Seed bins and seed trays - protection from rain

Hardware
1

does anybody has a solution to protect the seed bins resp. seed trays against getting wet (e.g. rain)?

I assume the design does not implicate to fill the tray just instantly before replanting single plants but should allow to run farrmbot autonomously for at least some days.

How could a rain cover look like allowing the vertical access of the seeder? Maybe the seeder pushes the cover away with a horizontal movement before picking up the the seed and a spring pushes the cover back afterwards.

P.S.: another more crazy idea would be to replace the vacuum pump by using the gravity for seeding. The alternative seeding tool has an small internal reservoir and by means of an electronic impuls it would let out seed by seed.
A self-printed refill station could refill the local reservoir also by means of gravity. Something like this just smaller and it opens by pushing instead of turning http://www.dieedelstahlprofis.com/muesli-suessigkeiten-kaffeebohnenspender-wandmontage/a-572/

2

I’ve thought about a spring loaded or servo actuated plastic cover before, though we haven’t made any prototypes. Right now the idea is that seeds would be loaded by the owner whenever needed. Say once every week or two, or just a few times per season. Once FarmBot finished planting them, any extras would be put away so as to not be ruined by the sun, rain, or eaten by birds.