Introduction - If you have any usage issues, please Google them yourself
This driver applies to 51 microcontroller (5V or 3.3V), liquid crystal VCC connected to 5V or 3.3V
Modify the bias voltage can change the brightness of the 5110 dot matrix display
5110 5V when the bias voltage is changed to (0xa7,0), then 3.3V is changed to (0xc0,0)