PCF8574(A) GPIO expander guide issue

Hi all,

i tried to follow this guide and did the exam shema as showed. The LED did turn on and for this part it’s ok.

but when it comes to the soft part I successed in uploading the soft to the makerbuino but failed just after : when i launch the app the led is still on whatever i do and on the makerbuino’s screen it’s always looping LED off - LED on, whatever i do (switching cable and so on).

Do someone can help me?

Sounds like the pin that reads the switch has a LOW signal all the time. Please check if you’ve turned the switch 90°, because two pins on both sides are internally connected.

Or you could use a jumper-wire to simulate a button.