I forgot to mention that. Condensation is a really important factor as Grumpy_Mike says. So you could put everything in a plastic box that is waterproof.
That's going to pretty much guarantee condensation!
As air cools the amount of moisture it can hold in solution (as vapour) decreases markedly - this then condenses as droplets.
The most straightforward way to prevent condensation is to ventilate and insulate. Ventilate to allow moist air to be replaced
by colder dry air. Insulate to stop the rapid temperature drop as night falls - that is when condensation is most likely as heat radiates
away from objects and they become cooler than the air (not such a problem inside a shed though?)
Alternatively if you place in a sealed container you need to seal it at cold temperatures, or fill with dry nitrogen, to prevent
moisture getting in at all - and have an enclosure that can withstand the high pressure differences as temperature changes (not
Most electronics generates a little heat which helps to prevent condensation on the circuit board - nearby metal objects are
more likely to get the condensation, so make sure the board isn't underneath metal objects than might drip - plastic or wooden enclosure with ventilation grill perhaps?