Raspberry Pi Watchdog and Battery Backup for all Raspberry Pi Boards.
New version, optimized for Raspberry Pi 4, now in stock.
The fourth release of the watchdog has been optimized for Raspberry Pi-4. The barrel power connector, which was rated 2A, has been replaced with the 5A version. The step-up power supply, which feeds the Raspberry Pi from battery when the power runs out, has been redesigned to supply minimum 3A required by Rpi-4. We have added an USB-C type connector, so you can use the power supply which comes with Rpi-4, but to keep compatibility with previous generations, we also kept the USB-B connector.
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.
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.
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.
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.
The Raspberry Pi Watchdog needs 5V to operate. For your convenience, the board is equipped with two power connectors: a micro-USB connector similar with the one found on the Raspberry Pi boards, 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.
OPEN SOURCE HARDWARE
WHAT’S IN YOUR KIT
SUPER-WATCHDOG add-on card for Raspberry Pi
QUICK START-UP GUIDE
- Plug your SUPER-WATCHDOG card on top of your Raspberry Pi and power up the system from the watchdog.
- Enable I2C communication on Raspberry Pi using raspi-config.
- 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
The program will respond with a list of available commands.