How to get a the previous outTemp value in a driver

[peterq...@gmail.com]

I have a customized Acurite driver where I've replaced the temperature reading with a reading from a different sensor. My sensor is placed so that I occasionally get temperature spikes in the late afternoon when the sun hits it. I've tried to shield it without complete success. I'm looking for a software solution where I can remove the bad values for the 10 minutes a day where it can jump up 5 degrees.

I think I know how to do this, but I'm stuck on getting the previous temperature value in the driver. Is there an easy way to do this? 

The docs suggest  weewx.manager.open_manager_with_config with the appropriate SQL query is the way to go. Is it?

[Tom Keffer]

The problem with using open_manager_with_config is that you have to make assumptions about which database binding is being used.

Off the top of my head, here are 3 alternative solutions:

1. You could cache the previous value.

2. You could fix the problem downstream by using a weewx service.

3. You could use multiple inheritance, so your driver inherits both from weewx.drivers.AbstractDevice and from weewx.engine.StdService. Getting a database manager is then easy:

dbmanager = self.engine.db_binder.get_manager(self.data_binding)

See the Vantage driver for an example of using multiple inheritance (although it does not access the database).

But, really, you should relocate the sensor!

-tk

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[peterq...@gmail.com]

Thanks!

Now that you mention it, it would be super easy to cache the old value. But, I took your advice and moved the sensor.