For educational purposed I designed a PCB (Printed Circuit Board).
This is the third version. The first version had some bugs :-), the second some other labels.
It is used for IoT classes for programming Java (Object Oriented Programming). Because of the use of Pi4J and therefore the use of WiringPi.
Here it is in action, with a DS1820 sensor connected to the 1-Wire interface (WiringPi IO pin 07):
The design and schema of the PCB is available at easyeda.com
I ordered 100 pcs @ easyeda/JLCPCB and they were produced and delivered in 8 days in the Netherlands. Great work!
Here are some pictures of the board and usage: