Persistence of imaginative and prescient (PoV) is a visible phenomenon that happens because of our eyes’ (or quite mind’s) incapacity to maintain up with quick movement. That is why we see movement blur, like a digital camera with the shutter left open for a very long time. It’s also why, for instance, you don’t discover your LED gentle bulbs flickering, although they most likely are — you simply see fixed gentle as a result of the flickering occurs quicker than you’ll be able to understand. That is what makes PoV shows attainable and this DIY full-color PoV show designed by lhm0 is a really versatile instance.
PoV shows like this work identical to your LED gentle bulbs, simply with movement. A row of LEDs spins quick sufficient that you simply solely see a stable airplane of sunshine. By modulating the brightness and shade of the LEDs in sync with the rotation, it might show photos and textual content.
This design accommodates 56 RGB LEDs, which is the radial decision throughout the diameter. The polar decision is tougher to outline, as a result of it’s the results of the rotation pace and LED refresh fee.
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 may usually require one thing like a slip ring to cross energy from the underside to the highest, however that may create friction. As a substitute, lhm0 built-in wi-fi energy switch between the boards. That implies that the one bodily contact the highest board makes is with the motor shaft. That motor is for a CD drive. To take care of stability and stop vibration, lhm0 rigorously distributed the elements with screws and nuts performing as counterweights.
As a result of pace 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 hook up with the web to tug knowledge (like time and climate). It additionally hosts an online interface the place the consumer can configure settings and choose what they need to show.
That is able to displaying every kind of content material, however lhm0’s demonstrations embrace easy movies, clocks, and climate forecasts.