emonPi LCD V3.0 Update: SSH toggle, Shutdown, Config & CPU reduction

glyn.hudson · 2018-12-11T16:37:30.411Z

Following on from the emonPi SSH disabled by default thread, thanks a lot for everyone who contributed.

For the emonSD release emonSD-30Oct18 (based on Stretch) SSH will be disabled by default for increased security. SSH can be enabled by either: The standard Raspbian way: adding a txt file in /boot called ssh I see this being the preferred method of emonBase users where the SD card is easily accessible. A USB keyboard and HDMI monitor can also be used to create the file if no SD card reader is available. Press and hold the emonPi LCD button for 5s This would be the preferred method for em…

With significant contribution from @alandpearson we have now implemented an update (V3.0.1) to the emonPi LCD service. The update will make it easy to toggle SSH (enable/disable) as required on all emonPi’s. The main features of the update are:

Add toggle SSH features to the LCD
Add shutdown feature to the LCD (shutdown button still works the same)
Add config file for customizing the LCD service e.g. enable custom MQTT data to be displayed
Refactor Redis polling: reduce Pi CPU usage 30%-40%

Here is a video overview of the new update in action:

The update has been merged into master branch and is available to all emonPi users via emonPi update.

This update will be very useful for existing emonPi users to easily disable SSH if it’s not required.

Advance users can now easily customize features such as backlight timeout, default screen and display custom MQTT feed data. Here is the default LCD config file :

[general]
uselogfile = True

# LCD backlight timeout in seconds 0: always on, 300: off after 5 min
# as the emonpi could be installed in a dark place, keep the backlight on, eh ?
backlight_timeout = 0

#How often the LCD is updated when a button is not pressed
lcd_update_sec = 30 

# which page to show after startup (3 is pv/utility readings which should be useful)
default_page = 0
 
#Names for the power feeds displayed on the LCD
feed1_name = Power1
feed2_name = Power2
feed1_unit = W
feed2_unit = W

[mqtt]
mqtt_user = emonpi
mqtt_passwd = emonpimqtt2016
mqtt_host = 127.0.0.1
mqtt_port = 1883
mqtt_emonpi_topic = emonhub/rx/5/values
mqtt_feed1_topic = emon/emonpi/power1
mqtt_feed2_topic = emon/emonpi/power2


[redis]
redis_host = localhost
redis_port = 6379

[huawei]
hilink_device_ip = 192.168.1.1

To view the emonPiLCD script version see the log file:

$ cat /var/log/emonpilcd/emonpilcd.log

e.g

2018-12-12 14:34:57,532 INFO Starting emonPiLCD V3.0.1
2018-12-12 14:34:57,618 INFO I2C LCD DETECTED 0x27
2018-12-12 14:34:58,062 INFO SD card image build version: emonSD-30Oct18
2018-12-12 14:34:58,063 INFO Attaching push button interrupt...
2018-12-12 14:34:58,076 INFO Attaching shutdown button interrupt...
2018-12-12 14:34:58,084 INFO Connecting to redis server...
2018-12-12 14:34:58,088 INFO Connected to redis
2018-12-12 14:34:58,089 INFO Connecting to MQTT Server: 127.0.0.1 on port: 1883 with user: emonpi
2018-12-12 14:34:58,094 INFO Connected to MQTT
2018-12-12 14:35:34,203 INFO Mode button SHORT press
2018-12-12 14:35:34,204 INFO Page: 0

Big thanks to @alandpearson for this update
Here is the original PR:

github.com/openenergymonitor/emonpi

Reduce PI CPU usage by approx 40%, configuration file for emonPiLCD.py & power readings displayed on lcd user configurable

openenergymonitor:master ← alandpearson:master

opened 02:22AM - 27 Nov 18 UTC

alandpearson

+343 -202

Added config file & parser to emonPiLCD.py Allows user to tweak config and ch…oose other values for display for the power readings (for example, if an external power meter is being used) Fixed issue with backlight=0 , and default page is now the power readings, with backlight on. Useful if emonpi is in a dark cupboard (as they usually are) Of course, with a config file the user can easily choose their preferred settings and sane defaults can be added.

Paul · 2018-12-11T23:49:46.083Z

Great to see this finally added, it’s logical to both enable + disable SSH from the interface.

Paul

Steve · 2018-12-12T11:49:24.918Z

I tried to use the backlight_timeout feature (the emonpi is in my kitchen so I don’t want it on all the time) but it has clearly not been tested with non-zero values.

File "./emonPiLCD.py", line 543, in main
    if (backlight_timeout) and now - buttonPress_time > backlight_timeout and lcd.backlight:
NameError: global name 'now' is not defined

Got it working by adding a global declaration of “now”.

glyn.hudson · 2018-12-12T14:39:49.916Z

Thanks, good spot. This must have got missed out during the refactor

I had to add now = now.time() to setup the backlight timer:

github.com

openenergymonitor/emonpi/blob/ea1f98b95de5d12b5836b8ef78b7e7e035078a70/lcd/emonPiLCD.py#L543

    
      
          
          
    if not backlight_timeout: 
                lcd.backlight = 1
          
          
    page = default_page
          
          
    # Enter main loop
              while True:
          
          
        # turn backight off after backlight_timeout seconds
                  now = time.time()
                  if (backlight_timeout) and now - buttonPress_time > backlight_timeout and lcd.backlight:
                      lcd.backlight = 0
                  
                  #Update LCD in case it is left at a screen where values can change (e.g uptime etc)
                  updateLCD() ;
                  time.sleep(lcd_update_sec) 
          
          
if __name__ == '__main__':
              main()

Change has been committed to master (V3.0.1)

github.com/openenergymonitor/emonpi

fix non-zero LCD timeout

committed 02:36PM - 12 Dec 18 UTC

glynhudson

+2 -1

alandpearson · 2018-12-20T00:38:14.929Z

Really glad to see this in the wild.
Good spot on the timeout issue on the display.

I’ll keep an eye here for any further issues that may arise.

Thanks Glyn for the cool video showing it in action.

borpin · 2019-02-20T17:37:06.524Z

2 posts were split to a new topic: Force the Emonpi to AP-mode

pb66 · 2019-03-07T20:50:27.032Z

6 posts were split to a new topic: Problems with GPIO push button on self build emonPi