4. Administrators Guide¶
This section of the manual deals with configuring Picroscopy either via the command line switches or via a configuration file specified on the command line. It also provides rudimentary guidance on configuration of the Raspbian operating system under the assumption that this is the operating system most users will be using for Picroscopy.
Note
If any users wish to use Picroscopy with Arch Linux (the other
major distro available for the Raspberry Pi platform), please feel free to
submit documentation patches to the author. If you are reading this on
ReadTheDocs, this can be done trivially with the Edit on GitHub
link
on the left of the page.
4.1. Network configuration¶
The /etc/network/interfaces
file holds the network configuration under
Raspbian. The default configuration which is shown below, attempts to obtain
an IP address via DHCP:
iface eth0 inet dhcp
Should you wish your Pi to use a static address you will need to edit this file. A typical static address configuration for the private 10.0.0.0 network is shown below:
iface eth0 inet static
address 10.0.0.150
netmask 255.0.0.0
gateway 10.0.0.1
Another static configuration is shown below, this time for the private 192.168.0.0 network typically used by home routers:
iface eth0 inet static
address 192.168.1.3
netmask 255.255.255.0
gateway 192.168.1.1
After changing /etc/network/interfaces
you will need to restart the
networking service for the changes to take effect (note that if you are
connected to your Pi via SSH this will very likely break your session):
$ sudo service networking restart
Alternatively you can simply reboot:
$ sudo reboot
4.2. Command Line¶
Picroscopy is started from the command line with the picroscopy
command.
Typically, options for the application are either passed as command line
switches, or are specified as entries in a configuration file which is
specified with the picroscopy -c
option. If an option appears both
in the configuration file and as a switch on the command line, the command
line switch will take precedence. Specifically, the order of precedence for
options is:
- command line switch
- configuration key
- default
The Picroscopy application does not fork like a daemon once started. As it is a single user application that utilizes the Raspberry Pi’s display there is little point in running as a system daemon, despite using a web interface. Furthermore, as the system monopolizes the Pi’s display output, it is reasonable to expect that the application will be the only (visible) application running at any given time.
To this end, you may wish to configure the system to start Picroscopy at boot time, and shut down (or reboot) the Pi when the application terminates. A simple method for accomplishing this is to write a bash script similar to the following:
#!/bin/bash
picroscopy -c myconfig.ini
poweroff
Simply change the last line to reboot
if you wish to reboot when picroscopy
exits instead of powering off the computer. Save this script as
/root/run_picroscopy.sh
and make it executable by running the following
command:
chmod +x /root/run_picroscopy.sh
To run this script on startup (without interfering with the rest of the boot
sequence), add the following to the end of /etc/rc.local
:
/root/run_picroscopy.sh &
The ampersand (&) at the end of the line ensures the script is started in the background, permitting the rest of the boot sequence to continue.