Raspberry Pi RTC WatchDog HAT

Introduction

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

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

Python example

cd ~/RTC_WatchDog_HAT/RTC/python/examples/
sudo python main.py

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:

Documentation

• Schematic
  
• MAX705 Datasheet
  
• DS3231 Datasheet
  

Demo codes

• Demo Codes
  

To：

Dear Customers, There may be a lag of several hours before we could process your order, depending on the time difference between your location and ours. Sincerely hoping your understanding!

Email(support)

services01@spotpear.com