Hackaday Prize Entry: An E-Juice Robot

E-cigarettes are increasingly popular, with weird hipster head shops popping up in towns around the globe. While you can buy this e-juice at gas stations and just about anywhere else analog cigarettes are sold, there are inevitably people who want to mix their own propylene glycol, glycerin, water, and nicotine. For them, [conklinnick] is building The End Of An Evil Industry, an e-juice printer that automates the entire process.

This ‘e-juice printer’ is designed to mix the basic ingredients of the consumables for e-cigarettes. These ingredients are propylene glycol and/or glycerin, water, flavorings, and nicotine. [conklinnick]’s project is using different ‘stations’ and a camera slider to dispense these ingredients into a small vial. It’s effectively a barbot dispensing ingredients for silly putty instead of alcohol.

It’s a great project, and although it’s not for everybody – nor should it be for everybody – it’s a great application of homebrew tech we already have for new uses.


The 2015 Hackaday Prize is sponsored by:

DIY Air Compressor Made From Refrigerator And Fire Extinguisher

[Giorgos] wanted to build a pneumatic solder paste application tool but needed an air compressor to power it. Instead of going out and buying a compressor, he decided to build one himself. It sure is an ugly duckling but we’re impressed with it’s performance.

The air tank is an old spent fire extinguisher. The stock valve was removed and the insides were cleaned out. Out of curiosity, [Giorgos] figured out the volume by filling the tank with water, then measuring how much water came out. It turned out to be 2.8 liters. Two holes were drilled and threaded bungs were welded on to attach inlet and outlet lines.

The compressor portion is straight out of a refrigerator. Besides the compressor being free, the other benefit is that it is super quiet! Check the video after the break, you’ll be astonished. [Giorgos] did some calculations and figured out that his solder paste applicator needed about 8 bar (116 psi) of pressure. The refrigerator compressor easily handles that, filling the tank in 1 minute, 25 seconds.

On the output side of the tank resides a pressure switch for automatically filling the tank and a regulator for ensuring the solder paste applicator gets the required pressure. This isn’t the first time we’ve seen a refrigerator compressor used as an air compressor. Check out this dual setup capable of 400 psi.

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Hacking A $100 Signal Generator

Signal generators are a useful piece of kit to have on your electronics bench. The downside is that they tend to be rather expensive. If you have $100 to drop on a new toy, the MHS-5200A is a low cost, two channel, 25 MHz generator that can be found on eBay.

The downside is the software. It’s an ugly Windows interface that’s a pain to use. The good news is that [wd5gnr] reverse engineered the protocol so you don’t have to. This means other software can be developed to control the device.

When connected to a computer, this function generator shows up as a virtual USB serial port. The documentation that [wd5gnr] assembled lists all the serial commands you can send, and what they do. If you aren’t into manually setting waveforms from a serial terminal (who is?) there’s a tool for doing that automatically on Github. This takes in a CSV file describing a waveform, and programs the generator to make it for you.

The software is also compatible with Waveform Manager Plus, a free GUI tool for defining waveforms. Putting this all together, you can have a pretty capable waveform generator for less than $100.

3 Hours Until Collabatorium

This is your 3-hour warning. We’re kicking off our first ever Collabatorium and you’re invited. To join in just click the “Request to join this project” found on the left sidebar of the Hacker Channel page.

Once you’ve joined you can open up the Group Messaging for that project, one of the many awesome collaboration features on Hackaday.io. Starting at 6:30pm PDT (UTC-7) we’ll launch the Collabatorium to celebrate, discuss, encourage, and find partners for 2015 Hackaday Prize Entries. This edition of the live event is hosted by [Sophi Kravitz] and [Jasmine Brackett].

vote-shortWhile we have your attention, here’s another reminder to head on over and Vote in Astronaut or Not. Each week we draw a random hacker number for a $1000 giveaway, but only if you have voted!. The next drawing is Tomorrow so get at least one vote in right away to qualify.

The 2015 Hackaday Prize is sponsored by:

DNS Tunneling With An ESP8266

There’s a big problem with the Internet of Things. Everything’s just fine if your Things are happy to sit around your living room all day, where the WiFi gets four bars. But what does your poor Thing do when it wants to go out and get a coffee and it runs into a for-pay hotspot?

[Yakamo]’s solution is for your Thing to do the same thing you would: tunnel your data through DNS requests. It’s by no means a new idea, but the combination of DNS tunneling and IoT devices stands to be as great as peanut butter and chocolate.

DNS tunneling, in short, relies on you setting up your own DNS server with a dedicated subdomain and software that will handle generic data instead of information about IP addresses. You, or your Thing, send data encoded in “domain names” for it to look up, and the server passes data back to you in the response.

DNS tunneling is relatively slow because all data must be shoe-horned into “domain names” that can’t be too long. But it’s just right for your Thing to send its data reports back home while it’s out on its adventure.

Oh yeah. DNS tunneling may violate the terms and conditions of whatever hotspot is being accessed. Your Thing may want to consult its lawyer before trying this out in the world.

Your Brain Thinks Its Burning You, But It’s Not

In the cult classic Dune, there’s this fictional device called the “Pain Box”. If you touch it, you’ll feel like your hand is burning, but in reality, no tissue is being damaged. In the real world this is called the Thermal Grill Illusion, which was discovered back in 1896. Much to our chagrin, [Adam Davis] has just finished building a working prototype.

Sound familiar? We covered a similar project a few months ago — but unfortunately it didn’t work very well. Luckily, and boy do we love it when this happens, [Adam] saw the post, and got inspired to try it himself. He had actually designed a system years back but never got around to building it. Upon seeing the post — and the difficulties in making it work — he just had to figure it out.

So how does it work? The Thermal Grill Illusion uses alternating warm and cool bars which stimulate the temperature receptors in your skin — and confuse them. Neither the warm or cool bars are extreme enough in temperature to do any harm, but your confused little temperature receptors make it feel like you’re either burning or freezing your skin off!

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Embed With Elliot: We Don’t Need No Stinkin’ RTCs

A lot of microcontroller projects out there need some sense of wall-clock time. Whether you’re making (yet another) crazy clock, logging data, or just counting down the time left for your tea to steep, having access to human time is key.

The simplest solution is to grab a real-time-clock (RTC) IC or module. And there’s good reason to do so, because keeping accurate time over long periods is very hard. One second per day is 1/86,400 or around eleven and a half parts per million (ppm), and it’s tricky to beat twenty ppm without serious engineering.

Chronodot uses a Maxim TXCO
Chronodot uses a Maxim TXCO

Good RTC ICs like Maxim’s DS3231, used in the Chronodot, can do that. They use temperature correction logic and a crystal oscillator to get as accurate as five parts per million, or under half a second per day. They even have internal calendar functions, taking care of leap years and the day of the week and so on. The downside is the cost: temperature-compensated RTCs cost around $10 in single quantity, which can break the budget for some simple hacks or installations where multiple modules are needed. But there is a very suitable alternative.

What we’re looking for is a middle way: a wall-time solution for a microcontroller project that won’t break the bank (free would be ideal) but that performs pretty well over long periods of time under mellow environmental conditions. The kind of thing you’d use for a clock in your office. We’ll first look at the “obvious” contender, a plain-crystal oscillator solution, and then move on to something experimental and touchy, but free and essentially perfectly accurate over the long term: using power-line frequency as a standard.

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