Open Source Binary Wristwatch Is Professional Quality

If you want to proclaim to the world that you’re a geek, one good way to go about it is to wear a wristwatch that displays the time in binary. [Jordan] designs embedded systems, and he figured that by building this watch he could not only build up his geek cred but also learn a thing or two about working with PIC microcontrollers for low power applications. It seems he was able to accomplish both of these goals.

The wristwatch runs off of a PIC18F24J11 microcontroller. This chip seemed ideal because it included a built in real-time clock and calendar source. It also included enough pins to drive the LEDs without the need of a shift register. The icing on the cake was a deep sleep mode that would decrease the overall power consumption.

The watch contains three sets of LEDs to display the information. Two green LEDs get toggled back and forth to indicate to the user whether the time or date is being displayed. When the time is being displayed, the green LED toggles on or off each second. The top row of red LEDs displays either the current hour or month. The bottom row of blue LEDs displays the minutes or the day of the month. The PCB silk screen has labels that help the user identify what each LED is for.

The unit is controlled via two push buttons. The three primary modes are time, date, and seconds. “Seconds” mode changes the bottom row of LEDs so they update to show how many seconds have passed in the current minute. [Jordan] went so far as to include a sort of animation in between modes. Whenever the mode is changed, the LED values shift in from the left. Small things like that really take this project a step further than most.

The board includes a header to make it easy to reprogram the PIC. [Jordan] seized an opportunity to make extra use out of this header. By placing the header at the top of the board, and an extra header at the bottom, he was able to use a ribbon cable as the watch band. The cable is not used in normal operation, but it adds that extra bit of geekiness to an already geeky project.

[Jordan] got such a big response from the Internet community about this project that he started selling them online. The only problem is he sold out immediately. Luckily for us, he released all of the source code and schematics on GitHub so we can make our own.

Hacklet 37 – Nixie Projects

Nothing quite beats the warm glow of a tube. What better way to enjoy that glow than to use it to read numbers? Nixie tubes were created by Haydu Brothers Laboratories, and popularized by Burroughs Corp in 1955. The name comes from NIX I – or “Numeric Indicator eXperimental No. 1″. By the mid 1970’s, seven segment LED’s were becoming popular and low-cost alternatives to Nixies, but they didn’t have the same appeal. Nixie tubes were manufactured all the way into the 1990’s. There’s just something about that tube glow that hackers, makers, and humans in general love. This week’s Hacklet highlights the best Nixie (and Nixie inspired) projects on Hackaday.io!

temperatureDisplayWe start with [Sascha Grant] and Nixie Temperature Display. [Sascha] mixed an Arduino, a Dallas DS18B20 Temperature sensor, and three IN-12A Nixie tubes to create a simple three digit temperature display. We really love the understated laser-cut black acrylic case. An Arduino Pro Micro reads the Dallas 1-wire sensor and converts the temperature to BCD. High voltage duties are handled by a modular HV power supply which bumps 9V up to the required 170V.  Controlling the Nixie tubes themselves are the classic K155ID1 BCD to decimal converter chips – a favorite for clock builders.

 

driverNext up is [Christoph] with Reading Datasheets and Driving Nixie Tubes. Chips like the K155ID1, and the 74141 make driving Nixie tubes easy. They convert Binary Coded Decimal (BCD) to discrete outputs to drive the cathodes of the Nixie. More importantly, the output drivers of this chip are designed to handle the high voltages involved in driving Nixie tubes. These chips aren’t manufactured anymore though, and are becoming rare. [Christoph] used more common parts. His final drive transistor is a MPSA42 high voltage NPN unit. Driving the MPSA42’s is a 74HC595 style shift register. [Christoph] used a somewhat exotic Texas Instruments TPIC6B595 with FET outputs, but any shift register should work here. The project runs on a Stellaris Launchpad, so it should be Arduino compatible code.

fixietube[Davedarko] has the fixietube clock. Fixietube isn’t exactly a Nixie. It’s an LED based display inspired by Nixie tubes. Modern amber LEDs aren’t quite the same as classic Nixies, but they get pretty darn close. [Dave] designed a PCB with a 3×5 matrix of LEDs to display digits. A few blue LEDs add a bit of ambient light. The LEDs are driven with a 74HC595 shift register. The entire assembly mounts inside a tiny glass jam jar, giving it the effect of being a vacuum tube. The results speak for themselves – fixietubes certainly aren’t Nixies, but they look pretty darn good. Add a nice 3D printed case, and you’ve got a great project which is safe for anyone to build.

openNixieFinally, we have [Johnny.drazzi] with his Open Nixie Clock Display. [Johnny] has been working on Open Nixie for a few years. The goal is to create a Nixie based clock display which can be driven over the SPI bus. So far, [Johnny] has 6 Russian IN-12 tubes glowing with the help of the ubiquitous K155ID1 BCD to decimal converter. The colons of the clock are created with two INS-1 neon indicators. [Johnny] spends a lot of time analyzing the characteristics of a Nixie tube – including the strike voltage, and steady state current. If you’re interested in building a Nixie circuit yourself, his research is well worth a read!

Not satisfied? Want more Nixie goodness? Check out our Nixie tube project list!

That’s about all the time we have for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Laser-Cut Clock Uses Planetary Gear

[wyojustin] was trying to think of projects he could do that would take advantage of some of the fabrication tech that’s become available to the average hobbyist. Even though he doesn’t have any particular interest in clocks, [wyojustin] discovered that he could learn a lot about the tools he has access to by building a clock.

