// Pin definitions
const int dataPin = 8;    // Connects to DI on CD4094BE
const int clockPin = 9;   // Connects to CP on CD4094BE
const int strobePin = 10; // Connects to STROBE on CD4094BE
const int oePin = 11;

void setup() {
  // Set the pins as outputs
  pinMode(dataPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(strobePin, OUTPUT);
  pinMode(oePin, OUTPUT);
  Serial.begin(115200);
  digitalWrite(oePin, HIGH);

}

void loop() {
  // Count from 0 to 255
  for (int i = 0; i < 256; i++) {
    // Send the binary representation of 'i' to the shift register
    sendTo4094(i);
    Serial.println(i);
    delay(1000); // Wait for half a second
  }
}

// Function to send data to CD4094BE
void sendTo4094(int data) {
  digitalWrite(strobePin, LOW); // Prepare for data input

  for (int i = 0; i < 8; i++) {
    // Send each bit from MSB to LSB
    digitalWrite(dataPin, (data & (1 << (7 - i))) ? HIGH : LOW);
    
    // Toggle clock pin to shift in data
    digitalWrite(clockPin, HIGH);
    digitalWrite(clockPin, LOW);
  }

  // Latch the data by toggling the strobe pin
  digitalWrite(strobePin, HIGH);
  digitalWrite(strobePin, LOW);
}


sketch.ino

diagram.json

cd4094

cd4094.chip.json

// Wokwi Custom Chip - For docs and examples see:
// https://docs.wokwi.com/chips-api/getting-started
//
// SPDX-License-Identifier: MIT
// Copyright 2023 GC1 CEO

#include "wokwi-api.h"
#include <stdio.h>
#include <stdlib.h>


const char* pin_names_Q [8] = { 
  "Q1", "Q2", "Q3", "Q4",
  "Q5", "Q6", "Q7", "Q8"
};

typedef struct {
  pin_t VSS;
  pin_t VDD;
  pin_t CLK;
  pin_t DATA;
  pin_t STR;
  pin_t QS;
  pin_t QSN;
  pin_t Q[8];
  pin_t OE;
  uint8_t bit;
  uint8_t reg;
} chip_state_t;

bool power_chk(void *data)
{
  chip_state_t *chip = (chip_state_t*)data;

  return pin_read(chip->VDD) && !pin_read(chip->VSS);
}

void clk_change(void *user_data, pin_t pin, uint32_t value) {

  chip_state_t *chip = (chip_state_t*)user_data;

  if (!power_chk(chip))
  {
    for (int i = 1; i < 8; i++)
    {
      pin_write(chip->Q[i], 0);
    }
    
    printf("no power\n");
    return;
  }

  uint8_t state = pin_read(chip->DATA);
  printf("%i", state);

  if (state) 
  {
    chip->reg |= (1 << chip->bit);
  }
  else
  {
    chip->reg &= ~(1 << chip->bit);
  }

  if (chip->bit == 7) {
    printf("\n");
  }

  chip->bit = chip->bit < 7 ? chip->bit + 1 : 0;
}

void strobe_change(void *user_data, pin_t pin, uint32_t value) {
  chip_state_t *chip = (chip_state_t*)user_data;
  for (int i = 1; i <= 8; i++)
  {
    pin_write(chip->Q[i], (chip->reg >> i) & 1);
  }
}

void chip_init() {
 
  chip_state_t *chip = (chip_state_t*)malloc(sizeof(chip_state_t));

  chip->VDD = pin_init("VDD", INPUT);
  chip->VSS = pin_init("VSS", INPUT);
  chip->CLK = pin_init("CLK", INPUT);
  chip->OE = pin_init("OE", INPUT);
  chip->DATA = pin_init("DATA", INPUT);
  chip->STR = pin_init("STR", INPUT);

  for (int i = 1; i <= 8; i++)
  {
    chip->Q[i] = pin_init(pin_names_Q[i], OUTPUT);
  }

  const pin_watch_config_t clk_watch = {
    .edge = RISING,
    .pin_change = clk_change,
    .user_data = chip,
  };

  pin_watch(chip->CLK, &clk_watch);

  const pin_watch_config_t strobe_watch = {
    .edge = RISING,
    .pin_change = strobe_change,
    .user_data = chip,
  };

  pin_watch(chip->STR, &strobe_watch);
  printf("Hello I'm the CD4094 custom chip.");
  
}
