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====MCP23017 I2C Address ====
====MCP23017 I2C Address ====
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This is where the I2C Address in defined. That is the specific I2C bus address that the MCP23017 will pay attention to, and until it is established that you are communicating with this, there is little point in attempting anything else. It proves that the MCP23017 and the Raspberry Pi are communicating correctly over the I2C bus.
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This can be checked by using a command line tool on the raspberry Pi which communicates with the I2C bus.
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i2cdetect -y 1
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====MCP23017 INT-A Pin ====
====MCP23017 INT-A Pin ====
====MCP23017 INT-B Pin ====
====MCP23017 INT-B Pin ====