Super Watchdog HAT
with Battery Backup
for Raspberry Pi

Regular price $30.00

FEATURES

  • A must for all RPI mission critical installation
  • Cycle RPI power after software lock-up
  • Prevent SD Card damage during power outages
  • Run for hours on Li-Ion 18650 battery
  • On board battery charger, step-up converter and intelligent power monitor
  • Triple power supply jacks: micro USB, USB-C and barrel
  • Provide up to 3.5A/5V power to Raspberry Pi from Li-Ion Battery
  • On board resettable fuse
  • Triple power supply jacks: Barrel, USB2, USB3
  • Command Line Interface
  • Python Library

DESCRIPTION

Raspberry Pi Watchdog and Battery Backup for all Raspberry Pi Boards.

If you use your Raspberry Pi for any mission critical project, you need the Super-Watchdog with battery backup. The watchdog measures only 87mm * 28mm but packs a lot of functions.

The Raspberry Pi Watchdog provides the safety required by mission critical projects, implementing two major functions. It power-cycle the Raspberry Pi in case of software lock-up, resetting not only the Pi but also any peripheral attached to it, and it prevents SD-Card failure in case of power loss, by allowing the Raspberry Pi to shut down itself safely.

The watchdog has a default timeout of 120 seconds. Once installed, if it does not receive a reset from Raspberry Pi within 2 minutes, it cuts the power and restores it after 10 seconds.

Raspberry Pi needs to issue a reset command before the timer on the watchdog expires. The command can be sent either on the I2C port , or by toggling GPIO11 ( Pin 23 on the GPIO connector). The timer period after power up and the active timer period can be set from the command line. The number of resets is stored in flash and can be accessed or cleared from the command line.

COMPATIBILITY

The Raspberry Pi  Watchdog is compatible with all Raspberry version B+, 2, 3, 4 and Zero. The card share the I2C bus using only two of the Raspberry Pi’s GPIO pins to manage all eight cards.  This feature leaves the remaining 24 GPIOs available for the user.

POWER REQUIREMENTS

The Raspberry Pi Watchdog needs 5V to operate. For your convenience, the board is equipped with three power connectors: a micro-USB connector similar with the one found on the Raspberry Pi boards, a USB Type-C, and a 2.1mm barrel connector found on many standard 5V power supplies. In order to operate, the watchdog must provide the power to Raspberry Pi.

BATTERY OPERATION

The 18650 Li-Ion battery (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 to the battery due to over-discharging, the processor will cut off the power to Raspberry Pi when the battery drops below 2.8V. A software command is available to the user to also monitor the battery voltage. It is strongly recommended that Raspberry Pi performs a self-shutdown then the battery voltage drops to 3.0V.

SELF TEST

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

DOWNLOADS

Open Source Hardware Schematic

2D CAD drawing

SOFTWARE

SOFTWARE INTERFACES

You can write your own application using the Command Line or Python Libraries provided. Python application example is provided.

 

YOUR KIT

1. SUPER-WATCHDOG add-on HAT for Raspberry Pi

Super-watchdog with battery backup for Raspberry Pi

2. Mounting hardware

Watchdog Mounting hardware

QUICK START

  1. Plug your SUPER-WATCHDOG 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 wdt software from github.com:
  • ~$ 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.