Posts | Comments

Planet Arduino

Archive for the ‘clock’ Category

For Game of Thrones fans, it’s an awkward time. The show has ended its run on HBO (not without a certain level of controversy), the planned prequel is still years away, and who knows when George R. R. Martin will actually get around to writing the final books in the series. Fans have no choice but to entertain themselves while waiting for further tales of adventure from Westeros, which is how we get things like this motorized clock from [Techarge].

Inspired by the now iconic opening sequence from the HBO series, elements of the 3D printed model spin around while the theme song is played courtesy of a DFPlayer Mini MP3 player module and small 2 watt speaker. The audio hardware, motor, and four digit LED display module in the front are all connected to an Arduino with a custom PCB shield, giving the inside of the clock a very clean and professional appearance.

Around the back side [Techarge] has two small push buttons to set the hour and minutes, and a large toggle to control the music and movement. As of right now it needs to be switched on and off manually, but a future enhancement could see it kick on hourly.  We’d also like to see an RTC module added to the PCB, or better yet, switch over to the ESP8266 and just pull the time down from NTP.

Who knows? By the time you’ve built one of these clocks for yourself, and the hand-made Iron Throne phone charger stand to go with it, maybe ol’ George will have slipped out a new book. But don’t count on it.

If we’ve learned anything over the years, it’s that hackers like weird clocks, and they love packing as many multicolored LEDs into a device as is humanly possible. Combine both of those concepts into one project, and you’ve got a perfect storm. So as far as unnecessarily complex timepieces go, we’d say the “Crazy Clock 4” built by [Fearless Night] ranks up there among the all-time greats.

This Arduino Pro Mini powered clock syncs the current time via GPS, with a temperature compensated DS3231 RTC to keep it on the straight and narrow between satellite downlinks. Once the clock has the correct time, how do you read it? Well, at the top you’ve got a basic numerical readout for the normies, and next to that there’s a circular LED display that looks like it could double as a sci-fi movie prop. On the lower level there’s a binary clock for the real show-offs, and as if that wasn’t enough, there’s even dual color-coded analog meters to show the hours and minutes.

[Fearless Night] has provided everything you need to follow along at home, from the Arduino source code to the 3D models of the case and Gerber files for the custom PCB. Personally we think just the top half of the clock would be more than sufficient for our timekeeping needs. If nothing else it should help save some energy, as the clock currently pulls an incredible 20 watts with all those LEDs firing off.

Should you decide to take a walk down memory lane and check out some of the other interesting LED clocks we’ve featured in the past, you’d be busy for quite awhile. But for our money, it’s still hard to beat the impossibly obtuse single-LED clock.

Time is probably our most important social construct. Our perception of passing time changes with everything we do, and when it comes down to it, time is all we really have. You can choose to use it wisely, or sit back and watch it go by. If you want to do both, build a clock like this one, and spectate in sleek, sophisticated style.

[ChristineNZ]’s mid-century-meets-steampunk clock uses eight ILC1-1/8Ls, which are quite possibly the largest VFD tubes ever produced (and still available as new-old stock). In addition to the time, it displays the date, relative humidity, and temperature in both Celsius and Fahrenheit. A delightful chime sounds every fifteen minutes to remind you that time’s a-wastin’.

The seconds slip by in HH/MM/SS format, each division separated by a tube dedicated to dancing the time away. The mesmerizing display is driven by an Arduino Mega and a MAX6921 VFD driver, and built into a mahogany frame. There isn’t a single PCB in sight except for the Mega — all the VFDs are mounted on wood and everything is wired point-to-point. Sweep past the break to see the progressive slideshow build video that ends with a demo of all the functions.

Those glowing blue-green displays aren’t limited to clocking time. They can replace LCDs, or be scrolling marquees.

