User Manual

for(i=0;i<8;i++){

digitalWrite(SDI, ((byte & (0x80 >> i)) > 0)); // Use the for loop to count 8

times in cycle, and write a 1-bit data to the SDI each time. The data is a result of the

AND operation. (0x80 >> i) is to implement the operation from left to right by bit, so

each time one of the eight bits in byte (0000 0001).

pulse(SRCLK); // the shift register generates a rising edge pulse, and data in

DS will shift to the shift register.

} // This part is to assign the data in byte to SDI(DS) by bits, thus when the shift

}

void init(void): // Set DS, ST_CP, SH_CP as output, and low level as the initial state

for(i=0;i<8;i++){

SIPO(LED[i]); // Assign the value in the LED[i] array to SDI(DS). When i=1,

LED[0]=0x01 shifts to the shift register.

pulse(RCLK); // RCLK (ST_CP) generates a rising edge pulse, and the data of the

shift register is stored in the RCLK (ST_CP) storage register, and output at Q0-Q7.

delay(150);

} After 8 cycles, Q0-Q7 will output 0x01 to 0x10 in sequence, that is to light up the

LEDs connected to Q0-Q7 in turn.

Sketch in later part not explained here is to light up 8 LEDs together, and dim them;

then light up LEDs connected to Q7-Q0 one by one, and all 8 LEDs light up, dim in the

end. Thus, a cycle completes. You can observe the LEDs’ state.

For Python users:

Step 2: Get into the folder of the code

cd /home/pi/SunFounder_Super_Kit_V3.0_for_Raspberry_Pi/Python

Step 3: Run

sudo python 13_74HC595_LED.py

Code Explanation

LED0 = [0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80] # Define some LED blinking

modes. Convert hexadecimal value to binary value will be more intuitionistic. For

instance, 0x01 is binary 00000001, meaning the last LED lighting up; 0x80 is binary

10000000, representing the first LED lighting up.

LED1 = [0x01,0x03,0x07,0x0f,0x1f,0x3f,0x7f,0xff] # blink mode 1

LED2 = [0x01,0x05,0x15,0x55,0xb5,0xf5,0xfb,0xff] # blink mode 2

LED3 = [0x02,0x03,0x0b,0x0f,0x2f,0x3f,0xbf,0xff] # blink mode 3

# Shift the data to 74HC595

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