I have a MCP23009 IC that I want to use as out put. So far so good, I used it once before as input and the ..17 as output, but... I get a strange result. The LEDs will blink, but only if I connect them anode/plus to the V+ and cathode/minus to the mcp pin This is the source: #include <Wire.h> #in…

MCP2300x behaviour

macegr April 27, 2012, 7:57am 2

The MCP23009 outputs are open-drain.

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