IIC (STM32)

IIC(Inter－Integrated Circuit) Bus is a kind of bus which is made by PHILIPS company-developed Two wire serial bus

High speed IIC The bus can reach 400kbps above .

IIC Signal sequence diagram

IIC There are three types of signals in the process of data transmission , Start signal 、 End signal and answer signal .

Start signal ：

SCL  For high voltage ,SDA  Jump from high level to low level , Start sending data .
SCL = 1
SDA = 1 
SDA = 0 

End signal ：

SCL  For high voltage ,SDA  Jump from low level to high level , End data transfer .
SCL = 1
SDA = 0 
SDA = 1

Answer signal ：

 Every byte sent （8 individual bit）, One byte transmission 8 The ninth clock period after the first clock 
 The receiver must return a... After receiving the data ACK The reply signal is sent to the transmitter , So that data can be transmitted .
 The reply  “0”, Non response  “1”