During the last days I prepared and configured a sd-card with OpenWrt (SNAPSHOT r14740-0b31713c85) for the NanoPi R1. So far: it works. Thanks to all contributors.
Nevertheless there are two points, where I don't know, whether there is a bug or a mistake by me.
In luci-app-statistics I enabled thermal infos (default config, no customization), but there are no pictures (which I had in FriendlyWRT 19.07.1). In /sys and its sub-directories there isn't any file named temp (which was present in FriendlyWRT 19.07.1). Bug or faulty configuration?
Furthermore I noticed: there is no /tmp/rrdimg directory (/tmp/rrd with the data files exists), which contains all diagrams I can see under Statistics->Graphs. But (with the exception of thermal info) I can see all diagrams.
In /etc/config/luci I have the following section:
config internal 'apply' option rollback '30' option holdoff '4' option timeout '5' option display '1.5'
but the timer always starts with 90 seconds. Bug or faulty configuration?