When it comes to educational electronic projects, it’s hard to go past building a clock. You learn tons about everything from circuit concepts and assembly skills to insights about the very nature of time itself. And you get a clock at the end of it! [hamblin.joe] wanted to do a simple project for kids along these lines, so whipped up a neat design using analog meters to display the time.
The build relies on that old stalwart, the Arduino Uno, to run the show. It’s hooked up to a DS3231 real-time clock module so it can keep accurate time for long periods, as is befitting a clock. Displaying the time is done via the use of two analog meters, each fitted with a custom backing card. One displays hours, the other, minutes. The analog meters are simply driven by the PWM outputs of the Arduino.
It’s not a hugely complex project, but it teaches so much. It provides an opportunity to educate the builders about real-time clocks, microcontroller programming, and even the concepts behind pulse width modulation. To say nothing of the physical skills, like learning to solder or how to assemble the laser-cut enclosure. Ultimately, it looks like a really great way for [hamblin.joe] and his students to dive into the world of modern electronics.
[Build Some Stuff] created an unusual spiral clock that’s almost entirely made from laser-cut wood, even the curved and bendy parts.
The living hinge is one thing, but getting the spacing, gearing, and numbers right also takes work.
The clock works by using a stepper motor and gear to rotate the clock’s face, which consists of a large dial with a spiral structure. Upon this spiral ramp rolls a ball, whose position relative to the printed numbers indicates the time. Each number is an hour, so if the ball is halfway between six and seven, it’s 6:30. At the center of the spiral is a hole, which drops the ball back down to the twelve at the beginning of the spiral so the cycle can repeat.
The video (embedded below) demonstrates the design elements and construction of the clock in greater detail, and of particular interest is how the curved wall of the spiral structure consists of a big living hinge, a way to allow mostly rigid materials to flex far beyond what they are used to. Laser cutting is well-suited to creating living hinges, but it’s a technique applicable to 3D printing, as well.
In retrocomputing circles, it’s often the case that the weirder and rarer the machine, the more likely it is to attract attention. And machines don’t get much weirder than the DEC Rainbow 100-B, sporting as it does both Z80 and 8088 microprocessors and usable as either a VT100 terminal or as a PC with either CP/M or MS-DOS. But hey — at least it got the plain beige box look right.
Weird or not, all computers have at least a few things in common, a fact which helped [Dr. Joshua Reichard] home in on the problem with a Rainbow that was dead on arrival. After a full recapping — a prudent move given the four decades since the machine was manufactured — the machine failed to show any signs of life. The usual low-hanging diagnostic fruit didn’t provide much help, as both the Z80 and 8088 CPUs seemed to be fine. It was then that [Joshua] decided to look at the heartbeat of the machine — the 24-ish MHz clock shared between the two processors — and found that it was flatlined.
Unwilling to wait for a replacement, [Joshua] cobbled together a temporary clock from an Arduino Uno and an Si5351 clock generator. He connected the output of the card to the main board, whipped up a little code to generate the right frequency, and the nearly departed machine sprang back to life. [Dr. Reichard] characterizes this as a “defibrillation” of the Rainbow, and while one hates to argue with a doctor — OK, that’s a lie; we push back on doctors all the time — we’d say the closer medical analogy is that of fitting a temporary pacemaker while waiting for a suitable donor for a transplant.
This is the second recent appearance of the Rainbow on these pages — [David] over at Usagi Electric has been working on the graphics on his Rainbow lately.
You have to be pretty ambitious to modify a clock to run for 50 years on a single battery. You also should probably be pretty young if you think you’re going to verify your power estimates, at least in person. According to [Josh EJ], this modified quartz analog clock, which ticks off the date rather than the time, is one of those “The March of Time” projects that’s intended to terrify incentivize you by showing how much of the year is left.
