[hansonkd]

I did something similar with a receipt printer.

a thermal usb receipt printer is like $75 dollars and easily controlled by python. Super easy to print out images and QR codes. and the autocut functionality makes it easy to segment messages. Additionally the receipt printer is nice because you can activate the bell inside as an additional "notification" and has an extra control for a cash drawer that I am thinking of hooking into to control a light or something.

I had it set up for emails and every morning it would print off my calendar.

I think the interface works well especially if you pair it with a physical control like buttons or NFC reader. That way you can issue "commands" and get output. Like I had one NFC card to make it print my calendar, one for unread emails, etc.

I have some more features I want to add to it. Its very fun way to cut down on screen time, but ironically i have spent more screen time coding with it and setting it up then it probably has saved me. lol.

[autoexec]

Receipt printers are fun but take care not to buy toxic paper https://www.consumerreports.org/cro/news/2014/03/the-health-...

[z2]

The most mainstream phenol free thermal paper out there is one made from a branded chemical "pergafast" which is supposedly based off of urea. This is increasingly the type used by big brand stores where the paper is advertised as BPA and BPS free. It appears safe in studies so far in terms of not being absorbed through the skin nor endocrine disrupting, but is also known to be highly toxic to aquatic life. There's another chemical related to vitamin c branded "Alpha Free" but it's harder to find.

https://www.sciencedirect.com/science/article/abs/pii/S02732...

[account42]

Always remember that X-free or similar claims of not being toxic only means that the substances used instead of X are not yet known to be as toxic (or at just that the laws haven't caught up yet). It isn't guarantee that the new product is any safer than X and it might even be less safe. After all, the X in question was also seen as perfectly fine at some point.

[ComputerGuru]

It's actually known that many of the alternatives companies have substituted for BPA are equally or more dangerous; they're just not blacklisted by the FDA so companies continue to use them with impunity.

https://www.nationalgeographic.com/premium/article/bpa-subst...

https://archive.is/Bu6TE

[amelius]

Does this warning also hold for thermal label printers?

I have this one: https://www.creativebloq.com/reviews-niimbot-d110

[kevin_thibedeau]

Brother P-touch uses thermal transfer where pigment is bonded to a substrate rather than a chemical phase change and is safe.

[autoexec]

Yes, but it looks like you can get tape for it that is BPA/BPS free.

[kragen]

Assuming BPA is what you're worried about (it's not "toxic" by the usual definitions but still something you may want to avoid) there isn't another mainstream option.

[noja]

> it's not "toxic" by the usual definitions

iirc if you have wet hands you absorb way more and it is toxic

[kragen]

I can't find any evidence that anyone has ever died from bisphenol-A poisoning. Searching the medical literature finds no case studies of emergency-room visits or dying epoxy painters.

Rat studies like https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&d... and https://www.researchgate.net/publication/236345183_Pathologi... come up with acutely lethal oral doses around 2000–3000 milligrams per kilogram, by which measure it has about the same toxicity as table salt. It also has about the same pharmacokinetic half-life as table salt. The concerns (documented meticulously in https://en.wikipedia.org/wiki/Health_effects_of_Bisphenol_A) are largely about its possible effects as a xenoestrogen, and in particular its potential to cause obesity. There have also been concerns that chronic exposure might be carcinogenic, but so far those haven't panned out, so it's clear that if BPA exposure has an effect on cancer risk, either positive or negative, it's very small in magnitude.

I don't think there's anything in the obesity concern, because the obesity pandemic seems to be associated with eating ultra-processed food rather than handling thermal-printer receipts or drinking out of Nalgene bottles. My best guess is that we'll find out that a few food additives that became popular 50 years ago upset the intestinal microbiome in a way that promotes obesity.

In the meantime, though, it doesn't seem unreasonable to try to minimize your exposure to the stuff, even if ultimately it turns out to be harmless or only slightly harmful. But I wouldn't worry about it.

Eating synthetic imitations of food, though, seems overwhelmingly likely to be bad for you.

[CapstanRoller]

>I can't find any evidence that anyone has ever died from bisphenol-A poisoning.

That's like talking about cigarettes and claiming people don't die from nicotine, therefore smoking isn't a problem. Missing the point terribly.

[kragen]

On the contrary, nicotine poisoning is common, the lethal dose in humans is relatively well characterized (though higher than most poisons: 500–1000mg/kg) and there are many case studies of nicotine poisoning in the medical literature, many of which are life-threatening and some of which are even lethal: https://en.wikipedia.org/wiki/Nicotine_poisoning. Moreover, nicotine has been widely used to kill insects in the past. Consequently, there are well-established occupational safety limits. None of these things are true of bisphenol-A, even though it is produced in much larger quantities than nicotine ever has been.