In this tutorial we look at how to use the neat LED Real Time Clock Temperature Sensor Shield for Arduino from PMD Way. That’s a bit of a mouthful, however the shield does offer the following:

  • four digit, seven-segment LED display
  • DS1307 real-time clock IC
  • three buttons
  • four LEDs
  • a active buzzer
  • a light-dependent resistor (LDR)
  • and a thermistor for measuring ambient temperature

led-real-time-clock-temperature-sensor-shield-arduino-pmdway-1

The shield also arrives fully-assembled , so you can just plug it into your Arduino Uno or compatible board. Neat, beginners will love that. So let’s get started, by showing how each function can be used – then some example projects. In no particular order…

The buzzer

A high-pitched active buzzer is connected to digital pin D6 – which can be turned on and off with a simple digitalWrite() function. So let’s do that now, for example:

void setup() {
  // buzzer on digital pin 6
  pinMode(6, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(6, HIGH);   // turn the buzzer on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(6, LOW);    // turn the buzzer off by making the voltage LOW
  delay(1000);                       // wait for a second
}

If there is a white sticker over your buzzer, remove it before uploading the sketch. Now for a quick video demonstration. Turn down your volume before playback.

The LEDs

Our shield has four LEDs, as shown below:

led-real-time-clock-temperature-sensor-shield-arduino-pmdway-LEDs

They’re labelled D1 through to D4, with D1 on the right-hand side. They are wired to digital outputs D2, D3, D4 and D5 respectively. Again, they can be used with digitalWrite() – so let’s do that now with a quick demonstration of some blinky goodness. Our sketch turns the LEDs on and off in sequential order. You can change the delay by altering the variable x:

void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(2, OUTPUT); // LED 1
  pinMode(3, OUTPUT); // LED 2
  pinMode(4, OUTPUT); // LED 3
  pinMode(5, OUTPUT); // LED 4
}

int x = 200;

void loop() {
  digitalWrite(2, HIGH);    // turn on LED1
  delay(x);
  digitalWrite(2, LOW);    // turn off LED1. Process repeats for the other three LEDs
  digitalWrite(3, HIGH);
  delay(x);
  digitalWrite(3, LOW);
  digitalWrite(4, HIGH);
  delay(x);
  digitalWrite(4, LOW);
  digitalWrite(5, HIGH);
  delay(x);
  digitalWrite(5, LOW);
}

And in action:

The Buttons

It is now time to pay attention to the three large buttons on the bottom-left of the shield. They look imposing however are just normal buttons, and from right-to-left are connected to digital pins D9, D10 and D11:

LED Real Time Clock Temperature Sensor Shield for Arduino from PMD Way

They are, however, wired without external pull-up or pull-down resistors so when initialising them in your Arduino sketch you need to activate the digital input’s internal pull-up resistor inside the microcontroller using:

pinMode(pin, INPUT_PULLUP);

Due to this, buttons are by default HIGH when not pressed. So when you press a button, they return LOW. The following sketch demonstrates the use of the buttons by lighting LEDs when pressed:

void setup() {
  // initalise digital pins for LEDs as outputs
  pinMode(2, OUTPUT); // LED 1
  pinMode(3, OUTPUT); // LED 2
  pinMode(4, OUTPUT); // LED 3

  // initalise digital pins for buttons as inputs
  // and initialise internal pullups
  pinMode(9, INPUT_PULLUP); // button K1
  pinMode(10, INPUT_PULLUP); // button K2
  pinMode(11, INPUT_PULLUP); // button K3
}

void loop()
{
  if (digitalRead(9) == LOW)
  {
    digitalWrite(2, HIGH);
    delay(10);
    digitalWrite(2, LOW);
  }

  if (digitalRead(10) == LOW)
  {
    digitalWrite(3, HIGH);
    delay(10);
    digitalWrite(3, LOW);
  }

  if (digitalRead(11) == LOW)
  {
    digitalWrite(4, HIGH);
    delay(10);
    digitalWrite(4, LOW);
  }
}

You can see these in action via the following video:

The Numerical LED Display

Our shield has a nice red four-digit, seven-segment LED clock display. We call it a clock display as there are colon LEDs between the second and third digit, just as a digital clock would usually have:

LED Real Time Clock Temperature Sensor Shield for Arduino from PMD Way with free delivery worldwide

The display is controlled by a special IC, the Titan Micro TM1636:

TM1636 Numerical LED Display Driver IC from PMD Way with free delivery worldwide

The TM1636 itself is an interesting part, so we’ll explain that in a separate tutorial in the near future. For now, back to the shield.

