Why does delay() cause my arduino to reset? - arduino

Question

I am using an Arduino Uno, connected to a USB shield, a RFID shield(adafruit PN532), an LCD, EEPROM(24AA256) and a RTC module(DS1307). I will not post my code here because it is too large and it is separated in multiple files.
In my program, I realize that if my programs enters a certain functions, after entering function after function, if I use a delay() at the end of the function I am currently in, the arduino resets. An example of what I mean is below.
void a() { b(); }
void b() { c(); }
void c() { d(); }
void d()
{
lcd_string("Testing", 0x80);
delay(2000); <---- Arduino resets at the delay here
}
At first, I thought it was because my dynamic memory was at 80%, and when I compiled, they said the Arduino might have some stability issues. So I modified my code such that my dynamic memory is now 57%. Problem still exist.
I thought maybe the delay() function has some overflow or something, so I tried replacing the delay with the following code.
unsigned long timing;
timing = millis();
timing += 2000;
while(millis() < timing);
The Arduino still resets.
Next, I thought maybe because my arduino is connected to my PC, some serial pin might have been causing the reset, so I used an external Power to power up the arduino and disconnected the USB. The arduino still resets.
Next, I thought maybe Timer1 might have been crashing with the delay() function, although the delay function uses Timer0 so I disabled my Timer1 . The arduino still resets.
Is there any other possibilities that I am missing out? My program storage space is at 69% which I believe shouldn't be an issue.
Edit
Here is my code for Timer1 ISR
ISR(TIMER1_OVF_vect)
{
TCCR1A = 0;
TCCR1B = 0;
TCNT1 = 0;
OCR1A = 34286;// = (16*10^6) / (1*1024) - 1 (must be <65536)
TCCR1B |= (1 << CS12);
// enable timer compare interrupt
TIMSK1 |= (1 << TOIE1);
triggered = 1;
}
Any other interrupt of flags used are in the library header files.
I am using the following external libraries
USB Host shield library 2.0
Adafruit PN532 master

Answer 1

A little sample to come close to RAM corruption ...
#define MEM_PER_LEVEL 50
#define TRY_TO_SURVIVE 10
void KillMe(int level) {
byte dummy[MEM_PER_LEVEL];
for ( byte i = 0; i < MEM_PER_LEVEL; i++)
dummy[i]= i;
Serial.println(level);
delay(1000); // not sure why this would hurt more than others
if (level < TRY_TO_SURVIVE) KillMe(level+1);
for ( byte i = 0; i < MEM_PER_LEVEL; i++) {
if (dummy[i] != i) {
Serial.println(F("corruption happened"));
while(1) {} // HALT
}
}
if (level == 0)
Serial.println(F("survived"));
}
void setup() {
Serial.begin(9600);
KillMe(0);
}
void loop() { }

Answer 2

I had the same problem - wherever I put a delay in my setup function the Arduino would restart.
For me, the problem was an instance of SoftwareSerial with invalid pin numbers.
SoftwareSerial mySerial(30, 31);
Anyone else landing on this question should check their pin numbers are appropriate for the board they're targeting. Not sure why the crash only happens if a delay is called, would be interested if anyone has insight into this!