Perhaps your intended reference, however, is to the other toxic components of cigarette smoke, such as benzo[a]pyrene. That is, cigarettes kill something like one out of ten people, but the vast majority of those deaths are not due to nicotine. (Except in the indirect sense that nicotine is addictive and induces people to smoke cigarettes so that they are exposed to the other poisons in the smoke.)

Very well, then. What are the other toxic components of thermally printed receipts you're concerned about?

I'm open to hearing what point you think I'm missing, but so far all you've done is strike a pose of fatigued knowingness. If you have knowledge to share on this matter, by all means, share it; certainly I won't be the only one who needs the point spelled out for them, because as dumb and uninformed as I admittedly am, I doubt I'm the dumbest or least informed person reading this thread.

[account42]

> My best guess is that we'll find out that a few food additives that became popular 50 years ago upset the intestinal microbiome in a way that promotes obesity.

I bet it's mostly just sugars. That and plain overconsumption and lack of exercise. Excacerbated by societal shifts that mean people don't get shamed into behaving better as much as they used to be. Trying to blame evil chemicals for making you fat is just a cope for those that don't want to take any responsibility for their unhealthy lifestyle - even if there are additives that "promote obesity" it's going to be a relatively minor effect compared to the basic energy in vs. energy out balance.

[kragen]

It sounds like you aren't familiar with the basics of what is known in the field, because the theory you're promoting has been known to be wrong for decades. It's kind of the Flat Earth Theory of obesity.

The cause might be sugars, but they'd have to be sugars that were little used 50 years ago when the obesity pandemic began. One promising candidate was high-fructose corn syrup, with a promising hypothesis about how a fructose/glucose ratio of 1:1 was harmless. That hypothesis was always somewhat unlikely and basically didn't pan out. Glucose syrup was also an interesting hypothesis‚ but fructose/glucose hypotheses all run up against the sucrase-isomaltase problem: people in some places, such as the US, ate plenty of sucrose before 01974, and it gets split into fructose and glucose in the small intestine. So you need an explanation of why the modern sugar-heavy diet has such dramatically different health effects from historical sugar-heavy diets. Maybe it's fucose? Chlorinated sugars like sucralose? Massive galactose doses? You could be right, but you've chosen to take on a heavy burden of proof there.

As for your "shame people who don't want responsibility" ideas, I suggest reading https://slatestarcodex.com/2015/01/12/the-physics-diet/, which begins:

> There are at least four possible positions on the thermodynamics of weight gain:

> 1. Weight gain does not depend on calories in versus calories out, even in the loosest sense.

> 2. Weight gain is entirely a function of calories in versus calories out, but calories may move in unexpected ways not linked to the classic “eat” and “exercise” dichotomy. For example, some people may have “fast metabolisms” which burn calories even when they are not exercising. These people may stay very thin even if they eat and exercise as much as much more obese people.

> 3. Weight gain is entirely a function of calories in versus calories out, and therefore of how much you eat and exercise. However, these are in turn mostly dependent on the set points of a biologically-based drive. For example, some people may have overactive appetites, and feel starving unless they eat an amount of food that will make them fat. Other people will have very strong exercise drives and feel fidgety unless they get enough exercise to keep them very thin. These things can be altered in various ways which cause weight gain or loss, without the subject exerting willpower. For example, sleep may cause weight loss because people who get a good night sleep have decreased appetite and lower levels of appetite-related hormones.

> 4. Weight gain is entirely a function of calories in versus calories out, and therefore of how much you eat and exercise. That means diet is entirely a function of willpower and any claim that factors other than amount of food eaten and amount of exercise performed can affect weight gain is ipso facto ridiculous. For example, we can dismiss claims that getting a good night’s sleep helps weight loss, because that would violate the laws of thermodynamics.

> 1 and 4 are kind of dumb. (...)

4 is your position. Read the article to see why it's dumb. It's a short, easy read.

Also I suggest reading https://slatestarcodex.com/2017/04/25/book-review-the-hungry..., a review of The Hungry Brain by neuroscientist Stephen Guyenet, who specializes in nutrition. Also, and I know this may be a big ask, maybe read an actual book on the topic too. Also, you would probably find it illuminating to read https://www.bpni.org/wp-content/uploads/2020/10/2020-UPFs-ob..., "Ultra-processed food and the risk of overweight and obesity: a systematic review and meta-analysis of observational studies," and although observational studies aren't the strongest form of evidence (you could hypothetically have some kind of widespread undiscovered brain infection that both causes obesity and also makes you eat Cheetos and Cheez Whiz, without the latter causing the former, or fat people might settle for ordering Domino's Pizza because it's too hard for them to travel all the way to Whole Foods), there are also randomized clinical trials showing the same thing.

