Bluetooth and Arduino Vaporizer Upends Stoner Stereotypes

Back in the day, stoners were content to sit around, toke on a joint, mellow out, and listen to the Grateful Dead or something. Nowadays, they practically need a degree in electrical engineering just to get high. [Beiherhund] sent us his VapeBox build. Like so many projects on Hackaday, we’re not going to make one ourselves, but we appreciate a well-done project.

First off, there’s a home-built induction heater. A 30A current sensor and switch-mode power supply regulate the amount of juice going to the coil that surrounds the heating chamber. [Beiherhund] discovered that brass doesn’t have enough internal resistance to heat up in an induction heater, so he built a stainless steel insert into the chamber. Optimal temperature is monitored from outside the chamber by a MLX90614 IR thermometer.

Fans, controlled by PWM, keep the box cool. Lights, an LCD, an HC-05 Bluetooth unit, and everything else are all tied to the obligatory Arduino that serves as the brains. A cell-phone application lets [Beiherhund] control all the functions remotely. (We’re guessing, just because he could.) It’s wrapped up in a nice acrylic case. The video, embedded below, starts with real details at 4:28.

Before you loyal Hackaday commenteers get on your high horses (tee-hee!) bear in mind that smoking dope is legal in a number of states in the USA, and that Hackaday has an international readership. We don’t encourage drug abuse or soldering in shorts and flip-flops.

63 thoughts on “Bluetooth and Arduino Vaporizer Upends Stoner Stereotypes

  1. Isn’t this induction heater just a tiny bit of overkill just to heat up small amounts of plant mass? I’d rather go with either Kanthal-D wire wrapped over glass tube or heating element from cheap, chinese soldering station…

    1. I get my high from breathing 21% Oxygen, but I do appreciate a well executed build. I don’t understand the induction heating either. I assume the purpose of the build was to create vaping “juice” without contamination of papers or other consumables. Putting the stainless sleeve in the induction heater could increase the potential for contamination with Chromium coming from the stainless.
      I would think superheated air blowing across the weed would do a better job. Then you could cool down the smoke for immediate consumption or bubble it through a vaping solution if the vaping “juice” was the desired end product. Using that method could potentially make cleanup easier.
      No judgement, be safe.

      1. The idea behind vaping is to get plant matter hot enough to vaporize active substances, but not hot enough to cause thermal decomposition. Amateur induction heating doesn’t offer precise temperature control, the entire feedback loop is too big to work efficiently. You need a loop that won’t overheat by more than one degree Celsius. My vaping experience is limited to hookah with ordinary tobacco molasses, but that’s a great example of problems caused by overheating. Burned molasses is no fun at all..

          1. No disrespect on your build.
            I think what we are saying is if you want to selectively vaporize a specific substance while keeping other contaminants to a minimum then the heat source needs finer control.
            Specific to Herb I admit ignorance.

          2. @RandyKC, can’t seem to reply directly to you here. I totally understand that some substances need to be maintained at a specific temperature (e.g. when making cheese) but with herbs you have a lot of play. You can vary over a 40*C range and be fine. “The aromatic terpenoids begin to vaporize at 126.0 °C (258.8 °F),[31] but the more bio-active tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) do not vaporize until near their respective boiling points: THC 157 °C (315 °F),[32] CBD 160–180 °C (320–356 °F),[32] and CBN 185 °C (365 °F” – Wikipedia.

            So what i’m saying is that no herb vaporiser on the market either needs to have precise control to within 1*C or has a limit to prevent exceeding a single set temperature by 1*C. They all either allow you to vary the temperature or have a target temperature that they will hover around given the fluctuations in environment and conditions (e.g. inhaling).

            Once I have better calibrated the IR thermometer, it’ll likely just be coding that prevents me from having better control over the temp, At the moment I’m not bothered if the temp overshoots the target by 5-10*C and then drops back down to stick at the target, I just don’t load in the herb until it has stabilised.

