i favour the collection of sensors approach as compared to the centralised weather station approach
suppose the weewx driver was just a heartbeat - creates an empty LOOP packet with a timestamp. then all data sources would be a service that insert their data since last heartbeat. but, compared to present ‘dataful driver’, it would lose the coherency of data inside each packet by coherency, i mean that in the present design we expect every LOOP packet to carry a meaningful ‘snapshot’ of the world, to the point where we can even fill in gaps by deriving values from combinations of values present in the packet (e.g. ET). loss of LOOP coherency means it might take several packets to gather enough info to make such a derivation. that derivation would have to be made by a stateful engine monitoring LOOP packets - a bit of an expansion of StdWXCalculate from today off the top of my head, a derivation service could have a set of inputs, each described as (obs_type, last value, expiry time), mapped into a set of outputs, each described as (obs_type, calculation). whenever an output has all non-expired inputs satisfied, it fires and injects a derived value all this presumes that on a regular basis - the archive interval - we have collected enough data to provide a coherent set to present to the world as ‘reports’ as i think about pat’s situation, which is a need to add packets on demand, the heartbeat driver could take requests to fire a packet immediately. or to hurry up or slow down. pushing the analogy perhaps too far, if *everyone* fires packets whenever they want (probably a system config mistake) then do we risk arrhythmia..? > On 16 Feb 2021, at 1:51 am, Tom Keffer <[email protected]> wrote: > > The general problem is that WeeWX allows only one driver, and, for better or > worse, the trend over the last few years has been for people to use more than > one device feeding the WeeWX engine. -- You received this message because you are subscribed to the Google Groups "weewx-development" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-development/1B7B10DB-1696-4689-847D-DBA344613E46%40gmail.com.
