Newly minted hams like me generally find themselves asking, “What now?” after getting their tickets. Amateur radio has a lot of different sub-disciplines, ranging from volunteering for public service gigs to contesting, the closest thing the hobby has to a full-contact sport. But as I explore my options in the world of ham radio, I keep coming back to the one discipline that seems like the purest technical expression of the art and science of radio communication – low-power operation, or what’s known to hams as QRP. With QRP you can literally talk with someone across the planet on less power than it takes to run a night-light using a radio you built in an Altoids tin. Now that’s a challenge I can sink my teeth into.
[Jim Merullo] and his son were enjoying a nice game of Frisbee when an unfortunate dive led to an injury. His son broke his pinky finger leaving doctors no choice other than bounding his entire left hand in an unreasonably large cast. For most, this would mean no use of the left hand for several weeks, which is somewhat problematic if your son has a Minecraft addiction. [Jim], however, is no stranger to the hacker community and began working on a solution. He broke out the #2 Philips screwdriver, fired up the soldering iron and got to work.
A detailed analysis of the injured left hand revealed limited use of the middle and ring finger, and full use of the thumb. Because his son played the game using his right hand for the mouse and left for the keyboard, he needed to find a way for him to operate a keyboard with the limited use of his left hand. He took apart an old USB keyboard and soldered up some tactile switches to emulate the needed key presses. After making a fashionable Altoids tin mount that fit over the cast, his son was able to enjoy his favorite video game with limited interruption.
Altoids – they’ve been around since King George III was on the throne. These curiously strong mints have had a storied history, a copy of which is included in every tin. They taste pretty good, but most hackers and makers are more interested in the pocket-sized tin than the mints themselves. It may have been the ham radio operators who first used Altoids tins to hold their sensitive transmitter and receiver circuits. The metal case makes a perfect electromagnetic field shield. It wasn’t long before the tins found their way into thousands of projects. This week’s Hacklet features some of the best projects with Altoids (and other mint) tins on Hackaday.io!
We start with [Chad Lawson] and the Networking Group Timing Light. [Chad] has a networking meeting where each member has two minutes to introduce themselves. As is the case with most meetings, people tend to be a bit long-winded, running well beyond their allotted two minutes. The timing light contains an RGB LED which changes from green to yellow to red as a speaker’s time ticks away. The timer is reset by simply tilting the mint tin. [Chad] is hoping that the timer will serve as a gentle reminder to keep everyone on track time-wise.
Next up is [Rjpope42] and his AM/FM Transmitter Pair. [Rjpope42] loves vintage tube radios, and wants to send his own signals to his amber glowing projects. Wiring an external audio input to a tube radio is pretty easy, but nothing beats a simple AM transmitter for convenience. Small FM transmitters are commonly available to add an MP3 player input to cars without an AUX audio in, but their AM counterparts have become rare. [Rjpope42] has built AM and FM transmitters, each of which will fit in a Mint Tin case. The AM transmitter can run on 9V or 12V, and even includes a USB power output for charging an MP3 player or phone!
[John Hamann] entered Distance Analyzer 3000 in the Trinket EDC contest. While he didn’t win, it was still a great project, especially since this is [John’s] first serious Arduino project. The idea is to use a rotary encoder with a wheel to measure distances. Think of it like a mini version of a surveyor’s walking wheel. The Pro Trinket counts the pulses from the rotary encoder, then converts this to a distance in feet. We’d love to see [John] continue on the project. An ultrasonic distance sensor would be a great addition for multi-sensor distance reads!
Finally, we have [colonwq] with TTTOTP, a pro trinket Time based One Time Password (TOTP) generator. [colonwq] used the trinket to implement the well-known time based one time password algorithm. To implement a project like this, you need a stable time source. The ATmega328 isn’t very good at this, so [colonwq] used a Dallas DS1307 clock chip to keep track of things. The actual code is displayed on a 4 digit 7 segment display. When the button is pressed, the first half of the code is displayed. Once the button is released, the second half of the code is displayed for several seconds.
Need more mint? Check out our curiously awesome mint tin project list!
Hackaday.io Update and MeArm Giveaway
Hackaday.io has a few new features, including @username and #projectID. If you mention someone’s username with an @ in front of it, that user will get a notification in their stack. The same goes with mentioning a project ID with a # up front. To celebrate this, we’re giving away a pair of special edition MeArms. All you have to do is leave a comment using the features on this project log. Huge thanks to [Jasmine] for setting all this up, and to [Ben] for letting us hijack his project for the week!
That’s it for this Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!
Extensive research shows that tobacco kills. This is common knowledge as of late, which has prompted a flurry of anti-smoking ads to flood in. Regular smokers are now reconsidering their smoking patterns and are looking at healthier alternatives. Among those options are electronic cigarettes that vaporize flavorful liquid into smooth drags of smoke.
Prices for these devices can range anywhere from $40 to $240, which can be quite expensive for those on a budget. So instead of buying one, [MrRedBeard] decided to create his own DIY electronic cigarette contraption out of an Altoids can.
The approximate cost (not including batteries) is about $12. This covers the 5 Amp adjustable voltage regulator and the 500 ohm potentiometer that is best used for a rig like this. The wattage is what drives the heat giving it a more consistent vapor stream of cloud smoke.
DSLRs aside, the price of digital cameras these days can make it easy to consider just tossing your old one out when it breaks. [Leonidas Tolias] had another idea, and with a few broken cameras he had on hand he constructed a slick little pocket-sized projector.
The project started out as a pair of lenses from busted cameras and an Altoids tin in which he mounted them. The larger lens from a video camera was installed on the exterior of the tin, while the smaller of the two was mounted inside. Bits from disposable cameras were used to create a set of film reels, which he supports with some hand cut scrap aluminum. He made some test photo slides by printing some images on transparency paper, which he can cycle through using a film advancement rig he built out of string and a couple of gears.
While you won’t be using this projector for your next boring PowerPoint presentation, it does work pretty well as you can see in pictures on [Leonidas’] site.
[linux-dude] always wanted to have a binary clock, but he didn’t want to pay someone else to make it for him. Additionally, he was looking for a compact alarm clock he could take on the road, rather than relying on the one in his hotel room.
Inspired by other binary clock projects he has seen over the years, he set off to build his own, which he wanted to fit inside an Altoids tin. His binary clock uses an Arduino Duemilanove (which fits perfectly in the tin) to keep time and control the indicator LEDs. The LEDs are arranged in two rows as you would expect, representing hours and minutes. A small piezo speaker serves as the alarm buzzer, which should be sufficient to wake up most people, though something bigger might be required for heavy sleepers.
We didn’t see any sort of battery pack or power plug mentioned, so we’re not quite sure how [linux-dude] keeps his clock juiced up. Additionally, the lack of an real time clock is something we’re puzzled by. While the Arduino does have a clock function that can be used, an RTC might serve him better – then again if he’s gone for just a day or two at a time, a small amount of drift may not be an issue.