Making a regular clock movement slow down so that what normally takes an hour takes a month without making any mechanical changes requires some clever hacks. [Josh] decided to use an Arduino to send digital pulses to the quartz movement to advance the minute hand, rather than let it run free. Two pulses a day would be perfect for making a 30-day month fit into a 60-minute hour, but that only works for four months out of the year. [Josh]’s solution was to mark the first 28 even-numbered minutes, cram 29, 30, and 31 into the last four minutes of the hour, and sort the details out in code.
As for the low-power mods, there’s some cool wizardry involved with that, like flashing the Arduino Pro Mini with a new bootloader that reduces the clock speed to 1 MHz. This allows the microcontroller and RTC module to run from the clock movement’s 1.5 V AA battery. [Josh] estimates a current draw of about 6 μA per day, which works out to about 50 years from a single cell. That’s to be taken with a huge grain of salt, of course, but we expect the battery will last a long, long time.
[Josh] built this clock as part of the Low-Power Challenge contest, which wrapped up this week. We’re looking forward to the results of the contest — good luck to all the entrants!
For those unfamiliar with the details of the expansive work of fiction of Harry Potter, it did introduce a few ideas that have really stuck in the collective conscious. Besides containing one of the few instances of time travel done properly and introducing a fairly comprehensive magical physics system, the one thing specifically that seems to have had the most impact around here is the Weasley family clock, which shows the location of several of the characters. We’ve seen these built before in non-magical ways, but this latest build seeks to drop the price tag on one substantially.
To do this, the build relies on several low-cost cloud computing solutions and smartphone apps to solve the location-finding problem. The app is called OwnTracks and is an open-source location tracker which can report data to any of a number of services. [Simon] sends the MQTT data to a cloud-based solution called HiveMQCloud, but you could send it anywhere in principle. With the location tracking handled, he turns to some very low-cost Arduinos to control the stepper motors which point the clock hands to the correct locations on the face.
While the build does rely on a 3D printer for some of the internal workings of the clock, this does bring the cost down substantially when compared to other options. Especially when compared to this Weasley family clock which was built into a much larger piece of timekeeping equipment, having an option for a lower-cost location-tracking clock face like this one is certainly welcome.
Anyone can buy a clock, but building your own lets you express your creative flair along the way. [Edison Science Corner] did just that with this neat sci-fi looking design.
The build relies on an Arduino Pro Mini to run the show, paired with a DS3231 real-time clock module. The latter part is of great importance, as without it, the Arduino would not keep accurate time. The 3D printed enclosure looks nondescript from the outside. However, inside, it’s got a neat triangular structure which allows the time to be displayed in that attractive tessellated triangular fashion. There’s a black plastic separator between all the segments which stop unattractive bleed-through and really help with the final effect. The individual triangles are each lit by a NeoPixel LED, which are both addressable and capable of lighting up in RGB colors. It makes for an attractive and colorful display.
This is a rewrite of a project I created in 2010 which brought me a lot of joy, so I hope you enjoy it too.Please read the entire article before starting your own. You can still make it today, the parts are easily available.
I’ve always enjoyed making Arduino-powered clocks, however over time they tended to become increasingly complex. So to counter this, allow me to introduce you to “Blinky” the one-eyed clock:
It reminds me of the giant killer orb “Rover” from “The Prisoner“… Using a minimal Arduino bootrom system, a DS1307 real time clock IC and an RGB diffused LED, you can make a clock that blinks the time, using the colours of the LED to note different numerical values.
For example, if the time is 12:45, the clock will blink red 12 times, then show blue for a second (think of this as the colon on a digital clock) then blink four times in green (for forty minutes), then blink three times in red for the individual minutes.
If there is a zero, blink blue quickly. Then the clock will not display anything for around forty seconds, then repeat the process. Here he (she, it?) is blinking the time:
Setting the clock is simple. It is set to start at 12:00 upon power up. So for the first use you have to wait until about five seconds before midday or midnight, then power it up. To save cost it doesn’t use a backup lithium battery on the real-time clock IC, but you could add one if required. So let’s get started.