          3. Limit on reply stacking is a WordPress limitation.
            Looks like in your case you actually WANT to cycle over a 40 degree range to vaporize all the desired compounds. Interesting. That type of PID control could be useful in other areas like essential oil extraction. I still think it would be more accurate to use heated air since your process limits your batch size. Then again it may be more efficient. Please keep posting on your progress!

          4. Limit on reply stacking is a WordPress limitation.
            Looks like in your case you actually WANT to cycle over a 40 degree range to vaporize all the desired compounds. Interesting. That type of PID control could be useful in other areas like essential oil extraction. I still think it would be more accurate to use heated air since your process limits your batch size. Then again it may be more efficient. Please keep posting on your progress!

            I think the heating process in this design is about 70% conduction and 30% convection as I can feel that the air is very hot when I exhale and hold my hand over the chamber tube. I was initially uncertain about going for a full convection design as I thought temperature control would be more difficult and glass is also harder to work with. However I’ve learnt quite a bit during this project (I’m fairly new to Arduino and electronics) so I might have a go at a portable design, which convection heating is perfect for due to its smaller size and power requirements.

            Cheers,

    2. Yeah definitely a bit of overkill. I wanted to go for an AC-powered vape before trying my hand at a portable one, which would definitely need to rely on Kanthal-D or nichrome wire

  2. Take switchmode PSU, put another switchmode PSU behind it… yo dawg…
    It really isn’t that hard to modify the feedback loop of the main power supply, this is just being lazy (and wastes power).

    1. Beiherhund here – The first SMPSU doesn’t have an LC filter so the output voltage ripple will (and did) kill the induction coil. This is my second induction coil after the first one fried it’s MOSFETs. Sure, I can make my own LC filter for the output easy enough but then comes issue #2. I need a 12V rail for the fans and a minimum ~7V for the 5V voltage regulator. Actually, I need to power the Arduino on more than 7V through the VIN pin so let’s bump that minimum up to 9V for ease of mind. The third thing is that I’d much rather hack my way into the OpAmp of a low voltage DC circuit than the OpAmp of a mains power supply. I also thought it better if I use a SMPSU designed for regulating voltage and current than one that is meant to output a fixed 12V.

    2. You are wrong. Technically speaking, you have to put something IN something to have a yo dawg.
      By the way, how do you get italic in comments? I HATE when people use caps for emphasis.

    1. I routinely solder parts of my quadcopter in the early AM, naked, while I drink my coffee. After a decade of practice, you don’t really have accidents anymore.

    2. Solder (preferably lead free – it is hotter), naked knees, what can go right?
      Ok, I did it. Got solder on my knees twice, and that was twice too many, even if did not bring any damage and just hurt.

      1. Overkill? I thought it seemed hella slow, 60 seconds for 180c? I don’t have patience for that, make it 5 seconds! And i don’t even smoke haha!

        But The noise and The fans…. I man this is a Nice (very) project but i was just imagining it so differently!

        1. Aww for Christ sake, put my comment in the proper place instead.

          Anyways, also did the solder in my shorts thing. 10awg wire, lots of solder. Dripped down on my knee, got stuck in some hairs so i couldn’t brush it off… Good times! :D

        2. I’ve got the warm-up time down to 25 seconds now. Changed a bit of the code which means it overshoots the target and then takes 5-10 seconds to correct itself.

          Fans can also be turned off, they’re most useful for maintaining a lower temperature and preventing over heating at high temperatures.

  3. Using an IR thermometer is a ‘bit’ challenging with a few exceptions (measuring human skin temperature is one of them). It is sad to see Jamie and Adam and every chef in the world to trust them merrily with nonsense results.Sorry to say, but based on the Imgur article, the photos and the video, I’d guess in this case the result is very incorrect, too.

    (The IR thermometer basically measures the amount of thermal radiation entering it and it is only emitted by the object of interest in the ratio of its surface emissivity, the rest being reflected from the environment – often specularly!)

