基本
http://n.sfs.tw/content/index/11016
直角等
https://mbotandstem.blogspot.com/2017/04/mbot-line-follow-car.html
兩組光感器
https://sites.google.com/a/qtm.ks.edu.tw/qtm052-org/3-ban-ji-jing-ying-yu-fu-dao/mbot/mbot-bi-zhang-xun-ji3
https://bbs.elecfans.com/jishu_535381_1_1.html