<https://www.cnx-software.com/2019/06/20/obsidian-esp32-board-raspberry-pi-form-factor/#article>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.cnx-software.com/2019/06/20/obsidian-esp32-board-raspberry-pi-form-factor/?amp=1>