I'm testing/debugging a sketch that uses the 74HC595 shift register on an Arduino-Compatible Teensy3.2 (3.3V).
I want to connect the 8 outputs of the Shift Register back to 8 input pins on the board.
Would I need resistors between the output of the Shift Register and the Arduino input? How to know the current flowing from the SR output?
I did have a look at the datasheet but that just confused me more: https://www.taydaelectronics.com/datasheets/A-251.pdf