An independent timer module usually incorporated into the same chip as a uProcessor which resets the processor after a certain length of time. The idea is that during usual operation the code running should always be able to reset the watchdog timer before the watchdog resets the processor. If the ...

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1answer
51 views

doubt about using both watchdog timers in pic

I want to use both the conventional WDT and deep sleep WDT. 1.I will be using WDT to prevent any code lock cases if any. 2.And the other after entering deep sleep mode to wake up periodically in ...
1
vote
1answer
81 views

Watchdog timer not being called in sleep mode

On an ATMega328p, I'm trying to setup a program that counts 1 second intervals via the watchdog timer, even when the chip is in sleep mode. A button interrupt puts the chip into sleep mode. The ...
2
votes
2answers
99 views

Reporting crashes/resets in Embedded Systems(8 bit)

I'm using PIC controllers, and I have used watch dog timers to trigger a reset in case of the s/w gets stuck somewhere, and also to support in case of severe hardware crashes. I think that resetting ...
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vote
3answers
114 views

External watchdog reset for AVR required

I had a circuit with ATmega644PA and use internal watchdog timer to bring the controller from a hang state to known by a reset. but my code still hangs in some loop ...
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1answer
230 views

PIC:How to enable watch dog timer in PIC18F67K22 controller? [closed]

I am using PIC18F67K22 controller in my circuit. I don't know how to enable or configure Watch Dog Timers(WDT) in my controller. Any one have explanation with some demo code of Enable Watch Dog Timer ...
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vote
1answer
88 views

Choosing values of resistive divider, versus pullup resistor value

I have a slight Catch-22 with my circuit portion shown below. The ADM6320 is, among other things, an undervoltage detector with factory threshold of 2.93 V (thus Reset output pin toggles when VCC ...
6
votes
2answers
1k views

Use AVR Watchdog like normal ISR

I'm trying to wrap my head around the watchdog timer on the ATTinyX5 series. So things I've read made it seem like you could use it for making the program do something specific ever N seconds but ...
1
vote
1answer
140 views

To get rid of useless redundancy--do I realy need a voltage supervisor?

I am using a voltage supervisor from MAXIAM(MAX7634A). It monitors VCC_3V3 and VCC_-3V3(I use LM358 to make it a positive one).Power supply distribution is shown below: VCC_3V3: stm32f103 EMP570T144 ...
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1answer
156 views

what is logic contention when using a voltage supervisor?

I am using a voltage supervisor from MAXIAM (MAX6734A).I am confused about design notes in page 11. so,what is logic contention? the uP that I want to monitor is STM32F103ZET6.I read its ...
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votes
2answers
798 views

Arduino w/ Atmega328: can't clear the watchdog

I'm using the onboard software watchdog facility of an Atmega328 like documented here. My purpose is to limit to 2 seconds the execution of a portion of code that could lead to endless computation. ...
2
votes
1answer
201 views

Fail to verify if watch dog timer works properly

I wrote a simple watch dog timer program. First I light up a LED, and I want to see if watch dog timer will reset the chip and the LED would be turned off(I didn't feed the watch dog). ...
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vote
1answer
413 views

How to use watchdog timer in ATmega128

I am working with an ATmega128 and need to reset the microcontroller after some 10 seconds has passed and the user has not interacted with microcontroller. As an example when the user has not pressed ...
3
votes
2answers
276 views

Low power, cheap, long timeout, watchdog circuit

I need a circuit to act as a watchdog to a micro (which is not powered (instead of in a sleep mode)most of the time). it needs to be low power (< ~4uA) and non-programmable. So no I2C RTCs or ...
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2answers
205 views

PIC: Watchdog timer off by a factor of 4

I have a PIC16 (datasheet here) for which I use the watchdog timer. I configure the watchdog timer as follows: WDTCONbits.WDTPS = 0b01110; According to page 105 ...
4
votes
2answers
628 views

How to debug reset caused by WDTCTL security key violation in MSP430F1611?

I'm working on a sensor project which uses TelosB based on MSP430F1611 running TinyOS. My program is reset some time after boot up. After the PUC reset, IFG1 is found with WDTIFG bit set, indicating ...
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votes
3answers
156 views

Effective use of output signal of a watchdog timer

Subsequent to my previous question regarding watchdog timers, I am interested in deciding the RESULT of such a watchdog: Assume I add a generic external watchdog timer to my circuit. If not toggled ...
6
votes
3answers
716 views

Which of these approaches for a watchdog timer?

I recently learned about watchdog timers, and am trying to implement one for my circuit for the purpose of resetting my (AVR) microcontroller if it hangs (i.e., doesn't respond to the watchdog). ...
2
votes
2answers
152 views

Watchdog Signature in Flash memory or RAM?

We used to use Watchdog signatures in our control applications. Basically we used to allocate a reserved memory in RAM(uninitialized) and used to store the watchdog signatures. On power on, the ...
3
votes
2answers
652 views

74123 vs 4538 as watchdog timer

I want to use a retriggerable monostable multivibrator as a hardware watchdog. This is for an amateur satellite project so I need to use basic rad hard logic chips (as opposed to more sophisticated ...
3
votes
2answers
1k views

Watchdog reset using C32 v2.00 compiler

Compiling an existing PIC32 project using the v2.00 C compiler produces a continual watchdog reset. This problem does not appear using the previous v1.12 compiler. Changing the watchdog postscaler ...
7
votes
2answers
329 views

Microcontroller's watchdog

Can anyone explain a little more about watchdogs, specifically in the circuitry level? If there is some kind of problem in the chip, how can I guarantee that it will be kept running? It is ...
4
votes
3answers
2k views

ARM watchdog reset

I have an MP3 development board I picked up from sparkfun that runs off the LPC2148 ARM processor. In looking through the code, I see a function to force a watchdog reset. My question is, how do you ...