[Summary] Code won't load to arduino MEGA. It turns out one string has a "!!!" in it, which prevents the code from loading. The bug only exists in older Arduino board with older bootloaders.
I have this issue: If I upload blink or longer code to my MEGA2560, it works. If I upload a watch dog timer sleep sketch (see below), which is not long, it will hang in the middle of the upload. I have two mega boards and they do this both. I wonder if this has anything to do with the WDT or sleep code. I tested the code on uno and it works fine. I wonder if the arduino abstraction has once again bit my rear or not. I'm sure it's something rather stupid. I later added disabling and reenabling interrupt around the WDT setup but still can't upload to MEGA.
/*
* Sketch for testing sleep mode with wake up on WDT.
* Donal Morrissey - 2011.
*
*/
#include <avr/sleep.h>
#include <avr/power.h>
#include <avr/wdt.h>
#define LED_PIN (13)
volatile int f_wdt=1;
/***************************************************
* Name: ISR(WDT_vect)
*
* Returns: Nothing.
*
* Parameters: None.
*
* Description: Watchdog Interrupt Service. This
* is executed when watchdog timed out.
*
***************************************************/
ISR(WDT_vect)
{
if(f_wdt == 0)
{
f_wdt=1;
}
else
{
Serial.println("WDT Overrun!!!");
}
}
/***************************************************
* Name: enterSleep
*
* Returns: Nothing.
*
* Parameters: None.
*
* Description: Enters the arduino into sleep mode.
*
***************************************************/
void enterSleep(void)
{
set_sleep_mode(SLEEP_MODE_PWR_SAVE); /* EDIT: could also use SLEEP_MODE_PWR_DOWN for lowest power consumption. */
sleep_enable();
/* Now enter sleep mode. */
sleep_mode();
/* The program will continue from here after the WDT timeout*/
sleep_disable(); /* First thing to do is disable sleep. */
/* Re-enable the peripherals. */
power_all_enable();
}
/***************************************************
* Name: setup
*
* Returns: Nothing.
*
* Parameters: None.
*
* Description: Setup for the serial comms and the
* Watch dog timeout.
*
***************************************************/
void setup()
{
Serial.begin(9600);
Serial.println("Initialising...");
delay(100); //Allow for serial print to complete.
pinMode(LED_PIN,OUTPUT);
/*** Setup the WDT ***/
/* Clear the reset flag. */
MCUSR &= ~(1<<WDRF);
/* In order to change WDE or the prescaler, we need to
* set WDCE (This will allow updates for 4 clock cycles).
*/
WDTCSR |= (1<<WDCE) | (1<<WDE);
/* set new watchdog timeout prescaler value */
WDTCSR = 1<<WDP0 | 1<<WDP3; /* 8.0 seconds */
/* Enable the WD interrupt (note no reset). */
WDTCSR |= _BV(WDIE);
Serial.println("Initialisation complete.");
delay(100); //Allow for serial print to complete.
}
/***************************************************
* Name: enterSleep
*
* Returns: Nothing.
*
* Parameters: None.
*
* Description: Main application loop.
*
***************************************************/
void loop()
{
if(f_wdt == 1)
{
/* Toggle the LED */
digitalWrite(LED_PIN, !digitalRead(LED_PIN));
/* Don't forget to clear the flag. */
f_wdt = 0;
/* Re-enter sleep mode. */
enterSleep();
}
else
{
/* Do nothing. */
}
}
2560 doc has this code blurb:
void WDT_off(void)
{
__disable_interrupt();
__watchdog_reset();
/* Clear WDRF in MCUSR */
MCUSR &= ~(1<<WDRF);
/* Write logical one to WDCE and WDE */
/* Keep old prescaler setting to prevent unintentional time-out
*/
WDTCSR |= (1<<WDCE) | (1<<WDE);
/* Turn off WDT */
WDTCSR = 0x00;
__enable_interrupt();
}
I don't know what header to include to define __watchdog_reset().
I also get the core.a exists error once in a while when compiling code.
Log:
C:\Arduino\arduino-1.6.5-r2\hardware\tools\avr/bin/avrdude -CC:\Arduino\arduino-1.6.5-r2\hardware\tools\avr/etc/avrdude.conf -v -patmega2560 -cwiring -PCOM12 -b115200 -D -Uflash:w:C:\Users\ZENGQI~1\AppData\Local\Temp\build731221977736597301.tmp/WDT_sleep_sample.cpp.hex:i
avrdude: Version 6.0.1, compiled on Apr 15 2015 at 19:59:58
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2009 Joerg Wunsch
System wide configuration file is "C:\Arduino\arduino-1.6.5-r2\hardware\tools\avr/etc/avrdude.conf"
Using Port : COM12
Using Programmer : wiring
Overriding Baud Rate : 115200
AVR Part : ATmega2560
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PA0
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
eeprom 65 10 8 0 no 4096 8 0 9000 9000 0x00 0x00
flash 65 10 256 0 yes 262144 256 1024 4500 4500 0x00 0x00
lfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
hfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
efuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
lock 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00
Programmer Type : Wiring
Description : Wiring
Programmer Model: AVRISP
Hardware Version: 15
Firmware Version Master : 2.10
Vtarget : 0.0 V
SCK period : 43.5 us
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.01s
avrdude: Device signature = 0x1e9801
avrdude: reading input file "C:\Users\ZENGQI~1\AppData\Local\Temp\build731221977736597301.tmp/WDT_sleep_sample.cpp.hex"
avrdude: writing flash (3342 bytes):
Writing | ##########################################avrdude: stk500v2_ReceiveMessage(): timeout
(at least as an interim measure)