Differences

This shows you the differences between two versions of the page.

@@ Line 1: / Line 1: @@
+====== 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.