Add character LCD support to emonesp

lcd.cpp

#include <LiquidCrystal.h>
#include <ESP8266Wifi.h>
#include "lcd.h"

static LiquidCrystal lcd(4, 5, 12, 13, 14, 16);

#define MAXCT 4
static int _ctdata[MAXCT];
static int _vrms;

static const char LCDCHAR_HOUSE[8] PROGMEM = {
  0b00000,
  0b00100,
  0b01110,
  0b11111,
  0b01110,
  0b01010,
  0b01010,
  0b00000
};

static const char LCDCHAR_SUN[8] PROGMEM = {
  0b00100,
  0b10101,
  0b01110,
  0b01010,
  0b11011,
  0b01110,
  0b10101,
  0b00100
};

static const char LCDCHAR_ANTENNA[8] PROGMEM = {
  0b00000,
  0b11111,
  0b10101,
  0b01110,
  0b00100,
  0b00100,
  0b00100,
  0b00000
};

static const char LCDCHAR_WIFI_0[8] PROGMEM = {
  0b00000,
  0b00000,
  0b10001,
  0b01010,
  0b00000,
  0b01010,
  0b10001,
  0b00000
};

static const char LCDCHAR_WIFI_1[8] PROGMEM = {
  0b00000,
  0b00000,
  0b00000,
  0b00000,
  0b00000,
  0b10000,
  0b10000,
  0b00000
};

static const char LCDCHAR_WIFI_2[8] PROGMEM = {
  0b00000,
  0b00000,
  0b00000,
  0b00100,
  0b00100,
  0b10100,
  0b10100,
  0b00000
};

static const char LCDCHAR_WIFI_3[8] PROGMEM = {
  0b00000,
  0b00001,
  0b00001,
  0b00101,
  0b00101,
  0b10101,
  0b10101,
  0b00000
};

static void parseCtInput(String &input)
{
  char *cstr = new char[input.length()+1];
  strcpy(cstr, input.c_str());
  
  // Parse ct1:XXX,ct2:XXX,...,t0:XXX,vrms:XXX
  char *reading = strtok(cstr, ",");
  while (reading != 0)
  {
    char *separator = strchr(reading, ':');
    if (separator != 0)
    {
      int val = atoi(separator+1);
      *separator = '\0';
      if (strncmp(reading, "ct", 2) == 0)
      {
        uint8_t which = reading[2] - '1';
        if (which < MAXCT)
            _ctdata[which] = val;
      }
      else if (strcmp(reading, "vrms") == 0)
        _vrms = val;
    }
    reading = strtok(0, ",");
  }
  
  delete[] cstr;
}

char lcd_getWifiStatus()
{
  byte wifi_status;
  if (WiFi.status() != WL_CONNECTED)
    wifi_status = '\3';
  else
  {
    int rssi = WiFi.RSSI();
    if (rssi > -65)
      wifi_status = '\6';
    else if (rssi > -80)
      wifi_status = '\5';
    else if (rssi > -95)
      wifi_status = '\4';
    else
      wifi_status = ' ';
  }
  return wifi_status;
}

void lcd_updateDisplay()
{
  char buf[17];
  int solar = _ctdata[2] + _ctdata[3];
  int use = _ctdata[0] + _ctdata[1] + solar;

  solar = constrain(solar, -9999, 99999);
  use = constrain(use, -9999, 99999);
  
/* 
 * [H99000W Use 120V]
 * [S 9000W Solar A1]
 */
 snprintf(buf, sizeof(buf), "%c%5dW Use %3dV",
    '\0', use, (_vrms+50) / 100);
  lcd.setCursor(0, 0);
  lcd.write(buf, sizeof(buf)-1);
  
  snprintf(buf, sizeof(buf), "\1%5dW Solar \2%c",
    solar, lcd_getWifiStatus());
  lcd.setCursor(0, 1);
  lcd.write(buf, sizeof(buf)-1);
}

void ICACHE_FLASH_ATTR lcd_createChar(uint8_t idx, PGM_P data)
{
  lcd.command(LCD_SETCGRAMADDR | (idx << 3));
  for (uint8_t i=0; i<8; i++)
    lcd.write(pgm_read_byte(data++));
}

void ICACHE_FLASH_ATTR lcd_setup()
{
  lcd.begin(16, 2);
  lcd_createChar(0, LCDCHAR_HOUSE);
  lcd_createChar(1, LCDCHAR_SUN);
  lcd_createChar(2, LCDCHAR_ANTENNA);
  lcd_createChar(3, LCDCHAR_WIFI_0);
  lcd_createChar(4, LCDCHAR_WIFI_1);
  lcd_createChar(5, LCDCHAR_WIFI_2);
  lcd_createChar(6, LCDCHAR_WIFI_3);

  lcd_updateDisplay();
}

void lcd_publish(String &input)
{
  parseCtInput(input);
  lcd_updateDisplay();  
}

lcd.h

#ifndef _EMONESP_LCD_H
#define _EMONESP_LCD_H

#include <Arduino.h>

void lcd_setup();
void lcd_publish(String &input);

#endif