Omzlo PiWatcher 라즈베리용 프로그래밍 가능 와치독 타이머 모듈
(PIWATCHER: The Best Watchdog For Your Raspberry Pi)
개요
- 본 제품은 PiWatcher 라즈베리 파이용 프로그래밍 가능 와치독 타이머 모듈입니다.
- 라즈베리 파이가 멈추어서는 오류가 나거나 전원 절약을 목적으로 라즈베리 파이를 재부팅하거나 완전히 셧다운 시킬수 있습니다.
- 프로그래밍 가능한 와치독 타이머 모듈로 라즈베리 제로부터 라즈베리 파이 4까지 사용이 가능합니다.
- 모듈의 6핀은 라즈베리 파이의 GPIO 헤더에 꼽고, micro USB에 라즈베리 파이 전원을 연결하여 사용합니다.
- 제품은 두가지 형태로 동작합니다.
- 정해진 시간(초) 이내에 응답이 없을 경우 전원 off 혹은 재부팅
- 무한 루프성 태스크 발생후 수초, 수분, 수시간 후에 전원 off 혹은 재부팅
- 보드에는 매뉴얼 제어를 위한 버튼 스위치가 있습니다.
특징
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A solution for Raspberry Pi power management
The PiWatcher is designed to solve 2 problems with power management on the Raspberry Pi.
First, if you shut down a Raspberry Pi through software, for example by issuing a shutdown or halt command, your Raspberry Pi will cease to operate, but it does not completely shut down. Instead, it enters a quiescent state where it continues to eat 30 to 50mA, sometimes more depending on connected peripherals. This is wasteful and can become an issue in battery powered systems.
The PiWatcher can be programmed to fully cut power to the Raspberry Pi after a certain delay of inactivity. For example, you can tell the PiWatcher to cut power 10 seconds after a shutdown command has been issued, giving the Raspberry Pi enough time to cleanly power off.
The second issue with power management has to do with the ability to recover from situations where a Raspberry Pi becomes stuck in an unrecoverable state. While in theory, this should not happen, a long-running Raspberry Pi can get 'stuck' or 'freeze', due to software or hardware failures or even environmental factors such as heat. In some cases the least unsatisfactory approach to deal with this issue is to simply switch off and on again the Raspberry Pi, enabling the application to continue and/or send out an alert.
The PiWatcher can be programmed to automatically power cycle a Raspberry Pi if it does not receive a 'heartbeat' from the device after a user selectable delay. This can allow some critical applications to continue to operate without human intervention.
Furthermore, the PiWatcher can be programmed to wait for a certain delay, ranging from a few seconds to about 36 hours, before rebooting your Raspberry Pi after a shutdown. The PiWatcher has an LED. When the Raspberry Pi is powered on, the LED is continuously on. When the Raspberry Pi is powered off, the LED blinks slowly.
The PiWatcher also has a useful micro tact-switch:
- When your Raspberry Pi is running:
- a long press (5 seconds) on the button will fully power off the Raspberry Pi.
- a short press (half a second) on the button will send a software signal that can be exploited for user-defined purposes.
- When your Raspberry Pi is shut down, a short press on the button will restart the Raspberry Pi.
- The PiWatcher will work with currents of up to 2A, which covers all but the most extreme uses of a Raspberry Pi.
문서
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How to use the PiWatcher
The PiWatcher is fully controlled with a command-line utility called piwatcher, which is very simple to use.
For more details, including software download instructions, see our documentation here.