    What? No signing in with the Hackaday ID?

    1. I remember the Mythbusters discussing emissivity. I believe Adam said he has his own logbook with data correlated with actual thermistor readings.
      They leave a lot out of the show for time reasons.

      That said, one should at least read the manual that comes with their IR thermometer. There’s usually instructions for changing the settings and warnings about sunlight ect.

    2. Hey Gary, in case you’re interested here is my correction for emissivity based on calibration with the K-type thermocouple:

      float tempCorrect(float tempOb, float tempAm){
      const float ems = 0.283;
      tempOb = (tempOb*tempOb);
      tempOb = (tempOb*tempOb);
      tempAm = (tempAm*tempAm);
      tempAm = (tempAm*tempAm);
      float result = sqrt(sqrt((((tempOb – tempAm) / ems) + tempAm)));
      return result;
      }

      1. Hi kaleun96,

        Fantastic to find out, that you were aware of this to begin with!

        The really tricky (read: always impossible in theory and often in practice) part is to ignore the variable reflected radiation. Unless one has found a way to build a perpetuum mobile, everything lacking from the emissivity is reflectivity. No amount of calibration (unless the environment is calibrated too) will solve that. For polished metal the situation is especially bad… polished silver has emissivity of 0.02 and reflectivity of 0.98. A strategically positioned dab of soot would solve this problem. And yes, if the measured object is very hot, the T^4 term mitigates things.

        In your system the problem might be purely theoretical, although as a guess, the temperature of the rest of the system (inside the box) should affect the measurement. Not sure how critical the exact temperature is for the actual application, though. :-)

        And in Mythbusters, I remember seeing them measuring the temperature of a shiny metal container from which their own image was reflected… :-D

        1. Hey Gary,

          You definitely know more about this then myself so I might pick your brain if you don’t mind.

          ” everything lacking from the emissivity is reflectivity” I understand this issue but I’m unsure how changing the emissivity of the sensor affects this. In my example I’m changing the emissivity ad hoc, i.e. after measurement. But if you were to change the default emissivity value of the sensor, does this tell the sensor how to deal with the increased reflectivity or is it simple inputting a value into a formula to attempt to correct for the decreased emissivity? I imagine it does this based on the ambient temperature readings but what you’re saying is that you can’t fully account for the effect of reflectivity on the readings, you can only try to estimate them?

          1. Well, I’m nowhere near an expert on this subject, but I’ve stumbled on it often enough, so it has become a bit familiar. I built my first scanning thermal camera using an early Melexis sensor way back in the early 2000’s, and have been toying with them since. Those days the sensors were analog and the sensor (ambient) temperature had to be measured and taken into consideration. Nowadays the processor inside the component does this for you.

            Increasing the emissivity of the object (not sensor) solves the problem to a great degree, since it simultaneously reduces the reflectivity. The sensors are always calibrated for perfect emissivity of 1.00 and some materials (water, skin, carbon soot) are quite close to that. Mix in the T^4 term of thermal radiation and the result is that for a hot object of reasonable emissivity, the measurement can be rather correct. On the other hand, for warmish shiny metal objects, it never is. In the lab, an often used quick fix is to stick the object to the flame of a candle and let it get black with the soot. An acetylene torch is even better. Unfortunately, the soot is not very durable, but in your application the ‘object’ is in protective casing, which might solve that. And matte black is always stylish.

            One other thing to keep in mind is that many sensors of this kind have a very wide field of view. And the measured object had better to fill it, otherwise one is measuring a mix of the object and the background. The sensor family you mentioned has many variants in this respect.

            Finally, if there is a need to measure temperature accurately and not a need to do it in a contactless manner, a thermopile sensor is definitely a wrong choice. But the coolness factor may outweigh reason, of course. :-)

        2. Thanks for the info in your post below!

          Any suggestions for colouring brass matte black that can withstand a high temperature (250C) and not produce much in the way of fumes?

