RTC WatchDog HAT

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RTC WatchDog HAT
RTC WatchDog HAT
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Primary Attribute
Category: Expansions, Raspberry Pi
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Brand: Waveshare
Website
International: Website
Chinese: 官网
Onboard Interfaces
RPi USB
Related Products

Introduction

RTC WatchDog HAT For Raspberry Pi, Auto Reset, High Precision RTC

More

RTC WatchDog HAT

  • MAX705 monitoring circuit with auto reset function
  • Incorporates DS3231SN high precision RTC chip, with backup battery holder
  • Reset pin selection for swiching watchdog
  • Indicator for watchdog output warning

How to use

RTC

Open a terminal and run the following command to download the codes

wget https://www.waveshare.com/w/upload/b/bd/RTC_WatchDog_HAT.zip
zip RTC_WatchDog_HAT.zip
sudo chmod 777 -R RTC_WatchDog_HAT
cd RTC_WatchDog_HAT/RTC
C examples
cd ~/RTC_WatchDog_HAT/RTC/c/
make clean
make 
sudo ./main
RTC WatchDog HAT 1.png
Python example
cd ~/RTC_WatchDog_HAT/RTC/python/examples/
sudo python main.py
RTC WatchDog HAT 2.png

WatchDog

In the WatchDog example, it feeds the watchdog chip if the D4 pin toggle. If the watchdog doesn't be feed in T time, it will cut off the power and the voltage falls to 1.25V, in this case, the MAX705 chip will reset and restart the power. About the time T:

T = 0.7*R*C+1.6s
R is default 5.1M, and C is default 44uF
Tge default delay time is 157.08s ±6%

RC are set in the board:

RTC-WatchDog-HAT-3.jpg

Support

If you require technical support, please go to the Support page and open a tickets.