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Cool. Literally cool.

I think one of the most interesting things I saw this morning is that the orange LED turns green. Also, his explanation is helpful.

Once again... cool

This is absolutely worth reading, and as cool as it sounds!

But pouring liquid nitrogen into a container on the floor next to bare feet...

Pouring liquid nitrogen on your hand and letting it roll off is actually pretty fun (and safe). Just don't let it sit there..

https://en.wikipedia.org/wiki/Leidenfrost_effect

you can let it sit there too LN is mostly safe, dry ice can be a much bigger pain since there is solid to solid contact but even it isn't that bad.

You have quite a large thermal mass a bit of LN won't do that much damage to you, you can dip your hand into LN and keep it there for quite a while :)

You can also wet your hand and dip your fingers into sufficiently hot lead, and again, the leidenfrost effect will protect you (as long as you don't keep your fingers in there for too long).
> hot lead

To me at least, this sounds terrifying compared to the liquid nitrogen.

I have strong doubts about that actually the case, I've seen what happens when water drips into molten metal (things go boom) and even if that wasn't the case the steam would be super heated which is enough to burn your hand to crisp.
https://www.youtube.com/watch?v=yTOCAd2QhGg Mythbusters have tested it themselves and confirmed that it works. The molten lead does have to be at a specific temperature (Too cold, and the steam isn't enough to protect your fingers and slow down the evaporation. Too hot, and the water evaporates pretty much instantly too.)
... and don't wear a ring or wristwatch. Been there.
As long as it flows it's relatively safe. Just step away if you spill some. Bad would be if you would be wearing shoes and accidentally spilled some into the shoe, where it can't flow off.
When I was in high school/college, I had horrid acne. It looked like every pore on my face was plugged, and infected. My father was in a union, so we had great medical insurance. So I went to the dermatologist. We first tried benzoyl peroxide. We then tried topical erythromycin. We then tried oral etryhromycin. The Doctor cured about 80% of the problem. He then used liquid nitrogen on my face. That was the final treatment that cleared up my skin. The only draw back was going in once a week for a spray treatment. I was on foot.

I asked my dad about liquid nitrogen, and he said he could get some at work. The guy at work said you need to keep it in the freezer. My dad brought a bottle home, and once a week he would spray my cheeks, forehead, and chin with liquid nitrogen. We didn't know why it worked, and safety was me telling my father how the detmontologist applied the liquid nitrogen.

My father was a good guy when he was younger. I think he felt sorry for a comment he made to me on a side job, one Saturday.

We were going to a side job, a rat job as my father referred to them. It was a cold, foggy morning. My skin was especially inflamed. My father took a drag off his Carleton light cigarette, squinted his eyes, as said, "Son--your face is starting to deform from those pimples. Well, I felt horrid over the comment. I knew my skin was an impediment to my high school social life, but "my father's aporoval?"

Anyways, that comment got me into a dermatologists office. A three year office visit. I think I had the worst case of acne he encountered. He used to mumble, "You know I have some women who come in for one pimple. I wish they could see this--" We would talk while he cleaned out my pores with an oval tool. A tool designed to pop pimples.

Anywho---don't put liquid nitrogen on the skin. I think me, and my father got lucky. I think the liquid nitrogen killed the top layer of skin? My face looked slightly tan after a treatment, and my skin rubbed off easily the next day. We were lucky we were both scared of the magical mist comming from the tank. The only time I didn't see a cigarette dangling from my father's mouth, was when we were applying the mist to my face. Yea, even then he knew it wasen't flammable, but we treated nitrogen with respect. We just knew it looked dangerous. One night my father decided to use it on himself. He had this wart on his index finger. We were watching some show on tv., and they mentioned freezing the wart off. After, a few beers, my father went to the liquid nitrogen. He told me, "Son--don't ever do this!" He literally froze the wart off with the liquid nitrogen. The wart cam off completely a few days later.

Again, only let a dermatologist apply liquid nitrogen. If they are still using it as a treatment modality?

And if you have bad acne, not cystic, I didn't have cystic acne. My acne was a lot of pimples, but most were not that deep. My successful regime was neutrogenia soap, sorry about product endorcement. Generic glycerin soap will work, but I couldn't find generic back then. Wash only 2x/daily. Apply benzoyl peroxide 2x/daily. That's it's! Don't use anything else. Don't massage the skin. Don't use any family special cures. My mother had me rubbing on liquid vitamin E, and wash time included a bleach rub. Yes--ouch!

If all that fails see a dermatologist. The low dose of antibiotics saved my skin, but I image they have better treatments today? They must have made strides in acne treatment? I never see anyone with bad skin anymore.

Good night!

Thanks for the story. Quite informative and entertaining.
8v on a 3.3v core, clocked to over 65Mhz speed AND the board still works at room temp after the experiment. I would love to see if the author would have been able to reach 100Mhz+ with a better/professional external clock.

Inspirational and thank you - За здоровье

Edit: Before I get corrected, the 328P core runs at 1.8v - 5.5v

A very cool writeup.

One of the low-temp effects that was missed: The semiconductor dopants (both donors and acceptors) don't necessarily fully ionize at liquid nitrogen temps. So changing the electron/hole concentrations of silicon (for the electronics) or III-V (for the optics) can drastically alter the electronic properties.

See, for example: http://ecee.colorado.edu/~bart/book/extrinsi.htm#freezout

It might've been easier to use a dedicated frequency synthesiser chip like the Si5351 which isn't exactly expensive, but can't argue with the results
For practical applications it is easier and cheaper to just use Cortex-M3/M4 based microcontrollers or FPGA (and I had these devboards too).

If you find FPGAs "easier" than Arduinos, you need to have your DNA sequenced for the benefit of science and humanity.

I think the intent is that building something with an FPGA is easier than trying to get the necessary performance out of an AVR with liquid nitrogen assisted overclocking. Obviously, if the Arduino is sufficient without modifications it will be way easier than the FPGA.