[wyojustin] first made a clock based off of a design by [Brian Wagner] that we featured a while back. The clock uses an idler wheel to move the hour ring so it doesn’t need a separate hour hand. After he built his first design, [wyojustin] realized he could add a planetary gear that could move an hour hand as well. After a bit of trial and error with gear ratios, he landed on a design that worked.

The clock’s movement is a stepper motor that’s driven by an Arduino. Although [wyojustin] isn’t too happy with the appearance of his electronics, the drive setup seems to work pretty well. Check out [wyojustin]’s site to see the other clock builds he’s done (including a version with a second hand), and you can peruse all of his design files on GitHub.

Looking for more clock-building inspiration? Check out some other awesome clock builds we’ve featured before.

A Kitchen Timer Fit for MacGyver

Here’s a project that you don’t want to bring into an airport, ship through the mail, or probably even remove from your home. [ProjectGeek] has built himself a simple kitchen timer masquerading as a bomb. The build is actually pretty simple, but the end result is something that would look at home in a Hollywood action flick.

The timer circuit is built from four simple components. An 8051 microcontroller board is used as the primary controller and timer. The code is available on GitHub. This board is attached to a another board containing four momentary push buttons. These are used to program the timer and to stop the buzzing. Another board containing four 7-segment displays is used to show the remaining time on the timer. A simple piezo buzzer is used to actually alert you when the timer has run out. All of these components are connected with colorful jumper wires.

The physical part of this build is made from easily available components. Old newspapers are rolled up to form the “explosive” sticks. These are then covered in plain brown paper ordinarily used to cover text books. The rolls are bundled together and fixed with electrical tape. The electronics can then be attached to the base with some hot glue or double-sided tape.

A Colorful Clock for Toddlers

[Don] and his wife were looking for a way to teach their two-year old daughter how to tell time. She understood the difference between day and night, but she wasn’t old enough to really comprehend telling the actual time. [Don’s] solution was to simplify the problem by breaking time down into colored chunks representing different tasks or activities. For example, if the clock is yellow that might indicate that it’s time to play. If it’s purple, then it’s time to clean up your room.

[Don] started with a small, battery operated $10 clock from a local retailer. The simple clock had a digital readout with some spare room inside the case for extra components. It was also heavy enough to stay put on the counter or on a shelf. Don opened up the clock and got to work with his Dremel to free up some extra space. He then added a ShiftBrite module as a back light. The ShiftBrite is a high-brightness LED module that is controllable via Serial. This allows [Don] to set the back light to any color he wants.

[Don] already had a Raspberry Pi running his DIY baby monitor, so he opted to just hijack the same device to control the ShiftBrite. [Don] started out using a Hive13 GitHub repo to control the LED, but he found that it wasn’t suitable for this project. He ended up forking the project and altering it. His alterations allow him to set specific colors and then exit the program by typing a single command into the command line.

The color of the ShiftBrite is changed according to a schedule defined in the system’s crontab. [Don] installed Minicron, which provides a nice web interface to make it more pleasant to alter the cron job’s on the system. Now [Don] can easily adjust his daughter’s schedule via web page as needed.

 

Whiteboard Clock Draws the Time

[Maurice] recently built a clock that draws the time (Google Doc) on a white board. We’ve seen plenty of clock hacks in the past, and even a very similar one. It’s always fun to see the different creative solutions people can come up with to solve the same problem.

This device runs on a PIC16F1454 microcontroller. The code for the project is available on GitHub. The micro is also connected to a 433MHz receiver. This allows a PC to keep track of the time, instead of having to include a real-time clock in the circuit. The USB connector is only used for power. All of the mounting pieces were designed in OpenSCAD and printed on a 3D printer. Two servos control the drawing arms. A third servo can raise and lower the marker to the whiteboard. This also has the added benefit of being able to place the marker tip inside of an eraser head. That way the same two servos can also erase the writing.

The communication protocol for this systems is interesting. The transmitter shows up on [Maurice’s] PC as a modem. All he needs to do to update the time is “echo 12:00 > /dev/whiteboard”. In this case, the command is run by a cron job every 5 minutes. This makes it easy to tweak the rate at which the time updates on the whiteboard. All communication is done one-way. The drawing circuit will verify the checksum each time it receives a message. If the check fails, the circuit simply waits for another message. The computer transmits the message multiple times, just in case there is a problem during transmission.

Hat-Mounted Clock Requires Mirror For Wearer To Tell Time

[gfish] was planning on attending Burning Man and wanted to make something unique (and useful) to wear. He decided on a hat/clock hybrid. Just slapping a clock on a hat would be too easy, though. [gfish] wanted his hat to change time zones both via manual switches or physical location.

On the front of the hat there are 2 hands, as most clocks have. Each one is attached to one of two concentric shafts that run to the back of the hat. Each hand is individually controlled by an RC vehicle servo. Those of you familiar with RC servos know that a servos’ max rotation is about 180 degrees and is certainly not enough for a full revolution required by the clock. To fix this, there is a 3:1 gear set that allows a 120 degree rotation of the servo to move the clock hand a full 360 degrees. With this method, each hand can’t move past 12 and instead has to quickly move counter-clockwise to get where it needs to be in order to again start its journey around the clock face.

Mounted inside the hat there is an Arduino that controls the clock, a GPS shield to determine location and an RTC to maintain accurate time. Mounted on the side of the hat is a control panel that contains an overall on/off switch as well as a rotary switch for selecting a specific timezone or for engaging GPS mode. The whole thing is powered by a 9 volt battery.

If you like unnecessarily complicated top hats, check out this WiFi enabled message displaying one.

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