I have now successfully learned how to control a single 8 bit shift register 74HC595 with Arduino UNO but whenever I tried to connect another one with the first shift resistor via cascading connection just like the image shown below (well I didn't use the 10uf capacitor between positive and negative terminal), the first shift register only outputs as desired but the second shift register, connected to a cascading connection, does not seem to work...
Here is the code.
int latchPin = 10; // Latch pin of 74HC595 is connected to Digital pin 5
int clockPin = 11; // Clock pin of 74HC595 is connected to Digital pin 6
int dataPin = 9; // Data pin of 74HC595 is connected to Digital pin 4
byte leds = 0; // Variable to hold the pattern of which LEDs are currently turned on or off
/*
* setup() - this function runs once when you turn your Arduino on
* We initialize the serial connection with the computer
*/
void setup()
{
// Set all the pins of 74HC595 as OUTPUT
pinMode(latchPin, OUTPUT);
pinMode(dataPin, OUTPUT);
pinMode(clockPin, OUTPUT);
Serial.begin(9600);
}
/*
* loop() - this function runs over and over again
*/
void loop()
{
leds = 0; // Initially turns all the LEDs off, by giving the variable 'leds' the value 0
updateShiftRegister();
delay(500);
for (int i = 0; i <= 16; i++) // Turn all the LEDs ON one by one.
{
bitSet(leds, i); // Set the bit that controls that LED in the variable 'leds'
updateShiftRegister();
delay(500);
}
/* The loop above should repeated 16 times as there are 2 shift resistors, each of them containing 8 and we need to lit up all 16 LEDs*/
}
/*
* updateShiftRegister() - This function sets the latchPin to low, then calls the Arduino function 'shiftOut' to shift out contents of variable 'leds' in the shift register before putting the 'latchPin' high again.
*/
void updateShiftRegister()
{
digitalWrite(latchPin, LOW);
shiftOut(dataPin, clockPin, LSBFIRST, leds);
digitalWrite(latchPin, HIGH);
}
so is it my code or wiring problem?
I have read many articles on internet to make myself get it understood but unfortunately, none of the articles satisfied me.
many thanks for giving me a bit of your precious time...
