Recent posts to MCP23017: inputs OK, but outputs won’t switch (CODESYS on Raspberry Pi)https://forge.codesys.com/forge/talk/Runtime/thread/72918e9b39/2025-09-17T10:12:34.147000ZRecent posts to MCP23017: inputs OK, but outputs won’t switch (CODESYS on Raspberry Pi)MCP23017: inputs OK, but outputs won’t switch (CODESYS on Raspberry Pi)2025-09-17T10:12:34.147000Z2025-09-17T10:12:34.147000Zastutoskihttps://forge.codesys.com/u/astutoski/https://forge.codesys.com43c048a6b5af8a022af438294c2612f9083f8d47<div class="markdown_content"><p>Hi everyone,<br/>
I’ve connected and configured an MCP23017 over I²C on a Raspberry Pi using the available CODESYS/RPi library. Input reading works fine (I can reliably read a digital input). However, I can’t get any output pin to change state.</p>
<p>Example: when I try to drive PB0, the watch shows MCP23017.Out_B.0 = TRUE (1), but there is no actual output on the pin (no voltage change).</p>
<p>Anyone solved this</p></div>