To control the LED display we need to install an Arduino library. In fact the shield needs four, so you can install them all at once now. Download the .zip file from here. Then expand that into your local download directory – it contains four library folders. You can then install them one at a time using the Arduino IDE’s Sketch > Include library > Add .zip library… command:

LED Real Time Clock Temperature Sensor Shield for Arduino from PMD Way with free delivery worldwide

The supplied library offers five functions used to control the display.

.num(x);

…this displays a positive integer (whole number) between 0 and 9999.

.display(p,d);

… this shows a digit d in location p (locations from left to right are 3, 2, 1, 0)

.time(h,m)

… this is used to display time data (hours, minutes) easily. h is hours, m is minutes

.pointOn();
.pointOff();

… these turn the colon on … and off. And finally:

.clear();

… which clears the display to all off. At the start of the sketch, we need to use the library and initiate the instance of the display by inserting the following lines:

#include <TTSDisplay.h>
TTSDisplay rtcshield;

Don’t panic – the following sketch demonstrates the five functions described above:

#include <TTSDisplay.h>
TTSDisplay rtcshield;

int a = 0;
int b = 0;

void setup() {}

void loop()
{
  // display some numbers
  for (a = 4921; a < 5101; a++)
  {
    rtcshield.num(a);
    delay(10);
  }

  // clear display
  rtcshield.clear();

  // display individual digits
  for (a = 3; a >= 0; --a)
  {
    rtcshield.display(a, a);
    delay(1000);
    rtcshield.clear();
  }
  for (a = 3; a >= 0; --a)
  {
    rtcshield.display(a, a);
    delay(1000);
    rtcshield.clear();
  }

  // turn the colon and off
  for (a = 0; a < 5; a++)
  {
    rtcshield.pointOn();
    delay(500);
    rtcshield.pointOff();
    delay(500);
  }

  // demo the time display function
  rtcshield.pointOn();
  rtcshield.time(11, 57);
  delay(1000);
  rtcshield.time(11, 58);
  delay(1000);
  rtcshield.time(11, 59);
  delay(1000);
  rtcshield.time(12, 00);
  delay(1000);
}

And you can see it in action through the video below:

The LDR (Light Dependent Resistor)

LDRs are useful for giving basic light level measurements, and our shield has one connected to analog input pin A1. It’s the two-legged item with the squiggle on top as shown below:

led-real-time-clock-temperature-sensor-shield-arduino-pmdway-LDR

The resistance of LDRs change with light levels – the greater the light, the less the resistance. Thus by measuring the voltage of a current through the LDR with an analog input pin – you can get a numerical value proportional to the ambient light level. And that’s just what the following sketch does:

#include <TTSDisplay.h>
TTSDisplay rtcshield;

int a = 0;

void setup() {}
void loop()
{
  // read value of analog input
  a = analogRead(A1);
  // show value on display
  rtcshield.num(a);
  delay(100);
}

The Thermistor

A thermistor is a resistor whose resistance is relative to the ambient temperature. As the temperature increases, their resistance decreases. It’s the black part to the left of the LDR in the image below:

led-real-time-clock-temperature-sensor-shield-arduino-pmdway-LDR

We can use this relationship between temperature and resistance to determine the ambient temperature. To keep things simple we won’t go into the theory – instead, just show you how to get a reading.

The thermistor circuit on our shield has the output connected to analog input zero, and we can use the library installed earlier to take care of the mathematics. Which just leaves us with the functions.

