// Mega2560 Serial1 JSON to ESP2866
//https://forum.arduino.cc/t/arduino-mega-to-esp8266-communication-via-tx-rx/857016/67

// download SafeString V4.1.0+ library from the Arduino Library manager or from
// https://www.forward.com.au/pfod/ArduinoProgramming/SafeString/index.html

#include <ArduinoJson.h>
#include "SerialComs.h"

// use Mega HardwareSerial Serial1
#define toESP Serial1

#define SAMPLES 20 //Number of samples you want to take everytime you loop

// do the reads in setup if you need to do initial reads
int voltageValue;// = analogRead(A0); //From Sunnybuddy output
int ADCValue;// = analogRead(A1); // From Sensor output
int Vr_value;// = analogRead(A2); // From solar panel
int sensorValue;// = analogRead(A3); // From solar panel
float R1 = 470000; // These 2 resistors build up a Voltage divider to bring down PV voltage down to Arduino operating voltage
float R2 = 100000;

// sendLineLength, receiveLineLength
SerialComs coms(250, 10);  // 250 sendlength, 10 receive (nothing received)
// sendLineLength must be > json string
// but must be < 250 so whole line fits in Serial RX buffer
// receiveLineLength must match other sides sendLineLength
// sendLineLength must match other sides receiveLineLength

StaticJsonDocument<1000> doc; // allocates on stack

void setup() {
  Serial.begin(115200);
  for (int i = 10; i > 0; i--) {
    Serial.print(' '); Serial.print(i);
    delay(500);
  }
  Serial.println();
  SafeString::setOutput(Serial); // enable error msgs and debug
  toESP.begin(9600);   // Initialize the "link" serial port

  if (!coms.connect(toESP)) {
    while (1) {
      Serial.println(F("Out of memory"));
      delay(3000);
    }
  }
  Serial.println(F("Mega2560 Setup finished."));
  Serial.println(F("waiting for connection."));
  // if you want a startup msg
  //coms.textToSend = F("StartedUp"); // let the other side know we have just booted up
}

// The Atmel datasheets for the micro-processors Arduino uses for Uno/Mega2560 advises
// the user that the first A/D reading after changing the reference voltage may be incorrect and should be ignored.
// 20 samples takes about 2mS to complete
int readAnalog(int Apin) {
  long analogValue = analogRead(Apin); // allow for sum
  // discard the first one
  analogValue = 0;
  for (int i = 0; i < SAMPLES; i++) {
    analogValue = analogValue + analogRead(Apin);
  }
  analogValue = analogValue / SAMPLES;
  return (int)analogValue;
}

// the 4 adc reads in this loop take about 10mS
// comd takes about 1sec to send 100chars at 9600 baud
void loop() {
  coms.sendAndReceive(); // must do this every loop

  //Reading PV module input status
  // reading current from A2/supply voltage and calcultating average value
  int Vr_valueavg = readAnalog(A2);
  float Vr = Vr_valueavg * (5.0 / 1023.0);
  float Vin = Vr * ((R1 + R2) / R2);

  // reading current from A3/supply current and calcultating average value
  int sensorValueavg = readAnalog(A3);
  float voltage_sensor = sensorValueavg * (5.0 / 1023.0);
  float Iin = (voltage_sensor - 2.5) / 0.185;

  float Pin = Vin * Iin;

  // reading voltage from A0/output voltage and calcultating average value,
  // we are interested in value above 3.8V as it is our rated battery charging voltage
  int VoltageValueavg = readAnalog(A0);
  float Vout = VoltageValueavg * (5.0 / 1023.0);

  // reading current from A1/output current and calcultating average value
  int ADCValueavg = readAnalog(A1);
  float voltage_ADC = ADCValueavg * (5.0 / 1023.0);
  float Iout = (voltage_ADC - 2.5) / 0.1;

  float Pout = Vout * Iout;

  //getting data from sensors
  doc["Vin"] = Vin;
  doc["Iin"] = Iin;
  doc["Pin"] = Pin;
  doc["Vout"] = Vout;
  doc["Iout"] = Iout;
  doc["Pout"] = Pout;
  if (coms.textToSend.isEmpty()) {
    serializeJson(doc, coms.textToSend);
    // Serial.println(coms.textToSend);
  }
}