Super Watchdog for Raspberry Pi

Description

The Super Watchdog is a hardware watchdog and battery backup (optional – no battery included) for all Raspberry Pi boards.

Note: This board is designed for un-protected 18650 cells (due to size). The watchdog provides under-voltage and over-charging protection. Current models feature a full-size capacitor on the underside of the board.

It provides the safety required by mission-critical projects, implementing the following functions:

Power Cycling

It power-cycles the Raspberry Pi in case of software lock-up, resetting not only the Raspberry Pi but also any peripheral attached to it, and prevents SD-card failure in case of power loss by allowing the Raspberry Pi to shut itself down safely.

Self-Check Monitoring

The watchdog has on-board hardware to self check all 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 if the Raspberry Pi is powered down for a specific time interval.
The card has a default timeout of 120 seconds. Once installed, if it does not receive a reset from the Raspberry Pi within 2 minutes, it cuts the power and restores it after 10 seconds.
The 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).
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.

Backup Battery Power (battery not included)

A 18650 Li-Ion battery (not included) 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 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 when the battery voltage drops to 3.0V.

Feature Summary

A must for all RPI mission critical installation
Cycle power after software lock-up
Prevent SD Card damage during power outages
Run for hours on a Li-Ion 18650 battery (not included)
On-board battery charger, step-up converter and intelligent power monitor
Dual power supply jacks: micro-USB and barrel jack
Switch up to 3.5A/5V power to the Raspberry Pi
On-board resettable fuse
Command line or Python configurable

User Guide

Available to download here.

Software

Available on GitHub: https://github.com/SequentMicrosystems/wdt-rpi

Price: £ 25