I have set up a system logging temperatures (and later hopefully also other parameters) to a postgres database. The data are now read out and presented as an svg-graph. (this may not work in some older browsers, i.e. msie< 9 - it is possible to use svgweb, but I have presently not implemented this)
The source code for the system is available at my github account. The version presented here, is at tag passive_plot – in the last version it is possible to read out data, clicking in the chart. Later it will also be shown how to put more charts on one web page.
Why not just use cosm? Well, in fact I am uploading my data to cosm (in fact the intermediate json format used in this project is compatible with cosm), but on one side, I like to have control and know that I know where and in which format my data are, I also do not like the ways it is possible to present data on cosm (e.g. if a long time series is presented,points are thrown away, which may be strongly misleading if a point with a (local) minimum or maxima is removed – that happens quite often)