The first thing to do was test the RGB LED for brightness levels, so I just connected it to the digital output pins of my Arduino-compatible board via suitable current-limiting resistors. Red, green and blue to D9, D10 and D11 respectively. Each LED is going to be different, so to ensure maximum brightness without causing any damage you need to calculate the appropriate resistor values.
This is quite easy, the formula is: resistor (ohms) = voltage drop / LED current So if you have a 5V supply, and LED that needs only 2 volts, and draws 20 milliamps (0.2 amps) , the calculation will be: resistor = (5-2)/0.02 = 150 ohms. To be safe I used 180 ohm resistors. The LED was tested with this simple sketch:
/*
blinky LED test
*/
int red = 2;
int green = 3;
int blue = 4;
int d = 300;
void setup()
{
pinMode(red, OUTPUT);
pinMode(green, OUTPUT);
pinMode(blue, OUTPUT);
}
void loop()
{
digitalWrite(red, HIGH);
delay(d);
digitalWrite(red, LOW);
delay(d);
digitalWrite(green, HIGH);
delay(d);
digitalWrite(green, LOW);
delay(d);
digitalWrite(blue, HIGH);
delay(d);
digitalWrite(blue, LOW);
delay(d);
}
It was interesting to alter the value of d, the delay variable, to get an idea for an appropriate blinking speed. Originally the plan was to have the LED in a photo frame, but it was decided to mount a ping-pong ball over the LED for a retro-style look. Here is a short video of the result of the test:
If you are going to use a ping-pong ball, please be careful when cutting into it with a knife, initially it may require a lot of force, but once the knife cuts through it does so very quickly.
Now it was time to develop the sketch to convert time into blinks. The sketch itself is quite simple. Read the hours and minutes from the DS1307 timer IC; convert the hours to 12 hour time; then blink an LED for the number of hours, display another colour for the colon; divide the minutes by ten and blink that in another colour; then the modulus of minutes and ten to find the individual minutes, and blink those out. Here is the first test sketch:
/*
"blinky" the one-eyed clock
Version beta 1
John Boxall August 2010/6th April 2022 - http://tronixstuff.com
DS1307/i2c timekeeping based on code by Maurice Ribble 17-4-2008 - http://www.glacialwanderer.com/hobbyrobotics
*/
#include "Wire.h"
#define DS1307_I2C_ADDRESS 0x68
int red = 9; // LEDs connected to these pins as you might want to PWM them to alter brightness
int green = 10;
int blue = 11;
// Convert normal decimal numbers to binary coded decimal
byte decToBcd(byte val)
{
return ( (val / 10 * 16) + (val % 10) );
}
// Convert binary coded decimal to normal decimal numbers
byte bcdToDec(byte val)
{
return ( (val / 16 * 10) + (val % 16) );
}
void setDateDs1307(byte second, // 0-59
byte minute, // 0-59
byte hour, // 1-23
byte dayOfWeek, // 1-7
byte dayOfMonth, // 1-28/29/30/31
byte month, // 1-12
byte year) // 0-99
{
Wire.beginTransmission(DS1307_I2C_ADDRESS);
Wire.write(0);
Wire.write(decToBcd(second)); // 0 to bit 7 starts the clock
Wire.write(decToBcd(minute));
Wire.write(decToBcd(hour));
Wire.write(decToBcd(dayOfWeek));
