As the convener for the Adelaide community of The Things Network, I am frequently setting up Multitech Conduit Gateways. Depending on your PC or notebook hardware you might have some problems with the Exar USB-UART driver on Linux.

Here are the steps to getting this unit setup from an Ubuntu (should work for any other Linux distro) machine.

lsusb

Should show something like this:

Bus 002 Device 006: ID 04e2:1410 Exar Corp. XR21V1410 USB-UART IC

Installing VirtualBox is getting increasingly painful on Ubuntu due to the problems with UEFI Secure Boot and the VirtualBox kernel modules. Another reason for an alternative is that running VirtualBox VM’s completely in the background is not as straightforward as it could be.

From the available alternatives I looked into (VMWare, Xen & KVM) it was KVM that fitted my needs (casual VM usage with mostly headless VM’s for testing purposes). Main reasons:

Install XScreenSaver and remove Gnome default

sudo apt remove gnome-screensaver
sudo apt install xscreensaver xscreensaver-gl xscreensaver-gl-extra

Run the Screensaver UI and configure

In the “Advanced” section enter your Flickr RSS URL in “Choose Random Image”

https://api.flickr.com/services/feeds/photos_faves.gne?id=YOURFLICKRUSERID #replace with your Flickr User ID

Create a systemd user service to autostart

mkdir -p ~/.config/systemd/user/
vim ~/.config/systemd/user/xscreensaver.service

[Unit]
Description=XScreenSaver
[Service]
ExecStart=/usr/bin/xscreensaver -nosplash
[Install]
WantedBy=default.target

Start and enable systemd user service

systemctl --user enable xscreensaver
systemctl --user start xscreensaver

To copy the settings (including RSS URL) onto other PC’s or re-install it might be a good idea to backup or copy the contents of ~/.xscreensaver

One of the things that is not implemented in the Secure Shell Chrome extension is the ability to remove know_host fingerprints which alert you if the fingerprint for a specific IP address has changed.

However there are times when you upgrade a systems and this need to be done.

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
d6:be:12:7e:22:23:c3:e1:56:30:d6:cd:65:b7:ab:42.
Please contact your system administrator.
Add correct host key in /.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /.ssh/known_hosts:7
ECDSA host key for xxxxxxxxxxxxx.yyy.au has changed and you have requested strict checking.
Host key verification failed.
NaCl plugin exited with status code 255.
(R)econnect, (C)hoose another connection, or E(x)it?

On remote systems sometimes a web-based tool can be very handy. Webmin is such a tool that has been well maintained for decades. To install quickly on a Ubuntu Server without having to manage dependencies and keeping it updated as part of normal OS update operations installing from a PPA Repo is handy.

sudo echo "deb http://download.webmin.com/download/repository sarge contrib" >> /etc/apt/sources.list

wget -q http://www.webmin.com/jcameron-key.asc -O- | sudo apt-key add - sudo apt-get update sudo apt-get install webmin`

Just a quick note on install and configuration of Conky.

Installation

sudo apt-get install conky conky-all hddtemp curl lm-sensors
sudo chmod u+s /usr/sbin/hddtemp
sudo sensors-detect

vim ~/.conkyrc

This is the content of my config file.

use_xft yes
xftfont Ubuntu Condensed:size=9
xftalpha 0.8
override_utf8_locale yes
update_interval 5.0
total_run_times 0
own_window yes
own_window_transparent no
own_window_argb_visual yes
own_window_argb_value 155
own_window_colour 081100
own_window_type normal
own_window_class conky-lgaggl
own_window_hints undecorated,below,sticky,skip_taskbar,skip_pager
#background yes
#out_to_console no
double_buffer yes
#max_user_text 32768
minimum_size 300
draw_shades no
draw_outline no
draw_borders no
draw_graph_borders yes
default_shade_color black
default_outline_color white
default_bar_size 150 5
default_gauge_size 20 20
imlib_cache_size 0
draw_shades no
alignment middle_right
gap_x 15
gap_y 15
border_inner_margin 10
no_buffers yes
uppercase no
cpu_avg_samples 2
override_utf8_locale no
default_color ffffff
color1 ffffff
color2 cccccc
color3 000000
color4 FFAA00

TEXT
${font UbuntuBold:bold:size=11}${color4}Info ${color2}${hr 2}${font}
${color1}Date ${alignr}${color2}${time %a,}${color}${time %e %B %G}
${color1}Time ${alignr}${color}${time %T}

