Sensor/Actuator interface with micro controller

• Sensor data has to be processed and transmitted
• Sensor connect to a microcontroller through establish interfaces

Serial interface: UART

• Asyncronous: No clock
• Simple connection
• COmmon porotocl used for full duplex serial communcation
• Send one bit at a time

Serial interface: SPI

• Synchronous
• One master and one slave
• Short distance communication (embedded system)
• Max clock rate: 12.5 MHZ

  Signals:

• Clock
• Chip select
• Master out, slave in

• Master in, slave out

• The device that gen the clock sig is master
• data trans mitted between master and slave is sych to the clock generated by the master

Serial Interace:I2C

• Syncrhonous
• Follows the clk data
• Both master and slave can send data
• There are multiple slaves, address bits define which slave to communcate to
• Read write bit: Show if the master wants to request or send data
• All the slaves will look at the address and see ifits matches it address
  • Yes: Pulls the data line to low (This data line is shared to low but only one can pull) - Master will then knows that the slave exist
    • Data is sent
    • This is followed by the ack lines that show that the data is send or recieved
• Ends when the SDA goes high after SCL

Difference between SPI and I2C

• SPI: Can keep sending data I2C: Based on data frame

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