Summary
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This ESP32 samples one pixel per laser pulse and converts multiple pulses into 10 billion FPS slow light motion.
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It uses a stable, repeatable laser and time-matched sampling so that successive pixels create a continuous frame-by-frame movie.
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No exotic high-speed camera required; Long-term build-up in ESP32 reconstructs ultra-slow-motion video.
People have been able to achieve some amazing things with an ESP32, but I think building one to capture a laser pulse and create a 10 billion FPS video showing the light traveling across the room takes the biscuit. While an ESP32 certainly isn’t capable of recording a video in slow motion, someone had a great idea on how to achieve a similar effect using a microcontroller.
This ESP32 project generates continuous video from multiple individual laser pulses
Now you can see with your own eyes how the light moves
in an article about ESP32 subreddituser doubleyow showed off his eye-catching new project. They used an ESP32 to track the pulse of the laser beam, then built a 10 billion FPS video that allowed them to see the pulse in slow motion. In the video above, you literally see light travel.
So how did doubleyow achieve this? Well, they didn’t connect a 10 billion FPS camera to the ESP32 and record only one pulse. This would be very demanding on the microcontroller and is not a setup you would see in someone’s garage. Instead, doubleyow set up the laser to pulse steadily and predictably. Then they let the laser pulse on its own for a while.
The ESP32 tracked the laser and recorded one pixel of each pulse at a given position at a given time. Since the speed of light did not change and the laser pulse did not change, the ESP32 slowly collected many consecutive pixels from many different laser pulses. After doing this, he combined all the images into one video.
What you see above is not the result of recording a single laser pulse, but rather the result of recording many identical laser pulses at different times and stitching them together. So it’s one continuous video of a single pulse and more like a patchwork quilt that makes up a whole. Fortunately, because the laser is coherent, if you slow down time and look at a single pulse, the result is actually what you would see.
If you’re brave enough to read all the technical stuff that goes into making this project happen, doubleyow separate Reddit post they detail how they got the ESP32 to do this in the first place.
