Ask Hackaday: Bitten By The Crocodile Clip

February 25, 2017 by 69 Comments

I have a love/hate relationship with the crocodile clip. Nothing is so quick to lash together a few half-baked prototype boards on your desk, but nothing ends up in such a tangle so quickly, either. I love the range of pretty colors that crocodiles come in, as well as the easy ability to just clip on to the side of a PCB, or any old loose wire. But they come loose, they can have intermittent contacts, and we’re not even sure if there is such a thing as a current rating for them.

When [WarriorRocker] wrote in asking what we use instead of crocodile clips, he included a photo that sent a chill down my spine, from a review of some clips on Amazon. I’ve seen this one in real life. And what’s worse is the one with the loose wires that sometimes make contact with the spring-clip body and sometimes not.

After an hour-long debugging session about twelve years ago now, such an intermittent croc caused us to make a lifelong vow. All of our croco-clips have been disassembled, manually inspected, and many of them soldered together. When I buy new ones, I check them all before mixing them in with the known-goods. Even thinking about this now makes me want to pull back their little rubber booties just to make sure. Continue reading “Ask Hackaday: Bitten By The Crocodile Clip” →

Tindie Chat: All About Certifications

February 25, 2017 by 9 Comments

The chat functionality on Hackaday.io is quickly turning into the nexus of all things awesome. This Tuesday, February 28th, everyone’s favorite robotic dog is talking certifications. Everything from FCC to UL to OSH to CE and the other CE is on the table. If you want to build hardware, and especially if you want to build a product, this is the talk for you. Join us for the next Tindie Chat on Hackaday.io.

Every month or so, we round up Tindie sellers, buyers, and the Tindie curious to talk about the issues facing hardware creators. We meet up in the Tindie Dog Park to talk about all things Tindie and hardware creation. If you want to know anything about certifications — whether you’re selling on Tindie or not — this is the virtual meetup for you.

This chat is going down Tuesday, February 28th at 11:00 AM PST (or 19:00 GMT). Want to join in the chat? Head on over to the Tindie Dog Park and request to join the project. Then, just head over to the chat by clicking on the ‘Team Messaging’ button. If you have a question, we have a spreadsheet.

There are a lot of experienced product designers over on Tindie, and this is a prime opportunity to learn some of the hard lessons these Tindie sellers have already experienced. Don’t miss this, it’s going to be great.

Growing Plants On Mars… On Earth

February 25, 2017 by 61 Comments

One of the biggest challenges of traveling to Mars is that it’s far away. That might seem obvious, but that comes with its own set of problems when compared to traveling to something relatively close like the Moon. The core issue is weight, and this becomes a big deal when you have to feed several astronauts for months or years. If food could be grown on Mars, however, this would make the trip easier to make. This is exactly the problem that [Clinton] is working on with his Martian terrarium, or “marsarium”.

The first task was to obtain some soil that would be a good analog of Martian soil. Obtaining the real thing was out of the question, as was getting similar dirt from Hawaii. [Clinton] decided to make his own by mixing various compounds from the hardware store in the appropriate amounts. From there he turned to creating the enclosure and filling it with the appropriate atmosphere. Various gas canisters controlled by gas solenoid valves mixed up the analog to Martian atmosphere: 96% dioxide, 2% argon, and 2% nitrogen. The entire experiment was controlled by an Intel Edison with custom circuits for all of the sensors and regulating equipment. Check out the appropriately dramatic video of the process after the break.

While the fern that [Clinton] planted did survive the 30-day experiment in the marsarium, it wasn’t doing too well. There’s an apparent lack of nitrogen in Martian soil which is crucial for plants to survive. Normally this is accomplished when another life form “fixes” nitrogen to the soil, but Mars probably doesn’t have any of that. Future experiments would need something that could do this for the other plants, but [Clinton] notes that he’ll need a larger marsarium for that. And, if you’re not interested in plants or Mars, there are some other interesting ramifications of nitrogen-fixing as well.

Continue reading “Growing Plants On Mars… On Earth” →

Simple And Effective Car Lock Jammer Detector

February 25, 2017 by 40 Comments

[Andrew Nohawk], has noticed a spike of car break-ins and thefts — even in broad daylight — in his native South Africa. The thieves have been using remote jammers. Commercial detectors are available but run into the hundreds of dollars. He decided to experiment with his own rig, whipping up a remote jamming ‘detector’ for less than the cost of a modest meal.

