This servo-controlled Larson scanner requires no LEDs

All things considered, it’s easy to have an LED strip light up in sequence and have it bounce back and forth. It’s another thing entirely to turn a simple animation into a real Larson scanner, with smooth transitions and controlled fades. Forget about LEDs altogether and make a servo-operated Larson scanner – well, let’s call it an interesting lesson in hardware abstraction.

The Larson Scanner is named after famed television producer Glen A. Larson because he liked to incorporate it into programs such as battlestar galactica and knightis actually difficult to implement in hardware because of the trailing faded tail that appears when the guide pixels dance back and forth across the display. [Eric Gunnerson] Decided to implement this and other animation effects more easily using Fade, a custom framework for LED animation running on the ESP32.

LED animations are great, but what about the servos? Can the Fade be modified to support them?Thanks to Fade’s architecture and [Eric]Existing support for non-addressable LED functionality via PWM signal. By adding UDP connections to place multiple ESP32s under the control of a central microcontroller, it is even possible to support more than 16 PWM channels on the ESP32.

The video below shows [Eric]Servo support demonstration with an eight-channel electromechanical Larson scanner. Each “pixel” is a painted ping pong ball swinging back and forth on a hobby server, and the whole thing sounds just as bad as you’d imagine. If you squint just right, the effect looks pretty convincing, but that’s not the point.The real story here is [Eric]Thoughtful architecture makes modding easier than starting from scratch.


Source link


Your email address will not be published. Required fields are marked *