Hacker News Reader

Comment by PoachedSausage | Hacker News Reader

> Every sensor is a temperature sensor. Some sensors measure other things as well.

Some components can become sensors under the right conditions. Example: Components becoming microphonic.

At high enough frequencies digital design becomes analogue design.

That is how I was convinced to take a microwave engineering course. I was an EE undergrad, and had just struggled through the electrodynamics course. My professor asked me to take his microwave engineering course the following semester. I said I was not planning on it, since I had enough trouble getting through the prerequisite and I had no plans to become a microwave engineer. He asked me the following questions-

Professor: "How fast is your computer at home?" - Me:"2.8GHz.", Professor: "OK, and what is considered the start of the microwave band?" - Me: "1 GHz" Professor: "So, I will see you next semester?"

It turned out to be a great course, we built antennas, resonators, did simulations and compared to physical results, talked about a lot of different situations. In my career as a software engineer I have made great use of that knowledge by being able to better understand the issues that my EE counterparts are working on.

> At high enough frequencies digital design becomes analogue design.

I've heard this stated as "the difference between digital engineers and analog engineers is that the analog engineers KNOW when they're designing an antenna".

> "the difference between digital engineers and analog engineers is that the analog engineers KNOW when they're designing an antenna".

Hahaha this is a beautiful quote! I didn't believe this was a real concern until I ran into it in the real world.

I read a great how-to once where someone described a device which blinks in the dark - and only in the dark - that uses the LED itself as light sensor.

That is pure evil.

At work we replace an obsolete diode in part of a circuit in front of a high gain amplifier. The new equivalent diode came in a glass package unlike the old one. It caused a bit of head scratching to figure out why the circuit wasn't behaving as it should and also appeared to be acting as a human proximity detector.

At high enough frequencies digital design becomes analogue design.

It's a great time to be a digital engineer. Projects like the PocketVNA and the NanoVNA-V2 make it feasible for you to do professional grade S parameter measurements of digital traces at home.

Pair them with QucsStudio, and you have a near professional grade high speed simulation package available for less than $500. So cool.

And, speaking of Rules of Thumb - Embedded Artistry's page calls out Eric Bogatin's Signal Integrity Rules of Thumb as well, which is a fantastic series of blog posts on high speed digital design and signal integrity. Worth a read if high speed digital design is your thing.

Had a GPS that started jabbering crap when it got cold.... showed up as system dying because it was being flooded with events, ie. Some other task died because it wasn't getting enough cpu time.

Very true. Only depends if its thermal behavior matches your application's needs.

So true!

Reply on news.ycombinator.com