Safely Shutting down Base unit when powered?

janoska666 · 14 June 2017 06:52

Hi folks. I have set up a Base unit and a Emon Tx . All works fine thanks to your help.

How do shut down the base unit correctly before removing power. I dont want to cook the SD card.

The PI unit has a shutdown button apparently. Maybe the Base unit needs a little remote shutdown button.

Regards and thanks

Bill.Thomson · 14 June 2017 10:48

If you have a keyboard and monitor connected to your emonBase,
execute the command sudo poweroff

If you don’t have a keyboard and monitor connected,
execute the command ssh pi@ip_address sudo poweroff

you’ll be prompted for the emonBase password. After you enter the password, the command will run.
You may get an error message about a broken pipe, but it can be ignored.

Note: ip_address> is the emonBase IP address.

glyn.hudson · 14 June 2017 13:28

The hostname can also be used to connect via SSH:

ssh pi@emonpi

the default SSH password: is emonpi2016

Bill.Thomson · 19 June 2017 12:59

Keep in mind that method works only if the emonpi IP address is included in the hosts file of the machine that’s running the SSH client.

glyn.hudson · 22 June 2017 13:13

emonpi.local suffix is required on some networks e.g.

ssh [email protected]

http://emonpi.local works on my office network while http://emonpi works on my home network

Bill.Thomson · 22 June 2017 13:34

For that to work, Avahi needs to be running on a Linux client, or Bonjour on a Windows client.

janoska666 · 22 June 2017 13:49

Hi folks all taken onboard. On a diffrent note i have a PI based energy monitor from America, Its quite smart.
It uses a small remote shutdown button connected to the I/O ports and runs a python script to shut it down safely.It makes it foolproof.
I may open another post on this unit later. I used for offgrid generator monitoring . Here is the basic outline and link Useful Bits and Bytes: Multichannel Professional Data Logger on Raspberry Pi - Part 2

Multichannel Professional Data Logger on Raspberry Pi - Part 2
Software tools, applications and frameworks I found interesting or useful. Mostly around Java, Maven, Teiid, wit…

John o shea

glyn.hudson · 22 June 2017 15:17

emonpi.local works on the standard emonSD image on Ubuntu Linux with Chrome / Firefox and also tested to work on Android Chrome. No extra services required. I imagine Avahi is running as standard on Ubuntu and Android. Tested on Ubuntu 16.04 and Android 7.

Yup, nice solution. We do the same on the emonPi, use a button to trigger shutdown via GPIO pin. The emonPi shuts down if GPIO 11 is low for 5s then the emonBase will shutdown:

github.com

openenergymonitor/emonpi/blob/master/lcd/emonPiLCD.py#L97


      
          #!/usr/bin/env python
          import sys
          import smbus
          
          # Find LCD (alternative to i2cdetect)
          bus = smbus.SMBus(1)
          for address in ['0x27','0x3f','0x3c']:
              try:
                  bus.read_byte(int(address,16))
                  break
              except Exception:
                  address=False
          
          if address=='0x27' or address=='0x3f':
              import emonPiLCD1
              emonPiLCD1.main()
              
          elif address=='0x3c':
              import emonPiLCD2
              emonPiLCD2.main()
          
          else:
              print("Device address not recognised")

On the emonBase since no LCD is detected this python scripts exits, you can override this by commenting out this check:

github.com

openenergymonitor/emonpi/blob/master/lcd/emonPiLCD.py#L124


      
          #!/usr/bin/env python
          import sys
          import smbus
          
          # Find LCD (alternative to i2cdetect)
          bus = smbus.SMBus(1)
          for address in ['0x27','0x3f','0x3c']:
              try:
                  bus.read_byte(int(address,16))
                  break
              except Exception:
                  address=False
          
          if address=='0x27' or address=='0x3f':
              import emonPiLCD1
              emonPiLCD1.main()
              
          elif address=='0x3c':
              import emonPiLCD2
              emonPiLCD2.main()
          
          else:
              print("Device address not recognised")

Bill.Thomson · 22 June 2017 21:21

And that’s a good thing.

But… If the box you’re issuing the command from isn’t running Ubuntu or isn’t running avahi, it doesn’t work.

If the box issuing the commend is running Windows, (unless it’s running Bonjour or an equivalent) it won’t work there either.

I just tried shutting down a Pi (running the latest emonSD image) from a machine running Debian (no avahi) and received this error message: Could not resolve hostname emonpi.local: Name or service not known

No joy with PuTTY on Windows 7 either. Even though Windows isn’t the world’s most liked OS, there are too many Windows boxes in use to just turn a blind eye to them.

Robert.Wall · 22 June 2017 22:08

That’s exactly why the now-deprecated calibration instructions that I wrote were done with Winten running in a VM as well as on my native Ubuntu.

richy1995 · 10 January 2020 19:15

In the Admin menu, there is now a shutdown button, as well as reboot.

pfischer · 24 November 2023 13:21

Indeed as at 2023-11 there are 1.4 billion windows pcs running