Persistence of imaginative and prescient (PoV) is a visible phenomenon that happens because of our eyes’ (or relatively mind’s) lack of ability to maintain up with quick movement. This is the reason we see movement blur, like a digicam with the shutter left open for a very long time. It’s also why, for instance, you don’t discover your LED mild bulbs flickering, though they most likely are — you simply see fixed mild as a result of the flickering occurs quicker than you may understand. That is what makes PoV shows doable and this DIY full-color PoV show designed by lhm0 is a really versatile instance.
PoV shows like this work identical to your LED mild bulbs, simply with movement. A row of LEDs spins quick sufficient that you just solely see a stable aircraft of sunshine. By modulating the brightness and colour of the LEDs in sync with the rotation, it may possibly show photos and textual content.
This design comprises 56 RGB LEDs, which is the radial decision throughout the diameter. The polar decision is more durable to outline, as a result of it’s the results of the rotation velocity and LED refresh charge.
The beauty of lhm0’s design is that’s fairly easy from a mechanical perspective. The LEDs, microcontrollers, and many of the different elements mount onto the highest PCB that spins. The motor and energy provide mount onto the stationary backside PCB. This might usually require one thing like a slip ring to move energy from the underside to the highest, however that might create friction. As an alternative, lhm0 built-in wi-fi energy switch between the boards. That signifies that the one bodily contact the highest board makes is with the motor shaft. That motor is for a CD drive. To keep up stability and stop vibration, lhm0 fastidiously distributed the elements with screws and nuts performing as counterweights.
As a result of velocity is crucial for a PoV show like this one, lhm0 used two microcontrollers. The primary, a Raspberry Pi RP2040, is devoted to controlling the LEDs. The second, an ESP32, makes use of its built-in Wi-Fi adapter to connect with the web to tug knowledge (like time and climate). It additionally hosts an internet interface the place the person can configure settings and choose what they need to show.
That is able to displaying every kind of content material, however lhm0’s demonstrations embody easy movies, clocks, and climate forecasts.
