Disabling emonhub, releasing serial port

danbates · 5 October 2019 23:25

Hia, looks like really great work.
A note here, I’ve been having to stop emonhub to free up the UART on the pi for other things, including oem dev. But there’s a problem.
The issue has been that after entering these bash commands:

sudo systemctl stop emonhub
sudo systemctl disable emonhub
sudo reboot

Upon reboot emonhub is back! I don’t know why. There must be some kind of script running on boot which installs the service file and enables it.

Greebo · 6 October 2019 06:44

I think this has been discussed before but couldn’t quickly find the reference (pretty sure it was @borpin that mentioned it previously though?)

Use

sudo systemctl mask emonhub

Check the man page for the differences between disable and mask:
https://manpages.debian.org/jessie/systemd/systemctl.1.en.html

Also note unmask is required instead of enable

borpin · 6 October 2019 16:06

What version of Raspbian/EmonCMS are you running? It is probably the .rclocal that is triggering it.

Yes mask prevents a unit from running until it is unmasked.

danbates · 6 October 2019 20:04

Thanks guys.
I was using Oct18 image with updates.

borpin · 7 October 2019 05:49

So this image will (probably) pick up this rc.local

github.com

openenergymonitor/emonpi/blob/master/stretch/rc.local

#!/bin/sh
#
# rc.local

# rc.local for Raspbian Stretch
echo" My IP address is":
hostname -I

# Create log dirs and files on tempfs partition
# Will only run if /var/log is mounted in tmpfs
if ( mount | grep "on /var/log "| grep -q "^tmpfs " )
then
  for i in "redis" "apache2" "mysql" "openhab" "openhab2" "logrotate" "mosquitto" "supervisor" "emonhub" "emoncms"; do mkdir /var/log/"$i"; done
  for i in "emoncms.log" "mysql.log" "mqtt_input.log" "redis/redis-server.log" "service-runner.log" "mysql/error.log" "apache2/error.log" "supervisor/supervisord.log" "ntp_update.log"; do touch /var/log/"$i"; done
  for i in "emoncms.log" "mysql.log" "mqtt_input.log" "redis/redis-server.log" "service-runner.log" "mysql/error.log" "apache2/error.log" "supervisor/supervisord.log" "ntp_update.log"; do ""chmod 666"" /var/log/"$i"; done
  chown -R root:adm /var/log/apache2
  chown -R redis:redis /var/log/redis
  chown -R mysql:adm /var/log/mysql
  chown -R openhab:openhab /var/log/openhab
  chown -R openhab:openhab /var/log/openhab2

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TrystanLea · 7 October 2019 10:00

Another option could be to disable the RFM2Pi interfacer here:

github.com

openenergymonitor/emonhub/blob/emon-pi/conf/emonhub.conf#L28

    
      
          loglevel = DEBUG #(default:WARNING)
          ### Uncomment this to also send to syslog
          # use_syslog = yes
          
          
#######################################################################
          #######################       Interfacers       #######################
          #######################################################################
          
          
[interfacers]
          ### This interfacer manages the RFM12Pi/RFM69Pi/emonPi module
          [[RFM2Pi]]
              Type = EmonHubJeeInterfacer
              [[[init_settings]]]
                  com_port = /dev/ttyAMA0
                  com_baud = 38400                      # 9600 for old RFM12Pi modules
              [[[runtimesettings]]]
                  pubchannels = ToEmonCMS,
                  subchannels = ToRFM12,
          
          
        group = 210
                  frequency = 433

danbates · 7 October 2019 16:46

I tried disabling the interfacer.
Perhaps there’s a deeper issue with Raspbian. It seems like any activity on the Serial line while the rPi was booting was slowing down the boot process significantly. At the moment, I can only think that emonhub is trying to parse the equivalent of noise. There might be another process before emonhub trying to do something with incoming signals.

borpin · 7 October 2019 17:52

Are you saying a boot with emonhub masked is quicker than with it enabled?

Might be worth experimenting and adding a delay into the service file to delay startup. To do that you need to enable the timer file instead of a service file and edit rc.local so it does not kick it off early. There used to be a delay in rc.local IIRC.

An ‘enabled’ service is just one that starts at boot. If it is installed (and not masked), it can still be started at anytime.