Good clocks are generally those that keep time well. But we think the mark of a great clock is one that can lure the observer into watching time pass. It doesn’t really matter how technical a timepiece is — watching sand shimmy through an hourglass has its merits, too. But just when we were sure that there was nothing new to be done in the realm of 7-segment clocks, [thediylife] said ‘hold my beer’ and produced this beauty.
A total of 28 servos are used to independently control four displays’ worth of 3D-printed segments. The servos pivot each segment back and forth 90° between two points: upward and flat-faced to display the time when called upon, and then down on its side to rest while its not needed.
Circuit-wise, the clock’s not all that complicated, though it certainly looks like a time-consuming build. The servos are controlled by an Arduino through a pair of 16-channel servo drivers, divided up by HH and MM segments. The Arduino fetches the time from a DS1302 RTC module and splits the result up into four-digit time. Code-wise, each digit gets its own array, which stores the active and inactive positions for each servo. Demo and full explanation of the build and code are waiting after the break.
When it comes to 7-segment displays, we say the more the merrier. Here’s a clock that uses pretty much all of them.
I’d really like to see someone make a completely mechanical 7 segment clock
that would be cool. So it could start with some synchronous motor and then a bunch of these
https://www.fabbaloo.com/blog/2019/11/18/design-of-the-week-7-segment-controller connected with proper gearing ratios.
Nice clock, but what I really want to know is, what is that nice collapsible work table that appears at 3:11?
Looks like the KETER folding work table
This is just a flip segment display powered by servos instead of electromagnets. You could also use small dc motors and just stall them for a fraction of a second to make sure the segment is fully flipped, or even steppers and just keep track of the steps. It is a nice build but it is far from a new tech.
I am going to steal that idea – I have a big bag of phone vibrating motors from a Bristle bot thing.
I made a similar servo driven seven-segment display years ago but with just an Arduino clone and NO motor drivers. See if you could guess how I did it.
http://g33k.blogspot.com/2013/12/servo-driven-7-segment-display.html
I made a large 7 segment display sign for a local charity with no motors or computers of any kind. A person rotates pieces of PVC pipe that are black on one side and day glow pink on the other to activate the segments. It took the people who saw it a while to figure out that it was not an electirc sign. It works perfectly for what it was intended for. No power, no wires, big digits, you can see it in bright light and you can see it in dim light. Oh, and it was really inexpensive to build. This works great for anything where the numbers do not change very often. I could see building one for kids sporting events.
I like it, but I am missing a mechanism for blinking the seconds, also would make a nice background sound
A really good writeup.
Nice visual effect spoils the working servo noise. Why there is no quiet servos on the market…?