${font UbuntuBold:bold:size=11}${color4}System ${color2}${hr 2}${font}
${color1}Hostname ${alignr}${color}${nodename}
${color1}${sysname} ${alignr}${color}${kernel}-${machine}
${color1}CPU ${alignr}${color}${freq_g}GHz
${color1}Loadaverage ${alignr}${color}${loadavg 1} ${loadavg 2} ${loadavg 3}
${color1}Uptime ${alignr}${color}${uptime}
${color1}Cpu Temperature ${alignr}${color}${acpitemp}C

${font UbuntuBold:bold:size=11}${color4}Processors ${color2}${hr 2}${font}
${color1}Core 1 ${alignr}${color}${cpu cpu1}% ${cpubar cpu1}
${color1}Core 2 ${alignr}${color}${cpu cpu2}% ${cpubar cpu2}
${color1}Core 3 ${alignr}${color}${cpu cpu3}% ${cpubar cpu3}
${color1}Core 4 ${alignr}${color}${cpu cpu4}% ${cpubar cpu4}

${font UbuntuBold:bold:size=11}${color4}Memory ${color2}${hr 2}${font}  
${color1}Memory ${color}${alignr}${memeasyfree} / ${memmax}  
${color1}Currently ${color}${alignr}${memperc}% ${membar}

${font UbuntuBold:bold:size=11}${color4}Filesystem ${color2}${hr 2}${font}  
${color1}/ ${color}${alignc}${fs_used /} / ${fs_size /} ${color}${alignr}${fs_free_perc /} %  
${color}${fs_bar 5,300 /}

${font UbuntuBold:bold:size=11}${color4}Networking ${color2}${hr 2}${font}  
${if_existing /proc/net/route wlan0}${color1}Ip ${color}${alignr}${addr wlan0}  
${color1}AP ${color}${alignr}${wireless_essid wlan0}  
${color1}Signal ${color}${alignr}${wireless_link_qual_perc wlan0}${wireless_link_bar 10,100 wlan0}  
${color1}Download ${alignr}${color}${downspeed wlan0}${downspeedgraph wlan0 10,100}  
${color1}Upload ${alignr}${color}${upspeed wlan0}${upspeedgraph wlan0 10,100}  
${color1}Total Down/Up ${alignr}${color}${totaldown wlan0}${color1}/${color}${totalup wlan0}  
${else}${if_existing /proc/net/route eth0}${color1}Ip ${color}${alignr}${addr eth0}  
${color1}Download ${alignr}${color}${downspeed eth0}${downspeedgraph eth0 10,100}  
${color1}Upload ${alignr}${color}${upspeed eth0}${upspeedgraph eth0 10,100}  
${color1}Total Down/Up ${alignr}${color}${totaldown eth0}${color1}/${color}${totalup eth0}${endif}${endif}

${font UbuntuBold:bold:size=11}${color4}Weather ${color2}${hr 2}${font}
${color1}Temperature ${alignr}${color}${weather https://tgftp.nws.noaa.gov/data/observations/metar/stations/ YPAD temperature} C
${color1}Humidity ${alignr}${color}${weather https://tgftp.nws.noaa.gov/data/observations/metar/stations/ YPAD humidity} %
${color1}Weather ${alignr}${color}${weather https://tgftp.nws.noaa.gov/data/observations/metar/stations/ YPAD weather}

${font UbuntuBold:bold:size=11}${color4}Top Processes ${color2}${hr 2}${font}
${color1}${top name 1} 	${alignr}${color}${top cpu 1} ${top mem 1}
${color1}${top name 2} 	${alignr}${color}${top cpu 2} ${top mem 2}
${color1}${top name 3} 	${alignr}${color}${top cpu 3} ${top mem 3}
${color1}${top name 4} 	${alignr}${color}${top cpu 4} ${top mem 4}
${color1}${top name 5} 	${alignr}${color}${top cpu 5} ${top mem 5}

Note: if you want to use this config file you want to at least change the METAR code (YPAD in my case) with one closer to you – see http://www.rap.ucar.edu/weather/surface/stations.txt.

Turns out that the Broadcom BCM2708 chip on the RPi has a hardware watchdog. This can be very useful if your RPi is located remotely and locks up. However, this would not the preferred method of restarting the unit and in extreme cases this can result in file-system damage that could prevent the RPi from booting. If this occurs regularly you better find the root cause of the problem rather than fight the symptoms.