(Note that 4.1.0 (build 4024) - 05 June 2024 remains available, but usage of this version is not recommended - particularly for Davis stations - and the included utility in this distribution for migrating to v4 is known to contain errors affecting conversion of dayfile.txt)
Legacy Cumulus 1 release 1.9.4 (build 1099) - 28 November 2014
(a patch is available for 1.9.4 build 1099 that extends the date range of drop-down menus to 2030)
Download the Software (Cumulus MX / Cumulus 1 and other related items) from the Wiki
From build 3044 the development baton passed to Mark Crossley. Mark has been responsible for all the Builds since. He has made the code available on GitHub. It is Mark's hope that others will join in this development, but at the very least he welcomes your ideas for future developments (see Cumulus MX Development suggestions).
Just so you know that is not a sensor but the heap_free value (a memory value) for the gateway. It will indicate a possible memory leak in future should one happen, the value will continually decrease if such a situation arises.