關(guān)于mega328p watchdog

ID:76658 · 發(fā)表于 2015-4-11 11:43

#include <avr/wdt.h>
const int ledPin =  13;    // the number of the LED pin

void setup() {
  wdt_disable();
  Serial.begin(9600);
  Serial.println("System Init OK!");
  pinMode(ledPin, OUTPUT);
  Serial.println("Wait 5 Sec..");
  delay(5000);
  wdt_enable(WDTO_8S);
  Serial.println("Watchdog enabled!");
}

uint8_t timer = 0;
void loop() {
  if (!(millis() % 1000)) {
Serial.print(millis());
Serial.print("--");
timer++;
Serial.println(timer);
digitalWrite(ledPin, digitalRead(ledPin) == 1 ? 0 : 1); delay(1);
  }
  //  wdt_reset();
}

這個(gè)程序無法正常復(fù)位，13引腳的燈一直閃爍。帖子里有人用了：
解決方案：http://www.nongnu.org/avr-libc/u ... _avr__watchdog.html

這里的說明：

Note that for newer devices (ATmega88 and newer, effectively any AVR that has the option to also generate interrupts), the watchdog timer remains active even after a system reset (except a power-on condition), using the fastest prescaler value (approximately 15 ms). It is therefore required to turn off the watchdog early during program startup, the datasheet recommends a sequence like the following:

對于atmega88以及新型號的單片機(jī)(自帶產(chǎn)生中斷的），看門狗可能會在系統(tǒng)復(fù)位之后，依然運(yùn)行(除掉電復(fù)位外）。因此，需要在程序啟動早期，關(guān)閉看門狗。datasheet中推薦插入一段這樣的程序:

#include <stdint.h>
#include <avr/wdt.h>

uint8_t mcusr_mirror __attribute__ ((section (".noinit")));

void get_mcusr(void) \
__attribute__((naked)) \
__attribute__((section(".init3")));
void get_mcusr(void)
{
mcusr_mirror = MCUSR;
MCUSR = 0;
wdt_disable();
}

但是這段程序我加了好幾個(gè)位置都不行，還是不斷地復(fù)位，等反復(fù)閃爍，哪位大神能狗解決這個(gè)問題？

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