Flexball Is a Flexible PCB Ball with 100 LEDs and WiFi

Electrical engineer 'moekoe' originally had planned to design a ball that could display text messages on a round LED matrix, but the distances between the arms prevented that from happening. Still, the Flexball is no less impressive with its flexible nine RGB arms. As with any flexible circuit board, some rules need to be followed, or rather a list of don'ts when building a project, including not using traces with corners or edges, as they tend to crack when bent. The same goes for GND planes, which tend to break when flexed.

Flexball offers a simple design and is outfitted with 100 WS2812 2020 addressable RGB LEDs, which are driven by an ESP8285-01F, the smallest module in Espressif's arsenal. It also packs an ADXL345 accelerometer, but it's unclear why he included the sensor. That said, moekoe positioned every component on the ball by hand and soldered them all using his makeshift hot plate (a clothes iron) and a reflow gun. However, he had to keep temperatures low in order not to damage the PCB.

As seen in the video below, moekoe had to painstakingly resolder some of the LED connections by hand that was not cemented during the reflow process, but never the less, the end result looks impressive. The code he used is based on the FastLED library, which can drive most addressable LEDs, including APA102, SK9822, and WS2812.

Moekoe has uploaded a detailed walkthrough of his Flexball on his Instructables page for anyone who would like to recreate his project.