/*
This is the base code used for the PCB designed in this project. It does not include
buttons to update WiFi credentials.
*/

//Code for master ATMEGA328P-AU

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <OneWire.h>
#include <DallasTemperature.h>
//const definitions
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET 4
#define ONE_WIRE_BUS 2

//Global definitions
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
String sDat;
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

void setup() {
  sensors.begin();
  display.begin(SSD1306_SWITCHCAPVCC,0x3C);
  display.clearDisplay();
  display.display();
  SPI.begin();
  SPI.setClockDivider(SPI_CLOCK_DIV8);//2MHz
  digitalWrite(SS,HIGH);//Set SlaveSelect HIGH so master doesn't connect to slave
}

void loop() {
  sensors.requestTemperatures();
  sDat=String(sensors.getTempCByIndex(0));
  drawChar(sDat + " degC");
  byte mSend, mReceive;
  digitalWrite(SS,LOW);//Start communication w/ slave
  mReceive=SPI.transfer(mSend=sensors.getTempCByIndex(0));//Send the mSend val to slave also receives val
}

void drawChar(String str){
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.cp437(true);
  display.print(str);
  display.display();
}
/******************************************************************************************
 * Code for slave ATMEGA328P-AU
 ******************************************************************************************
 */
#include <SPI.h>
volatile bool received;
volatile byte sReceived, sSend;

static String AP="CroHome";//AP name
static String PASS="allourbirthdays";// AP Password
static String API="4UXAGXPGI3TFYCIY";
static String HOST="api.thingspeak.com";
static String PORT="80";
int cTrueCommand, cTimeCommand;
bool found=false;
int sVal=1;

void setup() {
  //ESP8266 setup
  Serial.begin(115200);
  sendCommand("AT+RST",5,"OK");
  sendCommand("AT",5,"OK");
  sendCommand("AT+CWMODE=1",5,"OK");
  String cmd=F("AT+CWJAP=\"");
  cmd+=AP;
  cmd+=F("\",\"");
  cmd+=PASS;
  cmd+=F("\"");
  sendCommand(cmd,20,"OK");

  //SPI setup
  pinMode(MISO,OUTPUT);//Sets miso as OUTPUT (Have to send data to Master IN)
  SPCR|=_BV(SPE);//Turn on SPI in slave mode
  received=false;
  SPI.attachInterrupt();//Interrupt ON for SPI communication
}

void loop() {
  if(received){
    byte sByte=sReceived;//Integer data in F ready
    if(sByte!=185 && sByte!=-196){//avoid temp sensor error values
      String strSByte=String(sByte);
      String getDat="GET /update?api_key="+API+"&field1="+strSByte;
      sendCommand("AT+CIPMUX=1",5,"OK");
      sendCommand("AT+CIPSTART=0,\"TCP\",\""+HOST+"\","+PORT,15,"OK");
      sendCommand("AT+CIPSEND=0,"+String(getDat.length()+4),4,">");
      Serial.println(getDat);
      cTrueCommand++;
      sendCommand("AT+CIPCLOSE=0",5,"OK");
    }
  }
}

ISR(SPI_STC_vect){
  sReceived=SPDR;
  received=true;
}

void sendCommand(String command, int maxTime, char readReplay[]){//Send data to ESP8266
  while(cTimeCommand < (maxTime*1)){
    Serial.println(command);//at+cipsend
    if(Serial.find(readReplay)){
      found=true;
      break;
    }
    cTimeCommand++;
  }
  if(found){
    cTrueCommand++;
    cTimeCommand=0;
  }
  else{
    cTrueCommand=0;
    cTimeCommand=0;
  }
  found=false;
}