#include <SPI.h>
#include <RWM.h>

RWM rwm = RWM();

byte num_channels = 1;                // Number of channels to sample (can be 1, 2, or 4)
unsigned long samp_interval = 10;     // Sampling interval in milliseconds (can range from 10 to 16,777,215)
int buffer[1];                        // Data buffer to store samples temporarily (size should match num_channels)

unsigned long address, next_samp_time, num_lines;


void setup() {
  byte value;
 
  pinMode(2, OUTPUT);    digitalWrite(2, LOW);
  pinMode(3, OUTPUT);    digitalWrite(3, LOW);
  pinMode(4, OUTPUT);    digitalWrite(4, LOW);
   
  Serial.begin(9600);
  value = rwm.EEPROMreadByte(0x1FFFC);
  if ((value!=255) && (value!=0)) {
    digitalWrite(2, HIGH);   // set pin 2 high  --- indicates error
    Serial.println("EEPROM is not blank.  You should download the data and clear the EEPROM before trying to log more data.");
    while (1) {}
    
  }
  if ((num_channels!=1) && (num_channels!=2) && (num_channels!=4)) {
    digitalWrite(2, HIGH);   // set pin 2 high  --- indicates error 
    Serial.println("The number of channels to log must be 1, 2, or 4.");
    while (1) {}
  }
  if ((samp_interval<10) || (samp_interval>16777215)) {
    digitalWrite(2, HIGH);   // set pin 2 high --- indicates error    
    Serial.println("The sampling interval must be between 10ms and 16,777,215ms.");
    while (1) {}
  }
  if (value==255) {
    digitalWrite(3, HIGH);   // set pin 3 high --- indicates ready to go
    rwm.EEPROMwriteByte(0x1FFFC, 0);
    Serial.println("The datalogger will start logging data the next time it is powered up.");
    while (1) {}
  }
  
  rwm.EEPROMwriteByte(0x1FFFC, num_channels);
  rwm.EEPROMwriteByte(0x1FFFD, lowByte(word(samp_interval&0xFFFF)));
  rwm.EEPROMwriteByte(0x1FFFE, highByte(word(samp_interval&0xFFFF)));
  rwm.EEPROMwriteByte(0x1FFFF, byte(samp_interval>>16));
  address = 0;
  next_samp_time = millis() + samp_interval;
  num_lines = 65534/num_channels;
  
 
}

void loop() {
  byte i;
  unsigned long time;


  time = millis();
  if (time>next_samp_time) {
    for (i = 0; i<num_channels; i++)
      buffer[i] = rwm.ADCreadChannel(i);
    rwm.EEPROMwriteInt(address, buffer[0]);
    ++address;
    next_samp_time = time + samp_interval;
  }
   
   /// Check if EEPROM is full
   if (address > num_lines){
      digitalWrite(4, LOW);  // turn off pin 4 when EPROM is full
   } else {
     digitalWrite(4, HIGH);   // set Pin 4 on -indicates actively logging
  }
     

}