At the start of the sketch, we need to use the library and initiate the instance of the thermistor by inserting the following lines:

#include <TTSTemp.h>
TTSTemp temp;

… then use the following which returns a positive integer containing the temperature (so no freezing cold environments):

.get();

For our example, we’ll get the temperature and show it on the numerical display:

#include <TTSDisplay.h>
#include <TTSTemp.h>

TTSTemp temp;
TTSDisplay rtcshield;

int a = 0;

void setup() {}

void loop() {

  a = temp.get();
  rtcshield.num(a);
  delay(500);
}

And our thermometer in action. No video this time… a nice 24 degrees C in the office:

led-real-time-clock-temperature-sensor-shield-arduino-pmdway-thermometer

The Real-Time Clock 

Our shield is fitted with a DS1307 real-time clock IC circuit and backup battery holder. If you insert a CR1220 battery, the RTC will remember the settings even if you remove the shield from the Arduino or if there’s a power blackout, board reset etc:

LED Real Time Clock Temperature Sensor Shield for Arduino from PMD Way with free delivery worldwide

The DS1307 is incredibly popular and used in many projects and found on many inexpensive breakout boards. We have a separate tutorial on how to use the DS1307, so instead of repeating ourselves – please visit our specific DS1307 Arduino tutorial, then return when finished.

Where to from here? 

We can image there are many practical uses for this shield, which will not only improve your Arduino coding skills but also have some useful applications. An example is given below, that you can use for learning or fun.

Temperature Alarm

This projects turns the shield into a temperature monitor – you can select a lower and upper temperature, and if the temperature goes outside that range the buzzer can sound until you press it.

Here’s the sketch:

#include <TTSDisplay.h>
#include <TTSTemp.h>

TTSTemp temp;
TTSDisplay rtcshield;

boolean alarmOnOff = false;
int highTemp = 40;
int lowTemp = 10;
int currentTemp;

void LEDsoff()
{
  // function to turn all alarm high/low LEDs off
  digitalWrite(2, LOW);
  digitalWrite(4, LOW);
}

void setup() {
  // initalise digital pins for LEDs and buzzer as outputs
  pinMode(2, OUTPUT); // LED 1
  pinMode(3, OUTPUT); // LED 2
  pinMode(4, OUTPUT); // LED 3
  pinMode(5, OUTPUT); // LED 4
  pinMode(6, OUTPUT); // buzzer

  // initalise digital pins for buttons as inputs
  // and initialise internal pullups
  pinMode(9, INPUT_PULLUP); // button K1
  pinMode(10, INPUT_PULLUP); // button K2
  pinMode(11, INPUT_PULLUP); // button K3
}

void loop()
{
  // get current temperature
  currentTemp = temp.get();

  // if current temperature is within set limts
  // show temperature on display

  if (currentTemp >= lowTemp || currentTemp <= highTemp)
    // if ambient temperature is less than high boundary
    // OR if ambient temperature is grater than low boundary
    // all is well
  {
    LEDsoff(); // turn off LEDs
    rtcshield.num(currentTemp);
  }

  // if current temperature is above set high bounday, show red LED and
  // show temperature on display
  // turn on buzzer if alarm is set to on (button K3)

  if (currentTemp > highTemp)
  {
    LEDsoff(); // turn off LEDs
    digitalWrite(4, HIGH); // turn on red LED
    rtcshield.num(currentTemp);
    if (alarmOnOff == true) {
      digitalWrite(6, HIGH); // buzzer on }
    }
  }

  // if current temperature is below set lower boundary, show blue LED and
  // show temperature on display
  // turn on buzzer if alarm is set to on (button K3)

  if (currentTemp < lowTemp)
  {
    LEDsoff(); // turn off LEDs
    digitalWrite(2, HIGH); // turn on blue LED
    rtcshield.num(currentTemp);
    if (alarmOnOff == true)
    {
      digitalWrite(6, HIGH); // buzzer on }
    }
  }
  // --------turn alarm on or off-----------------------------------------------------
  if (digitalRead(11) == LOW) // turn alarm on or off
  {
    alarmOnOff = !alarmOnOff;
    if (alarmOnOff == 0) {
      digitalWrite(6, LOW); // turn off buzzer
      digitalWrite(5, LOW); // turn off alarm on LED
    }
    // if alarm is set to on, turn LED on to indicate this
    if (alarmOnOff == 1)
    {
      digitalWrite(5, HIGH);
    }
    delay(300); // software debounce
  }
  // --------set low temperature------------------------------------------------------
  if (digitalRead(10) == LOW) // set low temperature. If temp falls below this value, activate alarm
  {
    // clear display and turn on blue LED to indicate user is setting lower boundary
    rtcshield.clear();
    digitalWrite(2, HIGH); // turn on blue LED
    rtcshield.num(lowTemp);

