This is the last of the series of using the Bus Pirate and the Bus Pirate Demo Board.  This one is using the SPI EEPROMs.  The board has two of the same EEPROM (well, one is SOIC, the other is DIP, but other than that, they’re the same).

Connections

The power connections for this are the same as the connections you’d use for an I2C device – ground and power (I used 3.3V) + pull-up to Vin.

The data connections are pretty simple because the Bus Pirate is marked with MISO, MOSI, CLK, and CS (Master In Slave Out, Master Out Slave In, Clock, and Chip Select) and the demo board is marked with MISO, MOSI, SCK, and CS (there is one difference, and the process of elimination fixes that!).

Writing and Reading to the EEPROM

There are two steps to write to the EEPROM – send a write-enable command and then write to it.

[0x06] – write enable command

[0x02 0 0 1 2 3 4 5] – 0x02 is write, 0 0  is the address to write to, and 1 2 3 4 5 is the data to write

[0x03 0 0 r:5] – 0x03 is the read command, 0 0 is the address, and r:5 means read five bits.

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That’s it with the demo board!  Expect that the Bus Pirate will make more appearances on this blog, though.

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