Addressable WS2812B RGB LEDs are used for the headlights. A controller is built into each of these LEDs, which makes it possible to define the colour and brightness of each LED individually. The data is transferred to the first LED via a bus line connected to a pin from the micro:bit. This bus line is then continued from the first LED to the second LED, from the second LED to the third LED and so on. The data is then transferred from LED to LED via this bus line. In other words, the LEDs form a kind of light chain, where each light can be controlled separately.
In the case of the Joy-Car, this LED chain has been solved in a way, that 2 WS2812B LEDs are mounted on one headlight module. These two LEDs are already connected to the bus line on the circuit board. The connection pins of the board have a „Din“ (data in) and a „Dout“ (data out) pin. These pins are used to connect the boards together. To keep the wiring clear, the LED boards are not directly connected to the bus line. The bus line is led back to the mainboard of the Joy-Car and is routed from the „Dout“ pin to the „Din“ pin of the following LED module.
ATTENTION! If a LED module is not connected, the modules further back in the chain no longer work, because the data connection is interrupted.