Wire.write(decToBcd(dayOfMonth));
Wire.write(decToBcd(month));
Wire.write(decToBcd(year));
Wire.write(0x10); // sends 0x10 (hex) 00010000 (binary) to control register - turns on square wave
Wire.endTransmission();
}
void getDateDs1307(byte *second,
byte *minute,
byte *hour,
byte *dayOfWeek,
byte *dayOfMonth,
byte *month,
byte *year)
{
// Reset the register pointer
Wire.beginTransmission(DS1307_I2C_ADDRESS);
Wire.write(0);
Wire.endTransmission();
Wire.requestFrom(DS1307_I2C_ADDRESS, 7);
*second = bcdToDec(Wire.read() & 0x7f);
*minute = bcdToDec(Wire.read());
*hour = bcdToDec(Wire.read() & 0x3f); // Need to change this if 12 hour am/pm
*dayOfWeek = bcdToDec(Wire.read());
*dayOfMonth = bcdToDec(Wire.read());
*month = bcdToDec(Wire.read());
*year = bcdToDec(Wire.read());
}
void blinkLED(int colour, int ondelay, int offdelay, int blinks)
// blinks LED on pin 'colour' for 'blinks' times with on and off delay of 'ondelay', 'offdelay'
// colour: 9 is red, 10 is green, 11 is blue
{
for (int a = 0; a < blinks; a++) {
digitalWrite(colour, HIGH); delay(ondelay); digitalWrite(colour, LOW); delay(offdelay);
}
}
void blinkTime() // blinks the time
{
byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
float aa;
int bb;
getDateDs1307(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, &year);
// convert hours from 24 to 12 hour time
if (hour == 0)
{
hour = 12;
}
if (hour > 12)
{
hour = hour - 12;
}
blinkLED(9, 500, 500, hour); // blink hours in red
blinkLED(11, 1000, 500, 1); // show blue for one second
aa = minute;
aa = aa / 10;
bb = int(aa); // find the value of tens of minutes (0~5)
if (bb > 0)
{
blinkLED(10, 500, 500, bb); // blink tens of minutes
}
if (bb == 0) // but if the time is something like 03:02?
{
blinkLED(11, 200, 200, 1); // blink blue quickly for zero
}
aa = minute % 10; // find modulo of minutes to get single minutes
if (bb > 0)
{
blinkLED(9, 500, 500, bb);
}
if (bb == 0)
{
blinkLED(11, 200, 200, 1); // blink blue quickly for zero
}
}
void setup()
{
byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
Wire.begin();
second = 0;
minute = 17;
hour = 4;
dayOfWeek = 6; // these values are moot, but need to store something
dayOfMonth = 28;
month = 5;
year = 10;
setDateDs1307(second, minute, hour, dayOfWeek, dayOfMonth, month, year);
pinMode(red, OUTPUT);
pinMode(green, OUTPUT);
pinMode(blue, OUTPUT);
}
void loop()
{
blinkTime();
delay(5000);
}
Finally, the code was tested using the Arduino-compatible board and my home-made DS1307 real time clock shield (hey it was 2010, DS32xx were expensive). It is best to use existing hardware while testing, before committing to purchasing new hardware and so on. So here it is on the breadboard:
Here is the prototype in action:
If you’re wondering why the videos are potato-cam quality, smartphones couldn’t record using 4K Ultra HD in 2010.
But perhaps the first version was a little bland. By using analogWrite() we can control the brightness of the LED segments. So I’ve added two more functions, whiteGlow() and blueGlow(); whose purpose is to make the display “glow” by increasing then decreasing the brightness.
