Multiple MCP23016 Questions...
Orion
Posts: 236
I'm currently drawing up a card to hold the mcp23016 and some optos and triacs.· I have jumpers for the address lines and wish to be able to stack multiples of these cards together.· Also I want to tie the interrupt pins together and feed them into a BS2p using the polling features.
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I have·few questions
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1.· Can the interrupt pins be tied together and put on a BS I/O pin·directly?· Pull-up required? (each mcp is divided into 8 inputs 8 outputs)
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2. Address pins.· Must they be pulled low or high, or will low and not·connected (floating) work?
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3. SCL & SDA· One set of pull-up resistors (4.7k) needed per I2C buss.· Or does each device need them.· I assume just one set, right?
·
·
I have·few questions
·
1.· Can the interrupt pins be tied together and put on a BS I/O pin·directly?· Pull-up required? (each mcp is divided into 8 inputs 8 outputs)
·
2. Address pins.· Must they be pulled low or high, or will low and not·connected (floating) work?
·
3. SCL & SDA· One set of pull-up resistors (4.7k) needed per I2C buss.· Or does each device need them.· I assume just one set, right?
·
Comments
2. No, high or low -- do not let them float.
3. Just one set of pull-ups; usually on the "master" side of the circuit.
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Jon Williams
Applications Engineer, Parallax
Dallas Office