[Malebuffy] bought himself a used boat last year. Fuel isn’t exactly cheap where he lives, so he wanted a way to monitor his fuel consumption. He originally looked into purchasing a Flowscan off the shelf, but they were just too expensive. In the interest of saving money, [Malebuffy] decided to build his own version of the product instead.

To begin, [Malebuffy] knew he would need a way to display the fuel data once it was collected. His boat’s console didn’t have much room though, and cutting holes into his recently purchased boat didn’t sound like the best idea. He decided he could just use his smart phone to display the data instead. With that in mind, [Malebuffy] decided to use Bluetooth to transmit the data from the fuel sensors to his smart phone.

The system uses an older Arduino for the brain. The Arduino gets the fuel consumption readings from a Microstream OF05ZAT fuel flow sensor. The Arduino processes the data and then transmits it to a smart phone via a Bluetooth module. The whole circuit is powered from the boat battery using a DC adapter. The electronics are protected inside of a waterproof case.

[Malebuffy’s] custom Android apps are available for download from his website. He’s also made the Arduino code available in case any one wants to copy his design.

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!

Maker Faire Rome video interviews – “What have you built with Arduino?” – A couple of new protagonists for our short series:

• Zaho – Print your own megastructure – Controlled by Arduino
• Eco Floppy Robot – Robot controlled by Arduino

Explore playlist on Youtube >>

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[Brett] was looking for a way to improve on an old binary clock project from 1996. His original clock used green LEDs to denote between a one or a zero. If the LED was lit up, that indicated a one. The problem was that the LEDs were too dim to be able to read them accurately from afar. He’s been wanting to improve on his project using seven segment displays, but until recently it has been cost prohibitive.

[Brett] wanted his new project to use 24 seven segment displays. Three rows of eight displays. To build something like this from basic components would require the ability to switch many different LEDs for each of the seven segment displays. [Brett] instead decided to make things easier by using seven segment display modules available from Tindie. These modules each contain eight displays and are controllable via a single serial line.

The clock’s brain is an ATmega328 running Arduino. The controller keeps accurate time using a DCF77 receiver module and a DCF77 Arduino library. The clock comes with three display modes. [Brett] didn’t want and physical buttons on his beautiful new clock, so he opted to use remote control instead. The Arduino is connected to a 433MHz receiver, which came paired with a small remote. Now [Brett] can change display modes using a remote control.

A secondary monochrome LCD display is used to display debugging information. It displays the time and date in a more easily readable format, as well as time sync information, signal quality, and other useful information. The whole thing is housed in a sleek black case, giving it a professional look.

Read more on MAKE

Read more on MAKE

Maker Faire Rome video interviews – “What have you built with Arduino?” – A couple of new protagonists for our short series:

• Biopic Agriorto – Agricultural Plantation using Irduino / Arduino

• UniRoma 2 – Interview with automation engineering students using Arduino Due

Explore playlist on Youtube >>

We’ve always wondered why we have indoor plumbing if it isn’t hooked up to our coffee pots. We probably drink as much coffee as water anyway, so why not just hook up a water line to refill the pot? [Loose Cannon] aka [LC] has been working on just that problem, with a whole lot of extra features, creating a very robust automatically-filled, gravity-fed, vacuum-sealed water tank for whatever appliance you have that could use it, including your coffee pot.

[LC] tapped into the 1/4″ water line from the ice maker, which has the added bonus of being a common size for solenoid valves. He’s using an eTape sensor to measure the water level in the reservoir, but he ALSO is using a flow meter in the line itself to double-check that the reservoir won’t overflow. The flow meter allows a hard limit to be set for the maximum amount of water allowed into the tank. He’s used an Arduino Micro to tie the project together, which also handles a real-time clock so the tank can be filled on a schedule.

The tank that [LC] was trying to fill was vacuum-sealed as well, which made things a little trickier. Without a vacuum on the tank, the water would just run out of the overflow valve. This is an interesting project that goes way beyond the usual automatic water supplies for coffee pots we’ve seen before.

Read more on MAKE