Config for my moto harpia to turn it into a bike computer. We will
need

- working gps
- bluetooth (ble) stuff
- wayland "cage" compositor
- an app
- rsync service so that trails can be downloaded to a computer
- ip connectivity with flight mode
 - give it telent and dandroid as APs
 - use rfkill aggressively to save battery
 

Absent any reason I should not write the app in fennel I'm going to
write the app in fennel. I want it to

- display speed/cadence/time of day/power
- show where I am on a map
- record trail of where I've been (note: indoor counts too)



can we somehow do non-flakey bluetooth (is it dbus?)



cool extras
===========

adjust screen brightness 

* turn off backlight when stopped after a minute
* dim the screen when following a route and the next
 navigation instruction is still some way off
* tap to wake screen

note that IPS LCD requires as much battery for dark pixels
as light ones, so we get no power saving by colouring only part
of the screen


------

random notes follow ...

1) Satellite requires these commands to be run before
it will work. 

  mmcli -m 0 --enable
  mmcli -m 0 --location-enable-gps-raw
  mmcli -m 0 --location-enable-gps-nmea 
  mmcli -m 0 --location-status


2) we should make saturn give visual feedback while it's loading an
app. How does it know when the app has finished loading?  Maybe it
could get told when its window is obscured