And I’ve scaled back the amount of blinking, to make blinky less obvious. So now the display will glow white to announce the forthcoming display of time, wait a second, blink the time (with a blue glowing colon) then stay dark for ten seconds before repeating the process. Here is a quick demonstration of this display style:
Here is the sketch for the above demonstration, and the final one I will use with the hardware prototype:
/*
"blinky" the one-eyed clock - Version 2.1
John Boxall 04 August 2010/6th April 2022
IDGAF licence
DS1307/i2c timekeeping based on code by Maurice Ribble
17-4-2008 - http://www.glacialwanderer.com/hobbyrobotics
*/
#include "Wire.h"
#define DS1307_I2C_ADDRESS 0x68
int red = 9; // LEDs connected to these pins as you might want to PWM them to alter brightness
int green = 10;
int blue = 11;
// Convert normal decimal numbers to binary coded decimal
byte decToBcd(byte val)
{
return ( (val / 10 * 16) + (val % 10) );
}
// Convert binary coded decimal to normal decimal numbers
byte bcdToDec(byte val)
{
return ( (val / 16 * 10) + (val % 16) );
}
void setDateDs1307(byte second, // 0-59
byte minute, // 0-59
byte hour, // 1-23
byte dayOfWeek, // 1-7
byte dayOfMonth, // 1-28/29/30/31
byte month, // 1-12
byte year) // 0-99
{
Wire.beginTransmission(DS1307_I2C_ADDRESS);
Wire.write(0);
Wire.write(decToBcd(second)); // 0 to bit 7 starts the clock
Wire.write(decToBcd(minute));
Wire.write(decToBcd(hour));
Wire.write(decToBcd(dayOfWeek));
Wire.write(decToBcd(dayOfMonth));
Wire.write(decToBcd(month));
Wire.write(decToBcd(year));
Wire.write(0x10); // sends 0x10 (hex) 00010000 (binary) to control register - turns on square wave
Wire.endTransmission();
}
void getDateDs1307(byte *second,
byte *minute,
byte *hour,
byte *dayOfWeek,
byte *dayOfMonth,
byte *month,
byte *year)
{
// Reset the register pointer
Wire.beginTransmission(DS1307_I2C_ADDRESS);
Wire.write(0);
Wire.endTransmission();
Wire.requestFrom(DS1307_I2C_ADDRESS, 7);
*second = bcdToDec(Wire.read() & 0x7f);
*minute = bcdToDec(Wire.read());
*hour = bcdToDec(Wire.read() & 0x3f); // Need to change this if 12 hour am/pm
*dayOfWeek = bcdToDec(Wire.read());
*dayOfMonth = bcdToDec(Wire.read());
*month = bcdToDec(Wire.read());
*year = bcdToDec(Wire.read());
}
void blinkLED(int colour, int ondelay, int offdelay, int blinks)
// blinks LED on pin 'colour' for 'blinks' times with on and off delay of 'ondelay', 'offdelay'
// colour: 9 is red, 10 is green, 11 is blue
{
for (int a = 0; a < blinks; a++)
{
digitalWrite(colour, HIGH);
delay(ondelay);
digitalWrite(colour, LOW);
delay(offdelay);
}
}
void blinkTime()
// blinks the time
{
byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
float aa;
int bb;
getDateDs1307(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, &year);
// convert hours from 24 to 12 hour time
if (hour == 0)
{
hour = 12;
}
if (hour > 12)
{
hour = hour - 12;
}
blinkLED(9, 500, 500, hour); // blink hours in red
blueGlow(1, 10);
aa = minute;
aa = aa / 10;
bb = int(aa); // find the value of tens of minutes (0~5)
if (bb > 0)
{
blinkLED(10, 500, 500, bb); // blink tens of minutes
}
if (bb == 0) // but if the time is something like 03:02?
