What am I doing wrong here? It's driving me crazy!

I've made an onGround function that check if there's a flagged sprite below you, which seems to be working, but when you run it, the gravity (which should kick in when not on the ground) never gets applied.

I've used the print function to debug whether onGround is working correctly and it is, so why is the

if not onground then
  dy+=grv
end

part not working?

x=60
y=112
dy=0
jmp=5
grv=0.5

function _update()
	jumping()

	y+=dy
end

function _draw()
 cls()
 map(0,0,0,0,16,16)
 spr(1,x,y)

 print(solid(x,y+9),1,1,7)
end

function jumping()
	-- jumping
	if onground and
	btnp(4) then
		dy=-jmp
	end
	-- gravity
	if not onground then
		dy+=grv
	end
	-- problem area above!!!!--
end

function solid(sx,sy)
 local tilex=flr(sx/8)
 local tiley=flr(sy/8)

 if fget(mget(tilex,tiley),0) then
 	return true
 else
 	return false
 end
end

function onground()
	if solid(x,y+9) or
	solid(x+8,y+9) then
		return true
	else
		return false
	end
end

from what you posted it looks like you are not actually ever calling the "onground" function; instead you are essentially checking for the existence of the function, so it always evaluates to true.

change "if onground" to "if onground()", etc.

You delightful angel!

Seems so obvious now :)