Winners Announced: Code Challenge #1

It’s been a week since we launched our quick Code Challenge #1, which it’s time to announce a winner! It was tricky. While the volume of entries wasn’t high, there’s no questioning the quality of our winning entries.

But first, let’s check a few different approaches to the challenge we supplied.

My turn first!

As I set the rules for this challenge, I thought it was only fair that I take the challenge on firs.

(* And no, I can’t award the prize to myself… well, I’m pretty sure I can’t… right?!? ).

I played around with both CSS and SVG solution – two of my stronger suits – and decided to not use any scripting. As there’s no true random function available in either CSS or SVG, the was always to make regular animation loops appear more random than they actually are. Here’s my solution.

See the Pen Pure CSS ‘organic-looking’ EKG Animation by Alex (@alexmwalker) on CodePen.

Feel free to pick through the code, but the main points of interest are:

  • The EKG line animation only uses one external SVG and two separate animation loops.
  • One CSS animation (travel) loops the green gradient from left to right. An overlaying mask shapes the EKG line.
  • I created 6 unique ‘EKG heartbeats’ on the SVG graphic and set them up as sprite keyframes. I’m switching these keyframes to make them look randomized (I’ve added tiny numbers at the bottom to make the keyframe switching more obvious).
  • The second animation treats each ‘heartbeat’ as a sprite and switches to a new one on each pass – but this is timed to only take place in the dark section of the loop when it can’t be seen.
  • Of course, as each ‘heartbeat unit’ uses exactly the same CSS animation, we would normally expect them all to show the same keyframes. The trick to make them all appear different is to offset their starting times using animation-delays. And if we use negative delays (e.g. animation-delay: -9s) we can jump immediately to any mid-point in an animation loop. That’s a really useful performance trick.
  • All animation is controlled by a single Sass variable at the top of the CSS window - $animation-time: 5s;. Changing that number will alter the big readout number and the EKG speed.
  • It’s built for Chome and not widely tested but should work anywhere.

Third Prize: PaulOB

We’ve been very lucky to have Paul as a longtime contributor, mentor and advisor to SitePoint users for well over a decade (possibly approaching two?). In this case, he sacrificed precious holiday time on the sun to produce a tasty SVG solution.

See the Pen Machine that goes Ping! by Paul O’Brien (@paulobrien) on CodePen.

Paul said:

It’s just an SVG for the graph and an animated linear gradient to provide the motion effect. If I had time I would draw it properly and make it responsive and not just repeat the same svg each time to make it look a little bit random.

Must get back to the swimming pool now :slight_smile:

Paul, we salute you, sir!

(Also, we’ll work out which SitePoint t-shirt, can holder or assorted shwag we can send you.)

Equal First prize: nickwatton

While there weren’t a huge quantity of entries for this first code challenge, there was certainly no lack of quality with the top two entries. In fact, we thought the best 2 entries were so worthy of reward that we decided to award them both $200 Amazon Gift Card prizes.

Nickwatton’s entry was exactly the kind of thing I had in mind.

See the Pen Machine that goes Ping! by Nick Watton (@2Mogs) on CodePen.

As Nick explains, his solution:

Uses particle systems, because I like them :smiley: Also, you can get a very cheap trail effect with canvas by filling the drawing context with a nearly transparent black, which makes the fading trail for my ‘ping’ line.

RAF keeps the whole animation running smoothly, with the heartbeat animations controlled with a recursive setTimeout(). I am using the setTimeout() to drive effects that are not per-frame, and it also means I can fire this at slightly random intervals, for an organic feel.
The heartBeat() method controls and lightly randomizes the pulse rate, seen in the heart and pulse line.

Nick’s JS and Canvas approach offers flexibility that is hard to match with other approaches. I can’t imagine how you could begin to mimic those particle effects with an SVG based method.

It’s also relatively easy to slightly randomize the speed of the animation. This is tough to fake without JS but really sells the plausibility of this animation.

Equal First prize: davidomarfch

David submitted his entry just before the cut-off time – and we’re so glad he made it. I have to admit this one had me grinning from ear to ear.

See the Pen Machine that goes Ping! by David Omar Flores Chávez (@davidomarf) on CodePen.

Firstly, David started out with some serious research into how a real ECG machine produces its output and built that knowledge into his animation. He’s also added ebbing and flowing blood pressure, temperature, oxygen saturation readings and even haemoglobin count. This thing feels legit.

But David also added two killer X-factor elements.

  1. Audio: The classic machine ‘boop…boop…boop…’ adds so much drama when the heart rate increases.
  2. Interactivity: Beside some automatic ‘passive randomness’, David lets the user control the heartrate via the cursor position. Move to the far left to put your patient to sleep - move to the right to give them an adrenalin jolt.

That finite control of the ECG speed makes this unit potentially genuinely useful in a movie/TV set scenario.

Like Nick’s solution, the ECG unit is written to canvas with JavaScript but David uses the P5.js library to handle the drawing and sound. I haven’t used P5 before, but with module for drawing, animation and audio, it seems like a great foundation to base a project like this on.

All up, a super impressive contribution.

Both thanks and congrats to David, Nick, and Paul. We’ll be in contact shortly.

What’s Next? Code Challenge #2: The CSS Battle

For our next challenge we’re partnering with our friends at to sponsor Battle round #4 . There are 3 cash prizes and 20 SitePoint Premium Memberships to compete for over a three week period. Details to come in the next post.


Congratulations @nickwatton and @davidomarfch! Great to have such creative talent here. smile

Congratulations, too, to @PaulOB - and kudos for dragging himself away from the pool long enough to enter. lol


Well done to Nick & David for stunning quality of their entries which are deserved winners :slight_smile:

Thanks also to Alex for the challenge and his examples which were great also.

I love to see how people approach these challenges in different ways and also inspire me to learn something new along the way :slight_smile:


Thank you to Alex for a cool challenge.
Great to see how other people work - always something to learn!!
And as pool-side Paul shows - you don’t have to spend a great deal of time - just have a go. Can’t win if you don’t enter :smile:
Well done everyone, we are all winners :star2:


Hey! Thanks for making this challenge. I had lots of fun, and learned something new.

And as Nick and Paul already said, looking at other people’s solutions makes you learn. I knew CSS could make some animations, but what I imagined wasn’t even close to animations you submitted!


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