          By the way I have the MLX90614ESFDCI, so only 5 degree FOV. This was something I considered beforehand so I paid a bit extra for the narrowest view. I believe it also is better at handling thermal gradients than the other models.

    1. At least we’re one of the most peaceful and satisfied people on the planet. We don’t do that whole drone bombing children and mass shootings thing that America does, but we need to be medicated?

  4. Mine was just a (brand new) soldering iron with the bit removed, a 2L glass fruit juice bottle, and some tubing. Held together with blu-tak and tape. Did the job! It’s not the sort of thing that really needs a lot of work putting in.

    One problem with mine, was having to wait til it cooled down before you could replace the weed. Still, never mind, quit smoking that years ago. Anything new happening in the world of crack pipes?

  5. “George Bush(Sr.) says ‘we are losing the war on drugs’, well you know what that implies? There’s a war going on and people /on/ drugs are winning it… ahh-hahaha… well- what does that tell you about drugs? Some smart, creative motherfuckers ln that side… they’re winning a war and they’re fucked up. A lot of y’all don’t even know you’re fighting, do you? You’re sitting there ‘well fuck, I’m watching Saturday Night Live ::hits a joint:: …are we winning?’ … … You know the War on Drugs is hypocrisy man, thats why it’s not going to work- it’s because it’s a fucking lie.”

  6. “Why is marijuana against the law? It grows naturally upon our planet… doesn’t the idea of making nature against the law seem to you a bit… …unnatural? It’s nature. How do you make nature against the fucking law? Grows everywhere, serves a thousand different purposes- all of them positive. To make marijuana against the law is like saying _God_ made a mistake- like on the Seventh Day… ‘There it is- My Creation. Perfect and Holy in all ways… … … … … … …Oh… My… Me… … I went and left fucking pot everywhere… …I should never have smoked that joint on the third day. That was the day I created opossums. hahaha.. still gives me a chuckle… if I leave pot everywhere that will give humans the impression ::gasp:: that they should use it. ::sigh:: …Now I have to create Republicans.’

    I believe that God left certain drugs on our planet to help speed up and facilitate our evolution. Do you think magic mushrooms growing atop cow shit was a fucking accident? Where do you think the term ‘that’s good shit’ came from? Why do you think Hindus think cows are Holy? ::mimes blinking, shaking head and blinking as if during a moment of clarity while tripping:: ‘… …Holy Shit'”

    -Bill Hicks

    1. It is illegal because it stinks even worse than tobacco, which should also be illegal. If it stinks = definitely not good. Now if you want to eat either, go ahead. Just no smoking and stinking up the atmosphere.

  7. Whoa – The BIG Gubbment (you voted for) sniffs your Mandated “Smart” meter which will send power usage patterns to the guys in black helicopters who will decide it is 99% likely you’re NOT drawing bursts of mains current at midnight every minute or two just to make MANY slices of toast. Next step: Your door is breeched, your dog is shot, then you are sent to the Coolie for years on end. Welcome to America!

    1. It may sound like [Drone] is exaggerating, but he’s not very far off. :/
      Better watch out if they see you buying cold medicine and pool supplies in the same purchase.

    2. Easy way around that is have two loads where one load operates inversely to the other so that the current is constant regardless which is operating. Maybe have the box fan in the room slow down when the vape is vaping?

  8. This project definitely flies in the face of the government assertion that smoking pot affects the brain in a negative, harmful manner; and that potheads are essentially deadbeat losers.

    It boggles the mind to think that so many brilliant people may be locked away in prison for engaging in an activity that harms nobody; and yet alcohol is accessible everywhere, and not only harms the body, but others in the form of vehicle accidents and violent physical abuse.

      1. You’re supposed to explain what and why, when you accuse someone of that.

        If you’re talking about the old chestnut, marijuana vs alcohol, the statistics are basically alcohol is hugely harmful and marijuana pretty benign, society-wise. Marijuana has it’s problems but booze is much worse. To put it in a nutshell.

