The Open Source Electronic Spawn Point (ESP) Project

Anonymous (not verified)

05 Jul 2014

One year ago, during an OP in France, my buddy Ematiel and I experienced what a lot of airsoft players experienced before. It was a game of conquest like in the Battlefield video game. The spawns were held by raising our flag and lowering the enemy’s. BUT, we couldn’t respawn at a spawn that was under enemy fire. During THE WHOLE GAME, the referees had to stick next to the spawns to say if it was under fire or not as; and as soon as the game began, there were complaints of players respawning under fire.

(Ematiel at the said OP in France)

Ematiel and I are Engineers in Electronics and we wanted to find a solution to this problem. Ematiel was the first to come up with the good idea --- we had to find a way to detect BBs on the spawn, and the best way was to put a target on the spawn to deactivate it if the target was hit. After some searching and an alpha version that came with some troubles, we finally found out how to detect those BBs and how to spot from at least 50m if the spawn was held by a team or if it was neutral. The Electronic Spawn Point (ESP) was born.

HOW IS IT MADE?

First of all, it has the hit detection system: It is composed of a digital sound detector with a configurable threshold that is put inside a box made out of plastic (we used an empty 1kg powder chocolate box which can handle 0.20grBB/400fps @ 2m). The trick is to set the threshold to detect a hit but not the sound of someone firing near of the target. This threshold is set by a potentiometer, if you set it right, it won’t be triggered even if you shoot another target that is standing next to it.

(Inside the ESP Box)

The second important thing is that the status of the spawn should be seen at least at 50m. We first tried light beacons but in daylight they are hardly visible and they consume a lot of energy. We, then, decided to use a servo to raise and lower the flags. 3 positions are used, 1 for each team and in the middle for neutral. Flags with a string and a stick screwed to the servo are what you need to have a clearly identifiable status from 50m at least.

(Photo of the Servo and the flags)

Last but not least, the ESP is driven by an arduino UNO board. We chose it because it is very easy to program, cheap and allows us to upgrade the ESP only by code. For purposes of future updates, we added an LCD screen (the same as your old Nokia 5110) to be able to print the time each team owned the spawn or other things that could come to mind of those who want to invest time in this project.

(ESP's Arduino)

Everything is powered by a 9.6v 1600mAh NiMh AEG battery that gives the ESP a continuous operating time of approximately 24 hours.

HOW TO USE IT?

To boot it up, you just need to plug the battery in. At boot you will see on the screen the logo of our team (Breizh Skulls Company) and the label “FREE” that says the spawn is neutral.

When a red player comes to the ESP he pushes the red button and keeps on pushing during 30 seconds. After that the red flag raises and the blue one lowers and the screen displays “RED”.

If a blue team member comes and pushes the blue button, after 1 second the spawn point becomes neutral (both flags have the same height) and if he continues pushing the button for 30 seconds his flag will rise and until the screen will display “BLUE”. The screen displays the time you are pushing on the button.

If the spawn point is owned by a team, any hit on the target will put IMMEDIATELY the ESP into the neutral position AND it won’t be able to be owned again in the next minute. A hit on a neutral ESP is useless and won’t inhibit the ESP for 1 minute.