    // user can press buttons K2 and K1 to decrease/increase lower boundary.
    // once user presses button K3, lower boundary is locked in and unit goes
    // back to normal state

    while (digitalRead(11) != LOW)
      // repeat the following code until the user presses button K3
    {
      if (digitalRead(10) == LOW) // if button K2 pressed
      {
        --lowTemp; // subtract one from lower boundary
        // display new value. If this falls below zero, won't display. You can add checks for this yourself :)
        rtcshield.num(lowTemp);
      }
      if (digitalRead(9) == LOW) // if button K3 pressed
      {
        lowTemp++; // add one to lower boundary
        // display new value. If this exceeds 9999, won't display. You can add checks for this yourself :)
        rtcshield.num(lowTemp);
      }
      delay(300); // for switch debounce
    }
    digitalWrite(2, LOW); // turn off blue LED
  }
  // --------set high temperature-----------------------------------------------------
  if (digitalRead(9) == LOW) // set high temperature. If temp exceeds this value, activate alarm
  {

    // clear display and turn on red LED to indicate user is setting lower boundary
    rtcshield.clear();
    digitalWrite(4, HIGH); // turn on red LED
    rtcshield.num(highTemp);

    // user can press buttons K2 and K1 to decrease/increase upper boundary.
    // once user presses button K3, upper boundary is locked in and unit goes
    // back to normal state

    while (digitalRead(11) != LOW)
      // repeat the following code until the user presses button K3
    {
      if (digitalRead(10) == LOW) // if button K2 pressed
      {
        --highTemp; // subtract one from upper boundary
        // display new value. If this falls below zero, won't display. You can add checks for this yourself :)
        rtcshield.num(highTemp);
      }
      if (digitalRead(9) == LOW) // if button K3 pressed
      {
        highTemp++; // add one to upper boundary
        // display new value. If this exceeds 9999, won't display. You can add checks for this yourself :)
        rtcshield.num(highTemp);
      }
      delay(300); // for switch debounce
    }
    digitalWrite(4, LOW); // turn off red LED
  }
}

Operating instructions:

  • To set lower temperature, – press button K2. Blue LED turns on. Use buttons K2 and K1 to select temperature, then press K3 to lock it in. Blue LED turns off.
  • To set upper temperature – press button K1. Red LED turns on. Use buttons K2 and K1 to select temperature, then press K3 to lock it in. Red LED turns off.
  • If temperature drops below lower or exceeds upper temperature, the blue or red LED will come on.
  • You can have the buzzer sound when the alarm activates – to do this, press K3. When the buzzer mode is on, LED D4 will be on. You can turn buzzer off after it activates by pressing K3.
  • Display will show ambient temperature during normal operation.

You can see this in action via the video below:

Conclusion

This is a fun and useful shield – especially for beginners. It offers a lot of fun and options without any difficult coding or soldering – it’s easy to find success with the shield and increase your motivation to learn more and make more.

You can be serious with a clock, or annoy people with the buzzer. And at the time of writing you can have one for US$14.95, delivered. So go forth and create something.

A little research has shown that this shield was based from a product by Seeed, who discontinued it from sale. I’d like to thank them for the library.

This post brought to you by pmdway.com – everything for makers and electronics enthusiasts, with free delivery worldwide.

To keep up to date with new posts at tronixstuff.com, please subscribe to the mailing list in the box on the right, or follow us on twitter @tronixstuff.

With many LED projects—like clocks—you’ll want to use a diffuser to keep light somewhat even over a wide area. Diffusers, as their name implies, diffuse light, but what if one was to instead use it as the light source itself?

This clever timepiece from Zaphunk does just that, employing an array of UV LEDs to illuminate a photochromic face. In the case of the glowing screen, the material first shines in response to the lit LEDs, then stays ‘on’ after they turn off, showing four numbers and a colon. When the photochromic cover is in use, the filament instead changes color based on the LEDs. 

