https://github.com/rjbatista/tm1638-library/wiki/Reference
https://ameblo.jp/usu-kuchi/entry-12275761999.html
http://hananekolog.blogspot.com/2013/05/jy-lkm1638-arduino.html
https://electronic.hateblo.jp/entry/2019/04/16/032946
https://pocketcomputer.jimdo.com/mbed-arduino/
TM1638.pdf