HOW TO USE TESTFOR ITEM ON THE GROUND || Minecraft PE Command
Cookie announcer[]
When run in order, such as in a chain of command blocks or functions, these commands will give a random player 5 cookies.
/tag @r add cookie /give @a[tag=cookie] minecraft:cookie 5 /say @a[tag=cookie] has been given 5 cookies! /tag @a[tag=cookie] remove cookie
Proximity Mine[]
By using a condition such as /execute if entity @p[distance=..5,name=! hooked to a short clock and one or more TNT blocks via a comparator, the command block can act as an undetectable proximity mine against all players except the placing player.
Wireless redstone[]
Redstone can wirelessly be transmitted by placing a redstone block at a certain location. The downside to this method is that the chunks being transmitted to must be loaded. This method is often used with Adventure maps to trigger more command blocks.
/setblock /setblock
To not require loading chunks, the scoreboard is needed. The second command will only complete successfully if the first has been run. Either a comparator or chained conditional command blocks can detect the success. The second command block should be set to repeat.
/scoreboard objectives add signal dummy /scoreboard objectives remove signal
FAQ
How do you detect if an entity is on the ground?
Is there a detect command in Minecraft?
How do you identify an item in Minecraft?
How do you show things on the floor in Minecraft?