Raspberry pi camera servers

This is notes from installation multi-raspberry pi camera (3 or 5 raspberry pi, each with a camera). The camera images is then collected in one single camera server.

This configuration guide is for the raspberry pi cameras and for the single camera server.

Prerequisites

It is assumed that mobotware is compiled for (or on) raspberry, and installed to /usr/local/smr, e.g. from the mobotware directory like this:

cd mobotware
make
sudo make install

Make takes a long time (one hour or so).

The make install installs the needed files into /usr/local/smr.local and links to this from /usr/local/smr. But do not put anything into /etc/rc.local.

Files needed

In mobotware a configuration example is in mobotware/build/config/gogo and mobotware/build/config/gogo/picam.

ls mobotware/build/config/gogo
  picam  rhdconfig.xml  ucamserver.ini
ls mobotware/build/config/gogo/picam
  aukeeper.ini  connectrhd.rule  keepcam.rule  keeplaser.rule  keepnav.rule  rc.local  startKeeper  ucamserver.ini

In mobotware/build/config/gogo/picam is the configuration files for the raspberry pi camera, the mobotware/build/config/gogo/ucamserver.ini is the configuration file for the single image collecting camera server (mostly for image recording).

Raspberry pi camera

The raspberry pi cameras in this example is named rpi6, rpi7, ... rpi10 as their hostname (in /etc/hostname).

Keeper

The keeper is a server that starts the cameraserver when needed (and restarts it if it crashes or gets stuck in other ways).

The Keeper should be started at reboot using the /etc/rc.local, like this line almostat the end of rc.local:

# rc.local
...
# start keeper
su -c "/home/local/startKeeper" local
#
exit 0

This starts a script placed in /home/local named startKeeper as the user local. This is to run as much as possible without root privileges.

Copy the start script to /home/local (beeing the user local:

cd
cp mobotware/build/config/gogo/picam/startKeeper .
chmod +x startKeeper

Make a live directory where the configuration files for keeper and camera server resides, and copy the ini-files:

mkdir live
cd live
cp mobotware/build/config/gogo/picam/*.ini .

Theaukeeper.ini file looks something like this

# open server - port and path
server port=24926
server imagepath="/var/log/keeper"
server datapath="/var/log/keeper"
module load=var
# cam
module load="if" alias=cam
cam connect=localhost:24920
camonconnect cmd="cam push t=3 cmd='var allcopy'"
var global.requiredclients=1
var global.keep.cam=1
var global.caminifile="/home/local/live/ucamserver.ini"
# start rules
module load="aurule.so.0"
rule log=false
rule load="/usr/local/smr/bin/aursconf/keepcam.rule"
rule resume

The keeper uses a rule to monitor and restart the cameraserver, this is assumed to be placed in /usr/local/smr/bin/aursconf, so copy the rules there (they may be there already, so probably not needed)

sudo cp *.rule /usr/local/smr/bin/aursconf/

The rule used for the camera server looks like this:

<?xml version="1.0" ?>
<rule name="keepcam" if="defined('cam.connected')">
 <description>
   * This rule is trying to keep cam server running, when the
   number of clients is more than required in global.requiredclients and
   the variable global.keep.cam is true.
   * This rule starts when the cam interface module is available (and
   has created the variable cam.connected).
   * When number of clients falls below the number of required, then
   the server is closed (if it was started by the keeper).
   * If the cam server is running already then the keeper will monitor the running
   instance and restart it if it crashes. The server is crashed if no "alive" signal
   is received within 3 seconds (value in alive rule below)
 </description>
 <init>
   # define global status variables
   global.alive.cam = false
   global.alive.camStarted = false
   allow = 7  # allow time is allowed time to be dead
   if (not defined('global.keep.cam'))
     global.keep.cam=false
   deadCnt = allow + 1
   <rule name="alive" if="cam.connected[1] and
                         cam.hostalive and
                         not global.alive.cam">
     global.alive.cam = true
     print("cam is alive after " deadCnt " secs to start")
     deadCnt = 0
     allow = 3  # seen alive to dead detect
   </rule>
   <rule name="deadCnt" if="not cam.connected[1] or not cam.hostalive">
     # if (deadCnt < 0.51)
     #   print("cam seems to be dying " deadCnt " : cam.connected=" cam.connected[1] ", cam.alive=" cam.hostalive)
     deadCnt = deadCnt + rulestate.sampletime
   </rule>
   <rule name="noclient" if="cam.connected[1] and
                             global.requiredclients > core.clients and
                             global.alive.camStarted">
     global.alive.camStarted = false
     print("Closing cam server - as there is no clients left on port " core.port)
     core.send("cam quit")
   </rule>
   <rule name="dead" if="deadCnt >= allow and global.alive.cam">
     print("cam assumed dead after " deadCnt " secs with no responce")
     print(" - cam status: cam.connected=" cam.connected[1] ", cam.alive=" cam.hostalive)
     global.alive.cam = false
     global.alive.camStarted = false
   </rule>
   <rule name="start" if="core.clients >= global.requiredclients and
                         not global.alive.cam and
                         not global.alive.camStarted and
                         global.keep.cam">
     <init>
       inistr=" "
       startstr=" "
     </init>
     deadCnt = 0
     if (defined("global.caminifile"))
       inistr = "--script " global.caminifile
     global.alive.camStarted = true
     allow = 30 # allow for start-up time
     # startstr = 'su -c "nice --adjustment=5 /usr/local/smr/bin/startserver ucamserver ' inistr '" local' 
     startstr = 'nice --adjustment=5 /usr/local/smr/bin/startserver ucamserver ' inistr
     core.send("bash " startstr)
   </rule>
 </init>
 # keep monitoring rule active
 wait() : false
</rule>

It is a XML formatted rule script, as defined for the aurule.so.0 plugin.