Maybe also https://link.springer.com/content/pdf/10.1007/s13668-024-005..., "Ultra‑processed Food and Obesity: What Is the Evidence?", whose summary says:

> Greater UPF [ultra-processed food] consumption has been a key driver of obesity. There is a need to change the obesogenic environment to support individuals to reduce their UPF intake. The UPF concept is a novel approach that is not explained with existing nutrient- and food-based frameworks.

It's shorter than the SSC posts I linked, but it demands a higher level of literacy.

[desdenova]

> My best guess is that we'll find out that a few food additives that became popular 50 years ago upset the intestinal microbiome in a way that promotes obesity.

People can get drunk enough to fail a breath test, just from eating industrialized bread.

There's so much chemical crap added to industrialized food we're not even aware of, unless we send each item to a lab for testing before we eat.

But yeah, people sure must be getting fat because the McDonald's cashier gave them a receipt made of bad paper...

[kragen]

> People can get drunk enough to fail a breath test, just from eating industrialized bread.

I don't think this is unique to industrialized bread; in cases like this, what the yeast are fermenting is starch in the bread, which has been the main component of bread as long as there has been bread. They aren't fermenting the xanthan gum, guar gum, calcium propionate, titanium dioxide, etc. In fact, if anything, I'd think the anti-fungal preservatives like propionate would tend to make industrialized bread harder for yeast to ferment.

[gzalo]

I wonder if it's feasible to make diy Thermal paper using lemon juice, like the old "invisible ink experiment"

[desdenova]

Should be easy enough to test if you have a thermal printer.

Just spread lemon juice on paper, wait for it to dry, and try printing on it.

[nik282000]

Great minds. My thermal printer spits out the weather every morning and if any important devices fall off my network it prints a notification.

[aschmelyun]

Receipt printers are a blast! I had a project from a couple years ago printing out GitHub tickets using a similar setup to what I have for this dot matrix printer.

[ustad]

Whats the printer you have? I’ve been thinking of getting one and did not know about the notification and external feature you mention.

[hansonkd]

I have a Rongta RP331.

The thing I wish it could do different is that when printing a single line, the autocutter hides it, so you have to line feed about 5 times until the line you printed is visible.

If i did it different, maybe i would try to find a printer that is able to do reverse line feed so I can "peek" at a single line and then not waste paper. but i think those are about 3-4 times more expensive.

[PaulHoule]

There are a lot of cheap Chinese dot matrix printers. As an American if you search by mm size you will find those, if you search by inches you will find more reputable (and culturally sensitive) brands.

I bought two Chinese printers, one burned up pretty quick when I was testing it but I might have been printing too much black. The other is fine I think but really I am not so motivated to make thermal prints when I have a good quality inkjet. (My best thermal print was a small Lusamine

https://safebooru.org/index.php?page=post&s=view&id=1821741

which demonstrates how Nintendo official art is designed to render on cheap screens like the Nintendo 3DS)

[mtoohig]

Please share some of your code, I would like to see and get a feel for some personal ideas.

[Instantnoodl]

I use Thermal Printer for a different use-case (TTRPG stuff). Feel free to check it out :)

https://github.com/BigJk/snd

[jabroni_salad]

wow I love this. I like using spellcards but havent had a good solution for items... might need to buy a receipt printer now.

[hansonkd]

I am currently working on an "input" interface to scan resposnes that I write from my typewriter and am planning on releasing a github repo on it when im done. conveniently you can type directly on the receipt printer if the response is short.

Right now all my credentials are hardcoded so i can't push out what I have without some cleanup, but I can point you to some of the libraries: python-escpos and nfcpy were what I used for the bulk of it.

[meling]

Last paragraph made me laugh

At least you did something cool with your screen time!

[AStonesThrow]

Whatever vendor(s) decided that the restaurant industry needed to switch over to thermal printers, I hope Cory Doctorow has a chat with them.

"Let's just tape this thermal receipt to your to-go container, and ... refund? What do you mean refund?"

[bombcar]

Thermal printers are cheaper because you only have to buy paper, no ribbon or ink.

However, thermal receipt printers at restaurants seem to be among the cheapest ones around - you can get thermal printers that result in receipts that withstand decent temperatures (but, obviously, not all).

Many shipping labels are printed by direct thermal printers and those labels stand up quite well. Check Zebra for examples.