The 74HC4017 is a high-speed CMOS device that serves as a 5-stage Johnson decade counter with 10 decoded outputs. It is designed to produce a sequence of output pulses, one at a time, for every input pulse received. This component is widely used in digital logic circuits for creating LED chasers, frequency dividers, and various timing and counting applications.
This circuit includes a decade counter (74HC4017) that likely sequences through outputs based on pushbutton inputs. A BC547 transistor is used to drive an LED, indicating one of the counter's states. Diodes and resistors are included for current direction control and limiting, respectively.
Open Project in Cirkit Designer
This circuit uses a 74HC4017 decade counter to control the sequence of an LED array. Pushbuttons are used to interact with the counter, advancing or resetting the sequence, while a BC547 transistor is used to switch an LED on and off. Diodes are included to prevent reverse current, ensuring proper operation of the counter.
Open Project in Cirkit Designer
This circuit uses a Teensy 4.0 microcontroller to control a MAX7219 LED driver, which in turn drives three 7-segment displays. The microcontroller runs code to display numbers from 0 to 999 on the 7-segment displays, with the SN74AHCT125N buffer providing signal integrity and the necessary capacitors and resistors ensuring stable operation.
Open Project in Cirkit Designer
This circuit uses a 74HC595 shift register to control multiple LEDs via a common ground configuration, with a microcontroller providing serial data input. It includes decoupling capacitors for stability and a 12-Bit DAC, potentially for analog signal generation or reference voltage application.
Open Project in Cirkit Designer| Pin Number | Name | Description |
|---|---|---|
| 1 | Q5 | Output 5 |
| 2 | Q1 | Output 1 |
| 3 | Q0 | Output 0 |
| 4 | Q2 | Output 2 |
| 5 | Q6 | Output 6 |
| 6 | Q7 | Output 7 |
| 7 | Q3 | Output 3 |
| 8 | GND | Ground |
| 9 | Q8 | Output 8 |
| 10 | Q4 | Output 4 |
| 11 | Q9 | Output 9 |
| 12 | CO | Carry Out (for cascading) |
| 13 | MR | Master Reset (active high) |
| 14 | CLOCK INHIBIT | Clock Inhibit (active high) |
| 15 | CLOCK | Clock Input (rising edge triggered) |
| 16 | Vcc | Positive Supply Voltage |
// Define the output pins connected to the 74HC4017
int outputs[] = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
void setup() {
// Set all the output pins as outputs
for (int i = 0; i < 10; i++) {
pinMode(outputs[i], OUTPUT);
}
// Set the clock pin as output
pinMode(12, OUTPUT);
}
void loop() {
// Send a clock pulse to the 74HC4017
digitalWrite(12, HIGH);
delay(10); // Short delay to ensure the clock pulse is registered
digitalWrite(12, LOW);
delay(500); // Delay between each pulse to control the speed of the LED chaser
}
Q: Can I use the 74HC4017 at a voltage lower than 2V? A: No, the device is not guaranteed to function correctly below its minimum rated supply voltage.
Q: How can I increase the number of outputs beyond 10? A: You can cascade multiple 74HC4017 counters by connecting the CO pin of the first to the CLOCK pin of the next.
Q: Is it necessary to use all the outputs? A: No, you can leave unused outputs unconnected. However, it is good practice to ensure they are not floating.
Q: Can the 74HC4017 be used with an Arduino? A: Yes, the 74HC4017 can be easily interfaced with an Arduino or any other microcontroller platform.