README.md

diagram.json

lcd-driver

lcd-driver.chip.json

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

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

// Enums
enum {
  LCD_MODE_CMD = 0,
  LCD_MODE_DAT
};

// Pin config
typedef struct {
  const char* pName;
  uint32_t mode;
  pin_t pin;
} pinConfig_t;

typedef struct {
  // TODO!
} chip_state_t;

// LCD Pin config.
pinConfig_t lcdPins[] = {
  {"RS", OUTPUT_LOW, (pin_t)NULL},
  {"RW", OUTPUT_LOW, (pin_t)NULL},
  {"EN", OUTPUT_LOW, (pin_t)NULL},
  {"D0", OUTPUT_LOW, (pin_t)NULL},
  {"D1", OUTPUT_LOW, (pin_t)NULL},
  {"D2", OUTPUT_LOW, (pin_t)NULL},
  {"D3", OUTPUT_LOW, (pin_t)NULL},
  {"D4", OUTPUT_LOW, (pin_t)NULL},
  {"D5", OUTPUT_LOW, (pin_t)NULL},
  {"D6", OUTPUT_LOW, (pin_t)NULL},
  {"D7", OUTPUT_LOW, (pin_t)NULL},
  {"BL", OUTPUT_HIGH, (pin_t)NULL}
};

void setByte(uint8_t byte) {
  // Set a byte on pins D0 to D7.

  // D0 (Least Significant Bit)
  pin_write(lcdPins[3].pin, (byte & 0x01) ? HIGH : LOW);
  // D1
  pin_write(lcdPins[4].pin, (byte & 0x02) ? HIGH : LOW);
  // D2
  pin_write(lcdPins[5].pin, (byte & 0x04) ? HIGH : LOW);
  // D3
  pin_write(lcdPins[6].pin, (byte & 0x08) ? HIGH : LOW);
  // D4
  pin_write(lcdPins[7].pin, (byte & 0x10) ? HIGH : LOW);
  // D5
  pin_write(lcdPins[8].pin, (byte & 0x20) ? HIGH : LOW);
  // D6
  pin_write(lcdPins[9].pin, (byte & 0x40) ? HIGH : LOW);
  // D7 (Most Significant Bit)
  pin_write(lcdPins[10].pin, (byte & 0x80) ? HIGH : LOW);
}

void send(uint8_t mode) {
  // Set mode.
  if(mode == LCD_MODE_CMD) {
    pin_write(lcdPins[0].pin, LOW);
  } else if(mode == LCD_MODE_DAT) {
    pin_write(lcdPins[0].pin, HIGH);
  }

  // Make disp ack.
  pin_write(lcdPins[2].pin, HIGH);
  pin_write(lcdPins[2].pin, LOW);
}

void writeByte(uint8_t byte, uint8_t mode) {
  // Set byte
  setByte(byte);

  // Write
  send(mode);
}

void sendString(const char* str) {
  int strL = strlen(str) - 1;
  for(int i=0; i<strL; i++) {
    writeByte(str[i], LCD_MODE_DAT);
  }
}

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

  // Configure pins
  for(int i=0; i<sizeof(lcdPins); i++) {
    lcdPins[i].pin = pin_init(lcdPins[i].pName, lcdPins[i].mode);
  }

  // En
  writeByte(0x0F, LCD_MODE_CMD);
  sendString("Hello, Wokwi!");
  
  printf("Hello from custom chip!\n");
}
