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spi [2019/03/31 14:49] (current)
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 +====== SPI ======
 +
 +Watch this video [[https://​www.youtube.com/​watch?​v=AuhFr88mjt0|link]].
 +
 +The SPI port has a bunch of settings that the bus pirate can let you control. ​
 +The first one is the speed. SPI is not like I2C. It is synchronous and sends out its 
 +own clock and this is what governs the speed. SPI is full duplex meaning that reading ​
 +and writing happens at the same time over two seperate data lines.
 +
 +It is a master-slave protocal where all communication is initiated by the
 +master. Addressing is done through a dedicated slave select line to to each
 +peripheral. ​
 +
 +SPI Lines are:
 +  * MISO  - Master In Slave Out
 +  * MOSI  - Master Out Slave In
 +  * SCL   - Serial Clock Line
 +  * SS    - Slave Select Line (for every peripheral)
 +
 +A quick about SPI is that because it is a synchronous full duplex master/​slave
 +bus, data can transfer can only be initiated by the master, including when the
 +master wants the slave to talk. This is why master has to send dummy bytes of
 +data when reading bytes back from the slave.
 +
 +
  
  • spi.txt
  • Last modified: 2019/03/31 14:49
  • (external edit)