The clock is implemented with an Arduino Nano, an RTC module, and a heavily modified 8-digit 7-segment display, and triggered via the press of a button on top.

This clock uses a custom built 4-digit 7-segment display made from UV LEDs. In front of the display a screen is placed that consists either of phosphorescent (“glow-in-the-dark”) or photochromic material. A push button on the top lights up the UV display which then illuminates the screen for a few seconds so that it starts glowing or changes color which then slowly fades away.

In the past, you might very well have started programming in Basic. It wasn’t very powerful language and it was difficult to build big projects with, but it was simple to learn, easy to use, and the interpreter made it easy to try things out without a big investment of time. Today you are more likely to get started using something like an Arduino, but it is easy to miss the accessible language and immediate feedback when you are doing simple projects. Annex WiFi RDS (Rapid Development Suite) is a scripting language for the ESP8266 that isn’t quite Basic, but it shares a lot of the same attributes. One example project from [cicciocb] is a scrolling dot matrix LED clock.

The code is really simple:

' Simple program using Annex and a MAX7219 dot matrix module
' by cicciocb 2019
'Set 4 8x8 displays with GPIO15 as CS pin
MAXSCROLL.SETUP 4, 15
INTENSITY = 5
'Set the first message with Annex
MAXSCROLL.PRINT "Annex"
MAXSCROLL.SHOW 31, INTENSITY
PAUSE 1000
'Set the refresh rate of the display (50 msec) - lower values -> scroll faster
TIMER0 50, SCROLLME
WAIT

SCROLLME:
'Scroll the display with the intensity defined before
MAXSCROLL.SCROLL INTENSITY 
' Set the text with the Date and Time
MAXSCROLL.TEXT DATE$ + " " + TIME$
RETURN

Of course, one reason it is simple is that Annex has a built-in set up for the LED drivers (MAXSCROLL). It also integrates with a remote web browser very easily, so you can embed HTML output in your projects.

If you look at the project’s main page, there is support for a lot of things including devices such as Neopixels, servos, LCDs, and temperature sensors. There’s also support for a lot of protocols and algorithms ranging from MQTT to PID controllers.

If you really miss Basic, you can use it on the web. Not to mention, that QuickBasic is still floating around.

We have had no shortage of clock projects over the years, and this one is entertaining because it spells the time out using Tetris-style blocks. The project looks good and is adaptable to different displays. The code is on GitHub and it relies on a Tetris library that has been updated to handle different displays and even ASCII text.

[Brian] wanted to use an ESP8266 development board for the clock, but the library has a bug that prevents it from working, so he used an ESP32 board instead. The board, a TinyPICO, has a breakout board that works well with the display.

There are also some 3D printed widgets for legs. If we’re honest, we’d say the project looks cool but the technology isn’t revolutionary. What we did find interesting though is that this is a good example of how open source builds on itself.

Of course, the library does a lot of the work, but according to [Brian] the it has several authors. [Tobias Bloom] started the code, and others have changed the library to draw ASCII characters and to support any display that uses the AdaFruit GFX-style library.

So while the code is simple, the result is impressive and is a result of [Brian] leveraging a lot of code from others — a great example of Open Source in action.

We looked at Brian’s use of this library for a YouTube subscription counter, but a clock has more universal appeal, we think — not everyone has a lot of YouTube subscribers. If you don’t have a life, you might try to recreate Tetris using the game of life.

Sometimes you have an idea, and despite it not being the “right” time of year you put a creepy skull whose eyes tell the time and whose jaw clacks on the hour into a nice wooden box for your wife as a Christmas present. At least, if you’re reddit user [flyingalbatross1], you do!

The eyes are rotated using 360 degree servos, which makes rotating the eyes based on the time pretty easy. The servos are connected to rods that are epoxied to the spheres used as eyes. Some water slide iris decals are put on the eyes offset from center in order to point in the direction of the minutes/hours. An arduino with a real time clock module keeps track of the time and powers the servos.

