I've just had my first go at getting a shift register to work with my Arduino.. it was almost flawless, but I seem to be missing my first bit.
I followed the guide here, but using only one shift register: http://arduino.cc/en/Tutorial/ShiftOut
It took a little while to figure out, but it appears as though pin Q1 on my shift register is lighting up when I send the number 2, Q2 is high for 4, Q3 = 8 etc.. when I call shiftout() with the number 1 no LEDs come on.
I checked my wiring and it seems fine.. then I double checked and it's definitely fine.
The only things I can think of are: 1. My shift register is slightly different to the one they're using.. it's a 595N, not a 595. 2. I've done something wrong in the code..
digitalWrite(latchPin, LOW); shiftOut(dataPin, clockPin, MSBFIRST, 1); digitalWrite(latchPin, HIGH);
Does anyone have any tips on debugging this issue?