14-power-management.Rmd

# Power Management

Power management on the Raspberry Pi is useful when deployments are made that are powered by batteries and/or renewable sources such as solar power that are intermittent. 

In addition, there are small environmental benefits on consuming less power on systems which have continual grid power.

The `pi-pwr` script can be used to turn off unused functionality, either always or just when it is not required.

## Installation of power management tools

The power management tools are installed as part of the node installation process, however they can be easily installed independently on any Raspberry Pi system.

````{bash eval=FALSE}
wget -O - https://github.com/wildlife-systems/pi-pwr/raw/master/install | sudo bash
````

## Turning funtionality on and off

## Considerations

Disabling all network functionality will prevent the node from communicating until either the functionality is turned back on or the Raspberry Pi is restarted.

If disabling all connectivity is desired periodically then the functionality to turn these systems back on must be scripted.

### A note on `sudo`

Raspberry Pi OS (and previously Raspbian) allows the default user to run sudo without a password. This is not true for other Linux distributions, such as Ubuntu. This could lead to a password prompt when using `pi-pwr`. As nodes are designed to run autonomously, the installation process for `ws-node` will configure `pi-pwr` to not require a `sudo` password.