2021 Jun 25, 04:27 PM
(This post was last modified: 2021 Jun 25, 06:43 PM by astrogerard.)
@Rob,
Lets do a little experiment.
In the picture from the Wiki there is a purple wire connected to pin 13 on all the hc595
Can you pull that wire from the Pi and connect this wire to GND? And test again?
Pin 13 of the HC595 is inverted OE (Output Enable). According to the datasheet, if this pin is high the output of the HC595 goes in "high impedance" mode which essentially means it is neither high or low.
I have unfortunately no spare HC595 to test so everything I suggest is based on theory.
--Gerard
Lets do a little experiment.
In the picture from the Wiki there is a purple wire connected to pin 13 on all the hc595
Can you pull that wire from the Pi and connect this wire to GND? And test again?
Pin 13 of the HC595 is inverted OE (Output Enable). According to the datasheet, if this pin is high the output of the HC595 goes in "high impedance" mode which essentially means it is neither high or low.
I have unfortunately no spare HC595 to test so everything I suggest is based on theory.
--Gerard