Operating on the principle that most remote locks work at 433MHz, [Nohawk] describes how criminals ‘jam’ the frequency by holding down the lock button on another device, hoping to distort or outright interrupt the car from receiving the signal to lock the doors. [Nohawk] picked up a cheap 433MHz receiver (bundled with a transceiver), tossed it on a breadboard with an LED connected to the data channel of the chip on a 5V circuit, and voila — whenever the chip detects activity on that frequency, the LED lights up. If you see sustained activity on the band, there’s a chance somebody nearby might be waiting for you to leave your vehicle unattended.

If you want to know more about how these jamming attacks work, check out [Samy Kamkar’s] talk from the Hackaday SuperConference.

Continue reading “Simple And Effective Car Lock Jammer Detector” →

The Fab Lab Next Door: DIY Semiconductors

February 25, 2017 by 39 Comments

You think you’ve got it going on because you can wire up some eBay modules and make some LEDs blink, or because you designed your own PCB, or maybe even because you’re an RF wizard. Then you see that someone is fabricating semiconductors at home, and you realize there’s always another mountain to climb.

We were mesmerized when we first saw [Sam Zeloof]’s awesome garage-turned-semiconductor fab lab. He says he’s only been acquiring equipment since October of 2016, but in that short time he’s built quite an impressive array of gear; a spin-coating centrifuge, furnaces, tons of lab supplies and toxic chemicals, a turbomolecular vacuum pump, and a vacuum chamber that looks like something from a CERN lab.

[Sam]’s goal is to get set up for thin-film deposition so he can make integrated circuits, but with what he has on hand he’s managed to build a few diodes, some photovoltaic cells, and a couple of MOSFETs. He’s not growing silicon crystals and making his own wafers — yet — but relies on eBay to supply his wafers. The video below is a longish intro to [Sam]’s methods, and his YouTube channel has a video tour of his fab and a few videos on making specific devices.

[Sam] credits [Jeri Ellsworth]’s DIY semiconductor efforts, which we’ve covered before, as inspiration for his fab, and we’re going to be watching to see where he takes it from here. For now, though, we’d better boost the aspiration level of our future projects.

Continue reading “The Fab Lab Next Door: DIY Semiconductors” →

Ham Goes Nuts For Tiny Transmitter

February 24, 2017 by 26 Comments

What’s the minimal BOM for a working amateur radio transmitter? Looks like you can get away with seven parts, or eight if you include the walnut. You’ve got to have a walnut.

Some hams really love the challenge of QRP, or the deliberate use of low-power transmitters to provide a challenge to making long-distance contacts. We’ve covered the world of QRP before and noted that while QRP rigs don’t throw a lot of power, it doesn’t mean that they need to be simple. Some get quite complex and support many different modulation schemes, even digital modes. With only a single 2N3904 transistor,  [Jarno (PA3DMI)]’s tiny transmitter won’t do much more than send Morse using CW modulation, but given that it’s doing so from inside a walnut shell, we have no complaints. The two halves of the shell are hinged together and hold a scrap of perfboard for the simple quartz crystal oscillator. The prototype was tuned outside the shell,  and the 9-volt battery is obviously external, but aside from that it’s nothing but nuts.

We’d love to see [Jarno] add a spring to the hinge and contacts on the shell halves so no keyer is required. Who knows? Castanet-style keying might be all the rage with hams after that.

Continue reading “Ham Goes Nuts For Tiny Transmitter” →

Old Thermometer Gets New Eyes

February 24, 2017 by 14 Comments

As much as we’d like to have the right tools for the right job all of the time, sometimes our parts drawers have other things in mind. After all, what’s better than buying a new tool than building one yourself from things you had lying around? That’s at least what [Saulius] must have been thinking when he needed a thermometer with a digital output, but only had a dumb, but feature-rich, thermometer on hand.

Luckily, [Saulius] had a webcam lying around as well as an old thermometer, and since the thermometer had a LCD display it was relatively straightforward to get the camera to recognize the digits in the thermometer’s display. This isn’t any old thermometer, either. It’s a four-channel thermometer with good resolution and a number of other useful features (with an obvious lack of communications abilities), so it’s not something that he could just overlook.

Once the camera was mounted to an arm and pointed at the thermometer’s screen, an algorithm running on a computer detects polygons and reports its information into a CSV file. This process is made simpler by the fact that LCD screens like this are very predictable. From there, the data is imported into LibreOffice and various charts and graphs can be made.

Although perhaps not the most elegant of hacks, sometimes you have to work with the supplies that are on hand at the time. Sometimes the tools you need are too expensive, politically dangerous, or too impractical to obtain. To that end [Saulius]’s hack is a great example of what hacks are possible with the right mindset.