10.驱动两大利器: 电路图:作用:通过电路图找到寄存器
和芯片手册
芯片手册第六章:
GPFSEL0 GPIO Function Select 0 功能选择 输出/输入 (GPIO Function Select Registers) 32位
14-12 001 = GPIO Pin4 is an outpu
GPSET1 GPIO Pin Output Set 0 输出1
0 = No effect
1 = Set GPIO pin n
GPCL R0 GPIO Pin Output Clear 0 清0
0 = No effect
1 = Clear GPIO pin n