Raspberry Pi Tips / Issues

Some stuffs…

To check if we are on lite version, (well one way to do it…) is to check if raspberrypi-ui-mods package is installed. The following command will return nothing if it is not installed - so, we are probably on lite then.

$ sudo apt list raspberrypi-ui-mods --installed

I run desktop-less Raspbian (Buster) and somehow the timezone got reset. To set that,

# sudo timedatectl set-timezone Asia/Kuala_Lumpur

Edit /etc/hostname and /etc/hosts - modify accordingly, and reboot immediately.

$ name=my1pi
$ prev=$(cat /etc/hostname)
$ sudo sed -i "s/$prev/$name/" /etc/hostname
$ sudo sed -i "s/$prev/$name/" /etc/hosts
$ sudo reboot

The simplest way is… install xscreensaver and disable it!

# sudo apt install xscreensaver

Script to make Pi an e-Photo Frame.

eframe.sh

#!/bin/bash
 
SHOW_PATH="/home/pi/Pictures"
[ -d "$1" ] && SHOW_PATH=`cd $1;pwd`
SHOW_EXEC="feh"
SHOW_FULL=`which $SHOW_EXEC 2>/dev/null`
# args: delay 5s, fullscreen, recursive, randomize
SHOW_ARGS="-D5 -F -r -z"
 
echo "Accessing pictures in $SHOW_PATH..."
# press esc to quit?
${SHOW_FULL} ${SHOW_ARGS} ${SHOW_PATH}

• get the following info: address, netmask, broadcast, network, gateway
  • to get address, netmask, broadcast:

    $ ifconfig
    eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 10.170.7.195  netmask 255.255.255.0  broadcast 10.170.7.255

  • to get network, gateway:

    $ netstat -nr
    Kernel IP routing table
    Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
    0.0.0.0         10.170.7.1      0.0.0.0         UG        0 0          0 eth0
    10.170.7.0      0.0.0.0         255.255.255.0   U         0 0          0 eth0

• edit /etc/network/interfaces and change

  iface eth0 inet dhcp

  to

  iface eth0 inet static
  address xxx.xxx.xxx.xxx
  netmask xxx.xxx.xxx.xxx
  network xxx.xxx.xxx.xxx
  broadcast xxx.xxx.xxx.xxx
  gateway xxx.xxx.xxx.xxx

  note: fill in the info accordingly

Note Got these from R-Pi site.

The HDMI monitor (or HDMI adapter) may only support a limited set of formats for CEA (TV) or DMT (Monitor). To find out which formats are supported, use the following method:

• Set the output format to VGA 60Hz (hdmi_group=1 and hdmi_mode=1) and boot up your Raspberry Pi
• Enter the following command to give a list of CEA-supported modes: /opt/vc/bin/tvservice -m CEA
• Enter the following command to give a list of DMT-supported modes: /opt/vc/bin/tvservice -m DMT
• Enter the following command to show your current state: /opt/vc/bin/tvservice -s

Then edit config.txt to select:

• hdmi_group={0:EDID_auto_detect,1:CEA,2:DMT}
• hdmi_mode={select from tvservice output}

Note: This assumes a Raspbian installation with desktop environment, and username is pi.

• create path /home/pi/.config/autostart
• create a desktop file in there (e.g. monitor.desktop)

  monitor.desktop

  [Desktop Entry]
  Type=Application
  Name=Monitor
  Exec=/path/to/exec

start_fullscreen.sh

#!/bin/bash
 
chromium-browser http://server.local:1337 --start-fullscreen