Super Watchdog HAT with UPS Battery Backup for Raspberry Pi

Overview

UPS battery backup and hardware watchdog in one HAT for Raspberry Pi. The Super Watchdog combines an onboard Li-Ion battery charger, step-up converter, and intelligent power monitor to keep your system running through power outages and automatically recover from software lock-ups.

• Wide power supply: 5V or 10-24V with separate connectors
• Provides 2.5A continuous or 3A peak to Raspberry Pi
• Sockets for two Li-Ion 18650 batteries (breakable for single-battery use)
• Prevents SD Card damage during power outages
• Cycles RPi power after software lock-up
• Enhanced battery charger up to 700mA; charging stoppable via software command
• Battery overheating protection
• Uses only I2C port (address 0x30) — all GPIO pins remain free
• Works with any Raspberry Pi from Zero to 5
• ECCN Code EAR99

Due to space limitations, the Super Watchdog can deliver only 2.5A @5V to the Raspberry Pi. If you are using Raspberry Pi 5, which can consume up to 5A peak, consider the Multichemistry Watchdog UPS for Raspberry Pi 5.

Works with Open Automation Software

Compatible with widely used tools for control and system integration.

INTERFACES AND I/O

DESCRIPTION

The Super Watchdog HAT provides the safety required by any mission-critical Raspberry Pi installation, combining UPS battery backup and an intelligent hardware watchdog in a single compact HAT.

TECHNICAL DETAILS

CARD LAYOUT

MECHANICAL SPECIFICATIONS

ELECTRICAL SPECIFICATIONS

POWER REQUIREMENTS

BATTERY OPERATION

Two 18650 Li-Ion batteries (not provided) can keep the Raspberry Pi running for hours, assuring continuous operation during power outages. When running on battery power, the watchdog processor monitors the battery voltage. To prevent permanent damage due to over-discharging, the processor will cut off power to the Raspberry Pi when the battery drops below 2.8V. A software command is available to monitor the battery voltage. It is strongly recommended that Raspberry Pi performs a self-shutdown when the battery voltage drops below 3.0V.

SELF TEST

The Super Watchdog HAT has onboard hardware to self-check all major functions. The self-check is performed at each power-up. The onboard LED flashes rapidly (5 times per second) if a hardware error is detected, or slowly (1 time per second) to indicate normal functionality. The LED turns on when the watchdog resets the Raspberry Pi, and off when the Raspberry Pi is powered down for a specific time interval.

PUSH-BUTTON

The Super Watchdog HAT has an onboard pushbutton that can be read by the local processor, which in turn can interrupt the Raspberry Pi. The push button can be used to shut down or reset the Raspberry Pi without a keyboard and monitor. A 2-pin jumper parallel to the pushbutton permits installation of the pushbutton at a remote location when the Raspberry Pi is installed in an enclosure.

HARDWARE WATCHDOG

The Super Watchdog HAT includes a hardware watchdog that ensures your system automatically recovers if the Raspberry Pi software becomes unresponsive. The watchdog is disabled at power-up and activates after it receives the first reset command from the Raspberry Pi.

For a full list of watchdog commands, run: wdt -h

COMPATIBILITY

FIRMWARE UPDATE

The onboard microcontroller firmware can be updated in the field. The update tool downloads the latest firmware from Sequent Microsystems' servers and flashes it to the board over I2C.

Running the Update

~$ cd ~/wdt-rpi/update/

~/wdt-rpi/update$ ./update   (or ./update64 for 64-bit OS)

Full instructions including recovery procedures are available at:

https://github.com/SequentMicrosystems/wdt-rpi/tree/master/update/README.md

DOWNLOADS

COMPLIANCE

RoHS and REACH Compliance Declaration

WHAT'S INCLUDED

When you purchase the card you will receive the following items:

1. Super Watchdog HAT for Raspberry Pi

2. Mounting Hardware
	Two M2.5×18mm male-female brass standoffs Two M2.5×5mm brass screws Two M2.5 brass nuts

3. Connector Plugs for Power Inputs
	One 2-pin female mating connector plug for 10-24V power supply One 2-pin female mating connector plug (large) for 5V power supply

QUICK START

1. Plug your card on top of your Raspberry Pi and power up the system from the watchdog.
2. Enable I2C communication on Raspberry Pi using raspi-config.
3. Install the software from GitHub:
   ~$ git clone https://github.com/SequentMicrosystems/wdt-rpi.git

   ~$ cd /home/pi/wdt-rpi

   ~/wdt-rpi$ sudo make install

   ~/wdt-rpi$ wdt

The program will respond with a list of available commands. To read more about the CLI, please refer to the README file. You can also write your own application using the Python Library.