{
blinkLED(11, 200, 200, 1); // blink blue quickly for zero
}
aa = minute % 10; // find modulo of minutes to get single minutes
bb = aa;
if (bb > 0)
{
blinkLED(9, 500, 500, bb); // blink tens of minutes
}
if (bb == 0)
{
blinkLED(11, 200, 200, 1); // blink blue quickly for zero
}
}
void whiteGlow(int n, int d)
{
for (int nn = 0; nn < n; nn++)
{
for (int a = 0; a <= 255; a++)
{
analogWrite(red, a);
analogWrite(green, a);
analogWrite(blue, a);
delay(d);
}
for (int a = 255; a >= 0; --a)
{
analogWrite(red, a);
analogWrite(green, a);
analogWrite(blue, a);
delay(d);
}
}
}
void blueGlow(int n, int d)
{
for (int nn = 0; nn < n; nn++)
{
for (int a = 0; a <= 255; a++)
{
analogWrite(blue, a);
delay(d);
}
for (int a = 255; a >= 0; --a)
{
analogWrite(blue, a);
delay(d);
}
}
}
void setup()
{
byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
Wire.begin();
second = 0;
minute = 17;
hour = 4;
dayOfWeek = 6; // these values are moot, but need to store something
dayOfMonth = 28;
month = 5;
year = 10;
setDateDs1307(second, minute, hour, dayOfWeek, dayOfMonth, month, year); // every time blinky has new batteries, it will start from midnight/midday
pinMode(red, OUTPUT);
pinMode(green, OUTPUT);
pinMode(blue, OUTPUT);
}
void loop()
{
whiteGlow(1, 10); // glow white - announces that the time will now be shown
delay(1000); // give people a second to focus on blinky
blinkTime();
delay(50000); // wait 50 seconds
}
Once happy with the sketch, I put a fresh ATmega328P-PU with Arduino bootloader in the board and programmed it with the sketch, to be used in the final version. The next step is to build my own hardware. The last hardware unknown is the amount of current the circuit draws. Once I know this the correct voltage regulator and power supply can be decided upon.
I had a fair idea it would be less than 100 milliamps, so I put a 6V battery onto supply duty via a 78L05 5V regulator (data sheet), and recorded the result:
So it varies, between 20.5 and 46 mA. As it only reaches 46 mA for a short time, we could consider the constant draw to be averaged out at 30 mA. I really want this to be able to run from a battery, but without having an external lead-acid battery lurking around, it will need a plug-pack with an output voltage greater than 7V DC.
Another alternative would be to run it from a USB socket, a nice source of 5V. If doing so, there wouldn’t be a need for the 78L05 regulator. Which brings us to the circuit diagram, which includes the power regulator. I’ve also altered the resistors to suit the RGB LED used, your values may be different:
And since it’s 2022, not 2010 – I’ve replaced the DS1307 circuit with a RTC module. Y1 is a three pin 16MHz ceramic resonator, we used those in 2010 as they were cheaper and easier than a crystal and two 22pF capacitors.
The circuit does not allow for uploading code, so you will need to program the microcontroller on another Arduino or compatible board, then transfer it to the blinky circuit board as described above. At this stage you should test it again – but using a solderless breadboard. In doing so you can make final hardware checks, and generally make sure everything works as it should. This is also a good stage to double-check you are happy with the display behaviour, default time and so on.
Used the Duemilanove as a lazy 5V for testing.
Time to solder up the circuit on some stripboard. Blank stripboard varies, but luckily I found this and a nice box to hold it in:
Stripboard does vary between retailers and so on, so you will need to work out the layout with your own board. In doing so, please double-check your work – follow the layout against the schematic and so on.
Have a break, then check it again. There is nothing worse than soldering away to realise you are one strip too far over or something. My hand-eye coordination is not the best, therefore my soldering isn’t pretty, but it works:
Note that the images above are using the 2010 circuit – which had a DS1307 sub-circuit.
One would say that there is a good argument for making your own PCBs… and I would agree with that. In 2010 it wasn’t that easy or inexpensive. Now you have KiCAD and Chinese PCB fabs tripping over themselves to give you cheap boards.
The LED is soldered to some short leads to give it a bit of play, and some heatshrink over the legs to keep them isolated:
And finally, to add a DC socket to feed blinky some power:
The last thing was to check the soldering once more under natural light, to check for bridges or shorts, then have a cup of tea. Upon my return I drilled out a hole in the enclosure lid for the LED, and one one the side for the DC socket, and fitted the lot together… and success! It worked.