        Same for heroin, actually, does no physical harm, if it were legal again, nearly all the problems associated with it would be gone.

        1. As all people have confirmation bias it isn’t an accusation – it’s a fact. It’s also a fact that people on marijuana test worse for intellectual tasks.

          Heroin not doing any physical harm?!? Didn’t realize you were a crank…

          1. It’s also a fact you can find studies which say the exact opposite of your studies. Be cause well, BIAS.

            Its fucking stupid that a PLANT is illegal and consumption of said plant is illegal when you can go to the liquor store and by enough liquid death to kill yourself a billion times over when the plant is damn near impossible to kill yourself with based on consumption alone. You can argue against stoned driving and I will agree with you, but so is driving while on just about every medication there is. If it says “may impair ability to operate machinery” on the box or bottle, you can commit OWI while using it…

            It’s a fact the authorities make BILLIONS of dollars off of a war they cannot win. So who is winning, again?

            It sure the fuck doesn’t sound like the government is losing. And don’t kid yourself, the war on drugs has ZERO to do with public health and everything to do with the almighty dollar.

          2. Of course people perform worse on intellectual tasks on marijuana, they’re stoned! That’s the point! It’s no reason to lock people up for getting involved with it though, or fine people, and all the other nonsense.

            If you’re talking about permanent effects, after the drug’s worn off, I’d like to see your source, cos far as I know that’s not true at all. I also don’t think there’s anybody who still thinks marijuana is less harmful than alcohol, by pretty much any and every measure. It’s not illegal for harm reasons anyway. It’s illegal largely because it makes black men rape white women, makes white women want to have sex with black men, and because Mexicans smoke it. Those are the reasons given when that law was made. Also some murderer claimed he turned into a bat, and therefore wasn’t responsible for the murder. He got away with it, too. This sounds comical, and it is, but it’s actually the truth of what happened. Awful, isn’t it?

            All the bogus health claims were added later, to try shore up an unfair and stupid law. Over the years they’ve been proved wrong, too.

            Of course smoking anything is bad for your health, and drugs will intoxicate, but it’s every adult’s right to make that choice themselves.

            As far as heroin, actually opiates are very “clean” drugs. They affect only the brain and bowel. Medical heroin has no adverse effects at a proper dose, except it can be habit-forming, and addictive.

            Street heroin is different of course, because it’s in the hands of criminals. Legally-supplied heroin, as is available in some parts of Europe, is pure and measured. That means no overdoses, no abscesses. It also means it’s cheap enough to smoke rather than inject. Smoking heroin is pretty much completely safe. It’s almost impossible to overdose, one simply falls asleep long before that can happen.

            Heroin’s illegal status is the cause of most of the problems it’s users have.

            The addictiveness is over-stated, and causes more fear than it should in people who don’t really know about it. Simply put, would you likewant to be addicted to a drug? Most people wouldn’t, even if they could get it cheaply and safe. To become addicted is a choice one makes, early on. You either stop, or carry on and let it happen. For that that would choose addiction, simply maintaining their dose is all they need. Or tapering down if they want to stop.

            The over-arching issue is that the government aren’t my parents. I’m a grown-up, and if I’m not harming others, my life is my own business. You disagree with that? Not for “other people”, for you. Since we’re all “other people”.

  9. http://www.druglibrary.net/schaffer/History/whiteb1.htm

    Worth reading, the history of how the anti-marijuana law was actually made. Comical and horrible at the same time. Nice, conversational style, and backed up by quotes and references. The reasons for the law really, really, aren’t what most people would expect them to be.

    Cliff Schaffer has assembled a very interesting and useful online library on the subject in general, but that article is my favourite.

  10. Firstly, nice overkill!
    On the lazy stoner stereotypes, I will only say that some of the laziest people i’ve worked with would go to extreme lengths to avoid work. Now that I think of it, they may have been stoners, too!

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