well, that depends, what type of camping are you planning on doing, and what sort of area?
whether you tent camp, as i suspect from your avatar image, or RV camp, i would basically recommend a first-aid kit, and some basic survival gear, just in case (we hope it never needs to be used).
the last time i tent camped (i was 15yrs at the time), i made sure i had a first-aid kit, compass, maps of the area, plenty of food and water, plus a method to purify water (used liquid iodine drops at the time). i would recommend at least a set or two of extra clothing, in case you get caught in the rain. speaking of rain, my pack had a plastic liner, but i think people just use dry-sacks now, to protect clothing, bedding, ect.
i can't remember all i took as it was quite some time ago.
as i have a packable camp stove, i like to take Knorr pasta and rice meals. example like below:
Amazon.com : KNORR Pasta Sides, Creamy Chicken, 4.2 oz : Grocery & Gourmet Food
they are dehydrated meals that you add water, and sometimes some milk to, and cook. for milk, i take powdered milk, and add water. good enough for camping milk.
there may be something similar in your area.
the list can get quite large, but it depends on where you camp, for how long, and how close to the civilized world you are.
hope this is of some help for you. at least it may give you some ideas.
i really gotta get back into tent camping, i miss it.
EDIT: Knorr pasta sides are a lot cheaper at my local store, than on Amazon
so... i just re-read your post, and i took your post to be about general equipment, when you were asking about gadgets. sorry, my mistake.
my primary gadget would be my smartphone, as i then have GPS and communication if needed (if i have signal...)
secondary would be my Magellan Meridian Platinum handheld GPS for backup navigation. it is old, but still works great.
thirdly, i would bring some sort of 2-way radio, probably a CB radio (personal preference).
my Magellan GPS and CB radio both take the same batteries, so i would bring plenty of NEW batteries for spares, and a power-bank to charge my smartphone.
that's about all i would bring for gadgets, as more would kinda take away from the nature experience.