Leds for multiple chip select active low pin state indicator

Thread Starter


Joined Jan 31, 2019
Hi everyone, first post so please excuse mistakes/errors, basically I'm building a circuit that uses 8 port expander chips which have chip select pins that are active low, I just need an indication via led as to which one is currently active, an 8 channel device would be easiest for obvious reasons, I'm using a CD74HCT154E to select desired port expander chip (INS8243)


Joined Feb 20, 2016
Just add an LED with series resistor, cathode to the CE line, anode to series resistor, other end of the resistor to the +5V.
A high intensity LED and 1K resistor should work well.