Designed for China (ebay) module 4 digits x 7 segments led with 2 pcs 74HC595
This module must use multiplexing positions, not possible set static show bits all at once!
Show integer from -999 to +9999
If number > 9999 display upper ----
If number < -999 display lower ____
Optional set static show decimal point on any position
Float number must be converted to integer!
Version 1.1
Created by Lubomir Hron (Czech Republic)