Tutorial: Adding Digital I/O To Your Arduino

Just posted a new article, Adding Digital I/O To Your Arduino: Part 1 - The 74HC595, on Woolsey Workshop describing how to add digital outputs to your Arduino board using the 74HC595 8-bit serial-in parallel-out shift register IC.

Just posted a new article, Adding Digital I/O To Your Arduino: Part 2 - The 74HC165, on Woolsey Workshop describing how to add digital inputs to your Arduino board using the 74HC165 8-bit parallel-in serial-out shift register IC.

Just posted the final part of the three-part series, Adding Digital I/O To Your Arduino: Part 3 - The MCP23017, on Woolsey Workshop describing how to add both digital inputs and outputs using the MCP23017 16-Bit I2C I/O Expander With Serial Interface IC.

Might want to mention a decoupling capacitor is always a good thing to add in such circuits.

Thank you for your suggestion. I had thought about it and mentioned it in the first two parts, but since it was not called out specifically in the MCP23017 datasheet, I left it out. You are right though, one should always be added for thoroughness.

larryd:
Might want to mention a decoupling capacitor is always a good thing to add in such circuits.

Capacitor added. Thanks again for your suggestion.

Thanks for your contributions :slight_smile: .