I hope you enjoyed making this or at least reading about it. If you find this sort of thing interesting, please consider ordering one or both of my books from No Starch Press, or other book sellers:
Back in the old days, we didn’t have fancy digital clocks. No, we had good analog clocks with a big hand and a little hand, and if you wanted to know the time you had to look at the clock and figure out which number each hand was pointing at, or kind of pointing at. It wasn’t easy, and we liked it that way.
So now, along comes an analog clock that’s nothing but the hands — no dial, no numbers, just hands. How is such a thing possible? The clue is in the clock’s name: AKUROBATTO, and in the video below, which shows the acrobatic movements of the clock’s hands as it does its thing. Serial improbable-clock maker [ekaggrat singh kalsi] clearly put a lot of thought into this mechanism, which consists of the hands and a separate base. The hands are joined together at one end and powered by small stepper motors. The base has two docking areas, where servo-driven claws can grasp the hand assembly, either at the center pivot or at the tip of either hand. With a little bit of shuffling around at transition points, the hands sweep out the hours and minutes in a surprisingly readable way.
For as cool as the design of AKUROBATTO is, the internals are really something else. There are custom-built slip rings to send power to the motors and the Arduinos controlling them, sensors to determine the position of each hand, and custom gearboxes for the steppers. And the locking mechanisms on the base are worth studying too — getting that right couldn’t have been easy.
All in all, an impressive build. Whether displaying the time on a phosphorescent screen or a field of sequins, it seems like [ekaggrat] has a thing for unique clocks.
Electric utilities across the world have been transitioning their meters from the induction analog style with a distinctive spinning disc to digital “smart” meters which aren’t as aesthetically pleasing but do have a lot of benefits for utilities and customers alike. For one, meter readers don’t need to visit each meter every month because they are all networked together and can download usage data remotely. For another, it means a lot of analog meters are now available for projects such as this clock from [Monta].
The analog meters worked by passing any electricity used through a small induction motor which spun at a rate proportional to the amount of energy passing through it. This small motor spun a set of dials via gearing in order to keep track of the energy usage in the home or business. To run the clock, [Monta] connected a stepper motor with a custom transmission to those dials for the clock face because it wasn’t possible to spin the induction motor fast enough to drive the dials. An Arduino controls that stepper motor, but can’t simply drive the system in a linear fashion because it needs to skip a large portion of the “minutes” dials every hour. A similar problem arises for the “hours” dials, but a little bit of extra code solves this problem as well.
Once the actual clock is finished, [Monta] put some finishing touches on it such as backlighting in the glass cover and a second motor to spin the induction motor wheel to make the meter look like it’s running. It’s a well-polished build that makes excellent use of some antique hardware, much like one of his other builds we’ve seen which draws its power from a Stirling engine.
We around the Hackaday shop never get tired of seeing new ways to mark the passage of time. Hackers come up with all manner of interesting timekeeping modalities using every imaginable material and method of moving the mechanism once per whatever minimum time unit the hacker chooses to mark.
But honestly, there are only so many ways to make a clock, and while we’re bound to see some repeats, it’s still nice to go over old ground with a fresh approach. Take this linear sliding stencil clock for instance. [Luuk Esselbrugge] has included some cool design elements that bear a closer look. The video below shows that the display is made up of four separate stepper motors, each driving a vertical stencil via a rack-and-pinion mechanism. There a simple microswitch for homing the display, and a Neopixel for lighting things up.
The video below shows that the stencils move very, very slowly; [Luuk] says that this is to keep the steppers as quiet as possible. Still, this means that some time changes take more than a minute to accomplish, which is a minor problem. The Neopixel also doesn’t quite light up just one digit, which should be a pretty easy fix for version 2. Still, even with these issues, we like the stately movements of this clock, and appreciate [Luuk]’s attempts to make it easier to live with.
Don’t let the number of clocks you see on these pages dissuade you from trying something new, or from putting your twist on an old design. Start with fridge magnets, an old oscilloscope, or even a bevy of steel balls, and let your imagination run wild. Just make sure to tell us all about it when you’re done.
