit, loss of data, or business interruption, whether direct or indirect.
Nothing in these terms excludes or limits liability for death or personal injury caused by negligence, for fraud or fraudulent misrepresentation, or for anything else that cannot lawfully be excluded. If you are a consumer, your statutory rights are unaffected.
Changes to these terms
These terms may be updated from time to time. The current version always applies, and the date at the top of this page tells you when it last changed. Continuing to use the site after a change means accepting the revised terms.
Governing law
These terms are governed by the law of England and Wales, and the courts of England and Wales have exclusive jurisdiction over any dispute arising from them.
Contact
For permission requests, corrections or anything else about these terms, get in touch via callumhaywood.com.
See also the privacy notice, which covers what happens to data when you visit.