Check out the video after the break:

The jaw opens and closes on the hours – springs are screwed to the inside of the jaw to the outside of the skull behind the bones that surround the eyes; they’re hidden when the skull is in its box. A third servo is used as a winch to pull the jaw open from the inside of the bottom of the chin. When it releases, the springs close the mouth and the clack of the teeth replaces an hourly chime.

A bit late (or early) for Halloween, but it’s a really fun project. [Flyingalbatross1] has made the arduino code available, as well as showing plenty of images of how the parts are put together. Take a look at this this atomic clock-in-a-skull, or you make your own talking skull for Halloween!

via Reddit

We’re certainly no strangers to unique timepieces around these parts. For whatever reason, hackers are obsessed with finding new and interesting ways of displaying the time. Not that we’re complaining, of course. We’re just as excited to see the things as they are to build them. With the assumption that you’re just as enamored with these oddball chronometers as we are, we present to you this fantastic digital tachometer clock created by [mrbigbusiness].

The multi-function digital gauge itself is an aftermarket unit which [mrbigbusiness] says you can get online for as little as $20 from some sites. All he needed to do was figure out how to get his Arduino to talk to it, and come up with some interesting way to hold it at an appropriate viewing angle. The mass of wires coming out of the back of the gauge might look intimidating, but thanks to his well documented code it shouldn’t be too hard to follow in his footsteps if you were so inclined.

Hours are represented by the analog portion of the gauge, and the minutes shown digitally were the speed would normally be displayed. This allows for a very cool blending of the classic look of an analog clock with the accuracy of digital. He’s even got it set up so the fuel indicator will fill up as the current minute progresses. The code also explains how to use things like the gear and high beam indicators, so there’s a lot of room for customization and interesting data visualizations. For instance, it would be easy to scrap the whole clock idea and use this gauge as a system monitor with some modifications to the code [mrbigbusiness] has provided.

The gauge is mounted to a small project box with some 3D printed brackets and bits of metal rod, complete with a small section of flexible loom to cover up all the wires. Overall it looks very slick and futuristic without abandoning its obvious automotive roots. Inside the base [mrbigbusiness] has an Arduino Nano, a DS1307 RTC connected via I2C, a voltage regulator, and a push button to set the time. It’s a perfectly reasonable layout, though we wonder if it couldn’t be simplified by using an ESP8266 and pulling the time down with NTP.

We’ve seen gauges turned into a timepiece before, but we have to admit that this is probably the most practical realization we’ve seen of the idea yet. Of course if you want to outfit the garage with something a bit more authentic, you can always repurpose a Porsche brake rotor.

With the June solstice right around the corner, it’s a perfect time to witness first hand the effects of Earth’s axial tilt on the day’s length above and beyond 60 degrees latitude. But if you can’t make it there, or otherwise prefer a more regular, less deprived sleep pattern, you can always resort to simulations to demonstrate the phenomenon. [SimonRob] for example built a clock with a real time rotating model of Earth to visualize its exposure to the sun over the year.

The daily rotating cycle, as well as Earth’s rotation within one year, are simulated with a hand painted plastic ball attached to a rotating axis and mounted on a rotating plate. The hand painting was done with a neat trick; placing printed slivers of an atlas inside the transparent orb to serve as guides. Movement for both axes are driven by a pair of stepper motors and a ring of LEDs in the same diameter as the Earth model is used to represent the Sun. You can of course wait a whole year to observe it all in real time, or then make use of a set of buttons that lets you fast forward and reverse time.

Earth’s rotation, and especially countering it, is a regular concept in astrophotography, so it’s a nice change of perspective to use it to look onto Earth itself from the outside. And who knows, if [SimonRob] ever feels like extending his clock with an aurora borealis simulation, he might find inspiration in this northern lights tracking light show.

This is a spectacular showpiece and a great project you can do with common tools already in your workshop. Once you’ve mastered earth, put on your machinists hat and give the solar system a try.



  • Newsletter

    Sign up for the PlanetArduino Newsletter, which delivers the most popular articles via e-mail to your inbox every week. Just fill in the information below and submit.

  • Like Us on Facebook