Updating System Time via Energy Meter with OpenHAB

General
1

Hey everyone, I’m working on a project where I want to synchronize my OpenHAB server’s system time with an energy meter that reports accurate timestamps. Here’s what I’ve been up to and where I could use some guidance:

The Setup

I’m running OpenHAB 2.5.0~S1549-1 on a Raspberry Pi with openHABian. The energy meter communicates via MQTT using an ESP8266 microcontroller. Every hour, the meter sends a timestamp string in the format yyyy-mm-dd hh:mm:ss. My goal is to use this timestamp to update the system time on my OpenHAB server.

The Rule

Here’s the rule I’ve written to handle this:
rule
rule “Update clock from meter”
when
Item PW_hourStamp changed
then
logInfo(“Clock updated to:”, “” + PW_hourStamp.state)
var String hourStamp = “'” + PW_hourStamp.state +“'”
val String results = executeCommandLine("sudo date --set " + hourStamp)
logInfo(“Error from update is”, “” + results)
end

The Issue

When I test this rule, it doesn’t seem to update the system time. Here’s what the logs show:

2020-01-01 13:48:38.308 [INFO ] [thome.model.script.Clock updated to:] - 2020-01-01 13:00:10
2020-01-01 13:48:38.377 [INFO ] [lipse.smarthome.io.net.exec.ExecUtil] - executed commandLine ‘sudo date --set ‘2020-01-01 13:00:10’’
2020-01-01 13:48:39.683 [INFO ] [me.model.script.Error from update is] - null

Interestingly, omitting sudo results in no error messages, but the system time still doesn’t update:

2020-01-01 13:52:02.531 [INFO ] [thome.model.script.Clock updated to:] - 2020-01-01 13:00:10
2020-01-01 13:52:02.542 [INFO ] [lipse.smarthome.io.net.exec.ExecUtil] - executed commandLine ‘date --set ‘2020-01-01 13:00:10’’
2020-01-01 13:52:02.544 [INFO ] [me.model.script.Error from update is] - null

What I’ve Tried

  • Permissions: I’ve checked that the sudo command is working correctly and that the OpenHAB user has the necessary permissions.
  • Command Variations: I’ve tried different variations of the date command, including specifying the timezone.
  • Logging: I’ve added extensive logging to track the command’s execution and output.

Questions

  1. Is there a better way to update the system time from a rule in OpenHAB?
  2. Could there be an issue with how sudo is handling the command in this context?
  3. Are there any alternative commands or methods that might work more reliably?

Next Steps

I’m considering the following approaches:

  1. Using hwclock instead of date to set the hardware clock.
  2. Checking if the chrony service is running and properly configured.
  3. Adjusting the sudoers file to grant specific permissions for the date command.

Any advice or suggestions would be greatly appreciated! Thanks in advance for your help.

Best regards,
Per