I connected 2 74HC595 shift register ICs together in a daisy chain and encountered a very annoying effect. I searched the internet quite long for the solution and there is no mention of it anywhere.
The setup
2 x 74HC595 daisy chained
16 x LED with resistor
1 x Arduino UNO
Scenario #1
I turn on the LEDs one by one from 0 to 15. --- > It works perfectly.
I turn off the LEDs one by one from 0 to 15. --- > When i turn off the number 0 it also turns off the number 8. When i turn off the number 1 it turns the number 8 back on. The rest of the sequence is fine.
Scenario #2
I turn off all the LEDs and turn on number [ i+8 ]. After that i blink number [ i ]. --- > It works perfectly.
I turn on all the LEDs and start blinking the number [ i ] . --- > Number [ i+8 ] also blinks.
I tested it with several codes found on the internet and shows the same effect every time.
I tested it with the ShiftOut tutorial.
I tested it with advanced shiftout without the 8 bit restriction problem.
I tested it with delay and without delay functions.
All the same problem.